Dissertations / Theses: 'Soil salinization'

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Al-Zokair, Abdulaziz A. "An investigation of soil salinization in Al-Hassa Oasis, Saudi Arabia." Thesis, University of Exeter, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251100.

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Stals, Jacobus Petrus. "Mapping potential soil salinization using rule based object-oriented image analysis." Thesis, Stellenbosch : University of Stellenbosch, 2007. http://hdl.handle.net/10019.1/2371.

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Thesis (MSc (Geography and Environmental Studies))--University of Stellenbosch, 2007.
Soil salinization is a world wide environmental problem affecting plant growth and agricultural yields. Remote sensing has been used as a tool to detect and/or manage soil salinity. Object-oriented image analysis is a relatively new image analysis technique which allows analysis at different hierarchical scales, the use of relationships between objects and contextual information in the classification process, and the ability to create a rule based classification procedure. The Lower Orange River in South Africa is a region of successful irrigation farming along the river floodplain but also with the potential risk of soil salinization. This research attempted to detect and map areas of potential high soil salinity using digital aerial photography and digital elevation models. Image orthorectification was conducted on the digital aerial photographs. The radiometric variances between photographs made radiometric calibration of the photographs necessary. Radiometric calibration on the photographs was conducted using Landsat 7 satellite images as radiometric correction values, and image segmentation as the correction units for the photographs. After radiometric calibration, object-oriented analysis could be conducted on one analysis region and the developed rule bases applied to the other regions without the need for adjusting parameters. A rule based hierarchical classification was developed to detect vegetation stress from the photographs as well as salinity potential terrain features from the digital elevation models. These rule bases were applied to all analysis blocks. The detected potential high salinity indicators were analyzed spatially with field collected soil data in order to assess the capability of the classifications to detect actual salinization, as well as to assess which indicators were the best indicators of salinity potential. Vegetation stress was not a good indicator of salinity as many other indicators could also cause vegetation stress. Terrain indicators such as depressions in the landscape at a micro scale were the best indicators of potential soil salinization.

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Johnston, Christopher R. "Soil chemical and physical changes resulting from irrigation with coalbed natural gas co-produced water effects of soil amendments and water treatments /." Laramie, Wyo. : University of Wyoming, 2007. http://proquest.umi.com/pqdweb?did=1445033651&sid=10&Fmt=2&clientId=18949&RQT=309&VName=PQD.

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Beletse, Yacob Ghebretinsae. "The environmental impact and sustainability of irrigation with coal-mine water." Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-05242009-125253.

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Bahizire, François B. "Effect of salinity on germination and seedling growth of canola (Brassica napus L.) /." Link to the online version, 2007. http://hdl.handle.net/10019.1/1939.

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Mayorga, Maria Irles 1943. "Economic impacts of salinization in irrigated agricultural land : an Arizona case study." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/191135.

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The dynamics of salt accumulation in the soil over time is one of major important information input needed for decision-making in regard to irrigate with saline water. As all waters contain some dissolved salts, during the irrigation these salts tend to concentrate in the soil causing depressed plant growth. Saline irrigation water, low soil permeability, inadequate drainage conditions, low rainfall and poor irrigation management all contribute to the tendency of salt accumulation in the soil. The principal salt accumulation problem of economic importance arises when non-saline soils become saline as result of irrigation. The dynamics of salt accumulation in this study, is based on the model for tracing salt distribution in the soil affected by the quantity and quality of irrigation water, amount of nitrogen and initial soil salinity. To verify the model for tracing salt distribution in the soil and to statistically estimate a crop-production function and soil salinity relation, agronomic data were used from field experiment conducted at the University of Arizona, Maricopa Agricultural Center (MAC), during the 1985 growing season and that utilized cotton variety Delta Pine 61. From the point of view of the response functions and salt accumulation in the soil, many assumptions were made before formulating the models. Results show that (1) no conclusions could be drawn with respect to the model of salt accumulation in the soil, (2) in the case of yield production function and soil salinity relation, the water quantity coeffient had an absolute value greater than one, (3) water quality and nitrogen coefficients had an absolute value less than one, (4) initial soil salinity coefficient had negative value, (5) looking for the best combination amoung the variables inputs, the marginal rate of substitution was greater than the ratio of prices, (6) the time path for soil salinity converge to a steady state conditions, and (7) the profitability of cotton irrigated with drip system is sensitive to yield increases and increases in the price of cotton.

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Biddle, Dean Leslie. "Investigation of water-mineral interactions in gneissic terrain at Mt. Crawford, South Australia." Title page, contents and abstract only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phb584.pdf.

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Diskette for IBM/PC in pocket on back end paper. Copies of author's previously published articles inserted. Bibliography: leaves 186-207. An evaluation of spatial and temporal variation in composition of soil solutions collected from a hydro-toposequence with seasonally saturated soils ranging from Xeralfs to Aqualfs. The sub-catchment is under native eucalyptus and is formed from granite gneiss. The study shows that mineral weathering under eucalypt vegetation contributes substantially to the quantity of elements measured in soil solution with some aeolian salts. Migration of soil solutions to low lying areas promotes dryland salinity in these landscapes.

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Pourfathali, Kasmaei Leila. "Long Term Environmental Modelling of Soil-Water-Plant Exposed to Saline Water." Thesis, KTH, Mark- och vattenteknik (flyttat 20130630), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-99344.

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The impact of long term management strategies of irrigation with saline water in semi-arid region of Gordonia, South Africa is the highest interest to optimize water consumption, soil conservation, and crop yield for sustainable water allocations to human food production and ecosystem without irreversible damages to soil and water body. An integrated ecosystem assimilation, in shape of soil-water storage model based on physical approach for 30-year simulation run defined in form of digital ecosystem modelling with help of CoupModel tool to assemble together the most important underlying processes of soil hydraulics, irrigation demands, leaching fraction, evapotranspiration, salt transport. Two scenarios of water management strategy; surface as traditional and drip as subsurface irrigation considered to apply water and salt into the ecosystem model. Gaining high food production for human with respect to ecosystem sustainability, in each water management scenario studied by evaluating general and detailed result from water and salt balance for the entire simulation period plus long term nitrogen and carbon turnover as crop yield indicator. Non-productive water losses, salt accumulation in root zone, carbon and nitrogen turnover, salt transport to aquifer via deep percolation observed thoroughly. Decline in crop yield due to water and salt stress, conducted by monitoring biomass production with respect to water consumption and soil osmotic pressure in root zone. Drip scenario had better functionality to perform less water wastage by decreasing soil evaporation as non-productive water loss almost 40 %, however productive water consumption decreased 20 % due to insufficient leaching fraction and also salt accumulation increased in root zone. Precipitation had a significant role to accomplish leaching deficiency and removing salt from root zone. Salt accumulation flushed out from root zone by more leaching, though resulting more water wastage and more possibility of salinization threatening beneath aquifer. Ecosystem in terms of soil-water and plant responding differently facing salinity in different water management practices and salt as source of pollution could either stabilized in soil by accumulating in root zone causing anthropogenic soil desertification or percolate to beneath aquifer resulting aquifer salinization.

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Morgan, Karina School of Biological Earth &amp Environmental Sciences UNSW. "Evaluation of salinisation processes in the Spicers Creek catchment, central west region of New South Wales, Australia." Awarded by:University of New South Wales. School of Biological, Earth and Environmental Sciences, 2005. http://handle.unsw.edu.au/1959.4/24327.

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Spicers Creek catchment is located approximately 400 km west of Sydney in the Central West region of New South Wales, Australia. Dryland salinity has been recognised as a major environmental issue impacting soil and water resources in the Central West region of NSW for over 70 years. Due to the geological complexity of the catchment and the presence of high salt loads contained within the soils, groundwater and surface waters, the Spicers Creek catchment was identified as a large contributor of salinity to the Macquarie River catchment. Over fifty-two dryland salinity occurrences have been identified in the Spicers Creek catchment and it appears that dryland salinity is controlled by the presence of geological structures and permeability contrasts in the shallow aquifer system. Combinations of climatic, geological and agricultural factors are escalating salinity problems in the catchment. The main aim of this thesis was to identify the factors affecting salinisation processes in the Spicers Creek catchment. These include the role of geological structures, the source(s) of salts to the groundwater system and the geochemical processes influencing seepage zone development. To achieve these aims a multidisciplinary approach was untaken to understand the soils, geology, hydrogeology and hydrogeochemistry of the catchment. Investigative techniques employed in this project include the use of geophysics, soil chemistry, soil spectroscopy, hydrogeochemistry and environmental isotopes. Evaluation of high-resolution airborne magnetics data showed a major north-east to south-west trending shear zone. This structure dissects the catchment and several other minor faults were observed to be splays off this major structure. These structures were found to be conducive to groundwater flow and are influencing the groundwater chemistry in the fractured aquifer system. Two distinctive groundwater chemical types were identified in the catchment; the saline Na(Mg)-Cl-rich groundwaters associated with the fractured Oakdale Formation and the Na-HCO3-rich groundwaters associated with the intermediate groundwater system. The groundwater chemistry of other deep groundwaters in the catchment appears to be due to mixing between these end-member groundwaters within the fractured bedrock system. The spatial distribution of electrical conductivity, Cl-, Sr2+ and 87Sr/86Sr isotopic ratios showed the correlation between saline groundwaters and the location of faults. Elevated salinities were associated with the location of two crosscutting fault zones. The spatial distribution of HCO3-, K+, Li+ and ?????3CDIC highlighted the extent of Na-HCO3-rich groundwaters in the catchment and showed that these groundwaters are mixing further east than previously envisaged. These findings show that Na(Mg)-Cl-rich groundwaters are geochemically distinctive and have evolved due to extensive water-rock interaction processes within the fracture zones of the Oakdale Formation. These saline groundwaters contain elevated concentrations of trace elements such as As, V and Se, which pose a potential risk for water resources in the area. 87Sr/86Sr isotopic ratios indicated that the source of salinity to the Na(Mg)-Cl-rich groundwaters was not purely from marine or aerosol input. Salt is most likely contributed from various allochthonous and autochthonous sources. This research found that the main mechanism controlling the formation of dryland salinity seepage zones in the Spicers Creek catchment is due to the presence of geological structures. These groundwater seepage zones act as mixing zones for rainfall recharge and deeper groundwaters. The main sources of salt to the seepage zones are from deeper Na(Mg)-Cl-rich groundwaters and rainfall accession. The major importance of this research highlights the need for an integrated approach for the use of various geoscientific techniques in dryland salinity research within geologically complex environments.

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Barr, N. F. "Salinity control, water reform and structural adjustment : the Tragowel Plains Irrigation District /." Connect to thesis, 1999. http://eprints.unimelb.edu.au/archive/00000230/l.

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Yamasaki, Marcia Tiemi [UNESP]. "Influência da salinidade do fluido na avaliação da compactação e da resistividade elétrica de dois solos." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/92972.

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Made available in DSpace on 2014-06-11T19:26:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-05-11Bitstream added on 2014-06-13T20:34:06Z : No. of bitstreams: 1 yamasaki_mt_me_bauru.pdf: 2126849 bytes, checksum: 4896e264bafeff1d70577b538318f03e (MD5)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A resistividade elétrica vem sendo somada junto aos estudos de investigação geotécnica devido ao seu apelo ambiental, visto que esta técnica se dá por meio da imposição de um fluxo de corrente elétrica em uma amostra de solo, permitindo-se avaliar as condições geológicas locais por um método não destrutivo. A obtenção dessa medida vem sendo somada aos estudos de investigação geotécnica devido ao seu apelo ambiental, otimizando as amostragens e permitindo a avaliação das condições geológicas locais por meio de um método não destrutivo. Dessa maneira, o objetivo dessa dissertação de mestrado é avaliar, em laboratório, o comportamento da resistividade elétrica variando-se o teor de salinidade no fluido de percolação em dois solos tropicais: um arenoso, sedimentar, característico da região de Bauru, e outro argiloso, resultado do intemperismo do Diabásio, proveniente do município de Piracicaba. As análises foram realizadas utilizando-se resultados, dos ensaios de caracterização, compactação, permeabilidade e curva de retenção. o teor de salinidade do fluido foi considerado, tanto na compactação, como na percolação em três concentrações: água destilada, 250 ppm e 500 ppm de NaCI, além de abastecimento, controlando-se o teor de umidade, a compactação, o índice de vazios e o grau de saturação. Os resultados mostraram-se que a resistividade elétrica tende a ser constante no ramo úmido da curva de compactação e também quando o grau de saturação está acima de 80%. Notou-se também que a curva de resistividade versus sucção pode ser divida em dois trechos: o primeiro corresponde às baixas sucções, com a continuidade da água nos poros e resistividade menores; o segundo trecho, que se inicia na primeira entrada de dar, conduz a um nítido aumento nos valores de...
The electrical resitivity of a homogeneous material could be defined as the measurements of the difficult of crossing of the electrical current and it depends of the dimension and type of material. However, when that material is soil, composed by three phases (solid, liquid and gas), this measure is influenced by several factors that could be controlled in laboratory tests. The electrical resistivity has been used geotechnical research studies since this technique improve the sampling of environmental works and allowing the evaluation of local geological conditions through a non-destructive method. Thus, the goal of the study was evaluate the behavior of electrical resistivity of two tropical soils varying the salinity concentration in the percolation fluid: a sandy sediment, characteristic of the Bauru city; a clayey soil, Weathered of Diabase from Piracicaba City. Results of soil mechanics laboratory tests as characterization tests, compaction, permeability and soil-water retention curve were used in the analyses. In both, compaction and permeability tests, the procedure were carried out varying the fluid salinity: distilled water, water supply; 250ppm and 500ppm of NaCi. The moisture content, compaction energy, void ratio and degree of saturation. The tests results showed the rsistivity values tend to be constant in the wet density curve and when the degree of saturation is above 80%. It was also noted that the curve of resistivity suction could be divided into two segments: the first corresponds to low suctions where there is continuity of water in the porous leading to low resistivity values; the second segment begins in the first air entrance, with discountinuous state of pore-water and sa sharphy increase in the resistivity values. The formation factors (FF) were obtained during the permeability tests: 7,5 to the sandy soil and... (Complete abstract click electronic access below)

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Whitlark, Brian Stephen. "Irrigation of High Maintenance Turf Using the Arizona Department of Water Resources Water Duty: Evaluation of Turf Performance and the Potential for Soil Salinization." Thesis, The University of Arizona, 1999. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_etd_hy0008_m_sip1_w.pdf&type=application/pdf.

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Yamasaki, Marcia Tiemi. "Influência da salinidade do fluido na avaliação da compactação e da resistividade elétrica de dois solos /." Bauru : [s.n.], 2012. http://hdl.handle.net/11449/92972.

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Orientador: Anna Silvia Palcheco Peixoto
Banca: Vagner Roberto Elis
Banca: George de Paula Bernardes
Resumo: A resistividade elétrica vem sendo somada junto aos estudos de investigação geotécnica devido ao seu apelo ambiental, visto que esta técnica se dá por meio da imposição de um fluxo de corrente elétrica em uma amostra de solo, permitindo-se avaliar as condições geológicas locais por um método não destrutivo. A obtenção dessa medida vem sendo somada aos estudos de investigação geotécnica devido ao seu apelo ambiental, otimizando as amostragens e permitindo a avaliação das condições geológicas locais por meio de um método não destrutivo. Dessa maneira, o objetivo dessa dissertação de mestrado é avaliar, em laboratório, o comportamento da resistividade elétrica variando-se o teor de salinidade no fluido de percolação em dois solos tropicais: um arenoso, sedimentar, característico da região de Bauru, e outro argiloso, resultado do intemperismo do Diabásio, proveniente do município de Piracicaba. As análises foram realizadas utilizando-se resultados, dos ensaios de caracterização, compactação, permeabilidade e curva de retenção. o teor de salinidade do fluido foi considerado, tanto na compactação, como na percolação em três concentrações: água destilada, 250 ppm e 500 ppm de NaCI, além de abastecimento, controlando-se o teor de umidade, a compactação, o índice de vazios e o grau de saturação. Os resultados mostraram-se que a resistividade elétrica tende a ser constante no ramo úmido da curva de compactação e também quando o grau de saturação está acima de 80%. Notou-se também que a curva de resistividade versus sucção pode ser divida em dois trechos: o primeiro corresponde às baixas sucções, com a continuidade da água nos poros e resistividade menores; o segundo trecho, que se inicia na primeira entrada de dar, conduz a um nítido aumento nos valores de... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The electrical resitivity of a homogeneous material could be defined as the measurements of the difficult of crossing of the electrical current and it depends of the dimension and type of material. However, when that material is soil, composed by three phases (solid, liquid and gas), this measure is influenced by several factors that could be controlled in laboratory tests. The electrical resistivity has been used geotechnical research studies since this technique improve the sampling of environmental works and allowing the evaluation of local geological conditions through a non-destructive method. Thus, the goal of the study was evaluate the behavior of electrical resistivity of two tropical soils varying the salinity concentration in the percolation fluid: a sandy sediment, characteristic of the Bauru city; a clayey soil, Weathered of Diabase from Piracicaba City. Results of soil mechanics laboratory tests as characterization tests, compaction, permeability and soil-water retention curve were used in the analyses. In both, compaction and permeability tests, the procedure were carried out varying the fluid salinity: distilled water, water supply; 250ppm and 500ppm of NaCi. The moisture content, compaction energy, void ratio and degree of saturation. The tests results showed the rsistivity values tend to be constant in the wet density curve and when the degree of saturation is above 80%. It was also noted that the curve of resistivity suction could be divided into two segments: the first corresponds to low suctions where there is continuity of water in the porous leading to low resistivity values; the second segment begins in the first air entrance, with discountinuous state of pore-water and sa sharphy increase in the resistivity values. The formation factors (FF) were obtained during the permeability tests: 7,5 to the sandy soil and... (Complete abstract click electronic access below)
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Aluvilu, Anastasia N. "Responses of capsicum frutescenes cultivar serrano and capsicum annuum cultivar capistrano to meloidogyne incognita race 2,salinity and growth period." Thesis, University of Limpopo (Turfloop Campus), 2010. http://hdl.handle.net/10386/858.

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Silva, Alexandre Reuber Almeida da. "Responses and adaptations of coconut plants "Green Dwarf" to interactions between water stress and soil salinity." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14726.

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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
In this work morphological, physiological, biochemical and nutritional responses, to elucidate the possible adaptive strategies of young coconut plants, cultivating "Green Dwarf", involved with tolerance to the effects of stress isolated and combined soil salinity and water stress. In the experiment, conducted in a greenhouse, the greenhouse type, in Fortaleza, CearÃ, were evaluated under statistical design of randomized blocks in a split plot arrangement, the effects of different levels of water stress by imposing different percentages resets the potential evapotranspiration - ETpc (20; 40; 60; 80 and 100%), related to increasing levels of soil salinity (1.72, 6.25, 25.80 and 40.70 dS m-1) provided by soils derived from the Irrigated Perimeter Morada Nova - PIMN. The effects of treatments on plants were evaluated using the variables: plant height, leaf number, stem diameter, leaf area, biomass production (root, shoot and total), compared root dry biomass of aerial-1, to salinity tolerance indices, leaf gas exchange (stomatal conductance, transpiration, photosynthesis, instant and intrinsic efficiency of water use), quantum yield of chlorophyll fluorescence (Fv Fm-1) level for total chlorophyll (Spad index) , total content of chlorophyll (a + b) and carotenoids, leaf water potential, leaf and root levels of inorganic solutes (potassium ions, sodium and chloride) and organic (total soluble carbohydrates, N - aminossolÃveis and free proline) and nutritional state (foliar nutrients of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, copper, manganese and zinc). The growth and biomass production of the plants are sharply reduced by the conditions of water stress and high soil salinity, apparently being more critical to fluid restriction culture. The degree of water stress can enhance the susceptibility to salinity. The physiological mechanisms are effectively limited when water stress and salinity act separately and / or together. The effects of water stress are more effective in the reduction of physiological parameters, to the detriment soil salinity. The magnitudes of physiological responses of plants to water supply and salinity depend on the intensity of stress. Adaptive physiological responses of plants are related mainly to stomatal regulation. In conditions of drought and soil salinity, the plants have linear reductions in the total levels of chlorophyll. Carotenoid levels respond to the combined effects of water availability and soil salinity and reflect the antagonism between them. The coconut has a number of physiological adjustments mechanisms that give the species a partial tolerance to drought stress and / or saline. Saline ions K+, Na+ and Cl- accumulate significantly in young coconut plants, to the detriment of organic solutes, both in the leaves and in the roots, evidencing an apparent root retention ions. Salinity did not change the concentration of organic solutes, however, show up increments in leaf and root levels of free proline in response to water stress. Water stress and soil salinity interact, affecting the nutritional status of plants, except for the nutrient P. Leaf contents of nutrients N, Ca, S, Fe, Mn and Zn grow positively with the increase of water availability and are reduced substantially with increasing salinity. The interaction of smaller water deficit levels with the highest saline levels maximizes the leaf contents of Mg and Cu and minimizes K. During the establishment of coconut seedlings, the need for macronutrients follows the descending order: N, K Ca, Mg, S and P and micronutrients: Fe, Mn, Zn and Cu. The plant nutrition proved to be adequate, except for the imbalances observed in nutrients K, Mg, S and Mn. The coconut seedlings show full capacity of the establishment in saline soils PIMN, corresponding to the level of electrical conductivity to 6.50 dS m-1, but only when the water supply remains adequate. For the higher salinity levels the plants survive, yet the size of the same is reduced by around 50%, even when fully irrigated.
Neste trabalho foram estudadas repostas morfolÃgicas, fisiolÃgicas, bioquÃmicas e nutricionais, visando elucidar as possÃveis estratÃgias adaptativas de plantas jovens de coqueiro, cultivar âAnÃo Verdeâ, envolvidas com sua tolerÃncia aos efeitos dos estresses isolados e/ou combinados, salinidade do solo e deficiÃncia hÃdrica. No experimento, conduzido em casa de vegetaÃÃo, do tipo telado, em Fortaleza, CearÃ, avaliaram-se, sob delineamento estatÃstico de blocos casualizados, no arranjo de parcelas subdivididas, os efeitos de diferentes nÃveis de deficiÃncia hÃdrica, mediante a imposiÃÃo de distintos percentuais de reposiÃÃes da evapotranspiraÃÃo potencial da cultura - ETpc (20; 40; 60; 80 e 100%), associados Ã crescentes nÃveis de salinidade do solo (1,72; 6,25; 25,80 e 40,70 dS m-1), proporcionados pelos solos oriundos do PerÃmetro Irrigado Morada Nova - PIMN. Os efeitos dos tratamentos sobre as plantas foram avaliados por meio das variÃveis: altura de plantas, nÃmero de folhas, diÃmetro do caule, Ãrea foliar, produÃÃo de biomassa (radicular, parte aÃrea e total), relaÃÃo biomassa seca raiz parte aÃrea-1, Ãndices de tolerÃncia Ã salinidade, trocas gasosas foliares (condutÃncia estomÃtica, transpiraÃÃo, fotossÃntese, eficiÃncia instantÃnea e intrÃnseca de uso da Ãgua), rendimento quÃntico da fluorescÃncia da clorofila a (Fv Fm-1), teores relativos de clorofila total (Ãndice Spad), teores totais de clorofilas (a+b) e de carotenÃides, potencial hÃdrico foliar, teores foliares e radiculares dos solutos inorgÃnicos (Ãons potÃssio, sÃdio e cloreto) e orgÃnicos (carboidratos solÃveis totais, N - aminossolÃveis e prolina livre) e estado nutricional (teores foliares dos nutrientes nitrogÃnio, fÃsforo, potÃssio, cÃlcio, magnÃsio, enxofre, ferro, cobre, manganÃs e zinco). O crescimento e a produÃÃo de biomassa das plantas sÃo acentuadamente reduzidos pelas condiÃÃes de restriÃÃo hÃdrica e de elevada salinidade do solo, sendo aparentemente mais crÃtica Ã cultura a restriÃÃo hÃdrica. O grau de estresse hÃdrico Ã capaz de acentuar a suscetibilidade Ã salinidade. Os mecanismos fisiolÃgicos sÃo efetivamente limitados quando a deficiÃncia hÃdrica e a salinidade atuam isoladamente e/ou em conjunto. Os efeitos do estresse hÃdrico se mostram mais efetivos nas reduÃÃes dos parÃmetros fisiolÃgicos, em detrimento Ã salinidade do solo. As magnitudes das respostas fisiolÃgicas das plantas ao suprimento hÃdrico e Ã salinidade dependem das intensidades do estresses. As respostas fisiolÃgicas adaptativas das plantas estÃo relacionadas, principalmente, Ã regulaÃÃo estomÃtica. Em condiÃÃes de dÃficit hÃdrico e de salinidade do solo, as plantas apresentam reduÃÃes lineares nos teores totais de clorofilas. Os teores de carotenÃides respondem aos efeitos combinados da disponibilidade hÃdrica e da salinidade do solo e refletem o antagonismo entre estes. O coqueiro apresenta uma sÃrie de mecanismos de ajustes fisiolÃgicos que conferem Ã espÃcie uma parcial tolerÃncia ao estresse hÃdrico e/ou salino. Os Ãons salinos K+, Na+ e Cl- acumulam-se significativamente em plantas jovens de coqueiro, em detrimento aos solutos orgÃnicos, tanto nas folhas quanto nas raÃzes, sendo evidenciada uma aparente retenÃÃo radicular de Ãons. A salinidade nÃo altera os teores dos solutos orgÃnicos, todavia, denotam-se incrementos nos teores foliares e radiculares de prolina livre em resposta Ã deficiÃncia hÃdrica. A deficiÃncia hÃdrica e a salinidade do solo interagem, afetando o estado nutricional das plantas, excetuando o nutriente P. Os teores foliares dos nutrientes N, Ca, S, Fe, Mn e Zn crescem positivamente com a ampliaÃÃo da disponibilidade hÃdrica e reduzem-se substancialmente com o aumento da salinidade. A interaÃÃo dos menores nÃveis de deficiÃncia hÃdrica com os maiores nÃveis salinos maximiza os teores foliares de Mg e Cu e minimiza os de K. Durante o estabelecimento das plantas jovens de coqueiro, a necessidade de macronutrientes obedece Ã ordem decrescente: N, K Ca, Mg, S e P e Ã de micronutrientes: Fe, Mn, Zn e Cu. A nutriÃÃo das plantas mostra-se adequada, excetuando-se, os desequilÃbrios observados nos nutrientes K, Mg, S e Mn. As plantas jovens de coqueiro mostram plena capacidade de estabelecimento nos solos salinizados do PIMN, atÃ o nÃvel de condutividade elÃtrica correspondente a 6,50 dS m-1, porÃm apenas quando o suprimento hÃdrico se mantÃm adequado. Para os nÃveis de salinidade mais elevados as plantas sobrevivem, contudo o porte das mesmas reduz-se em torno de 50%, mesmo quando plenamente irrigadas.

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Urbano, Vanessa Ribeiro. "Aplicação de água de reúso tratada no cultivo de alface (Lactuca sativa L.)." Universidade Federal de São Carlos, 2013. https://repositorio.ufscar.br/handle/ufscar/14.

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Universidade Federal de Minas Gerais
The concern in developing strategies to solve the water scarcity problem is growing and actual. As a big consumer of the available fresh water, agriculture is the activity with the biggest potential for applying of water reuse. This study set up in CCA/UFSCar evaluated, on laboratory conditions, the physical and chemical properties of a soil irrigated with treated wastewater after the application of a water sheet corresponding to five cycles of lettuce s growth (Lactuca sativa, L.) and in a greenhouse, evaluated the sanitary characteristics and mass of the Elisa type lettuce and the physical, chemical and microbiological characteristics of the soil after the cultivation with treated wastewater, comes from the wastewater treatment plant from the university. In the laboratory experiment, eighteen undisturbed soil samples were coupled in a constant head permeameter and received a water sheet corresponding to five cycles of lettuce s growth, 0.58, 1.16, 1.74, 2.32 and 2.9 L of water for each cycle. The soil samples were distributed in five groups that received treated wastewater and one control group that received distilled water. Soil samples were collected to analyze the granulometry, saturated hydraulic conductivity (ksat), exchangeable sodium percentage (ESP) and soil fertility. Treated wastewater and distilled water leached samples were collected to analyze the electrical conductivity, sodium adsorption ratio (SAR), turbidity, pH, sodium, potassium, magnesium, phosphorus, calcium and nitrate. In a greenhouse, two cycles of Elisa lettuce were cultivated with two treatments (treated wastewater and supply water) with four repetitions. After the harvest of the lettuce, soil samples were collected to analyze granulometry, density, ksat, and soil fertility, total coliforms, Escherichia coli and heterotrophic. The harvested lettuces were analyzed for total coliforms, Escherichia coli and chemical analysis of plant tissue. In laboratory, there was an increase of ESP and the concentration of phosphorus and sodium on soil after the application of the water sheet. There wasn t significant difference on the physical properties of soil, turbidity and SAR. In a greenhouse, there wasn t significant difference between the treatments on nutrients absorption of lettuces cultivated, but the weight of lettuces irrigated with wastewater was 100% greater than the lettuces irrigated with supply water on the second cycle. It was not detected the presence of Esherichia coli on the cultivated lettuces, but there was total coliforms contamination, that presents a risk of contamination to the consumer. The irrigation with treated wastewater increased the nutrients on soil and the SAR indicated a soil salinization risk. The treated wastewater does not cause damage on the physical properties of soil.
A preocupação em desenvolver estratégias para minimizar o problema da escassez de água é crescente e atual. Como grande consumidora da água doce disponível, a agricultura é o setor com maior potencial de aplicação da água de reúso. Este trabalho desenvolvido no CCA/UFSCar avaliou, em laboratório, as propriedades físicas e químicas do solo irrigado com água de reúso tratada após aplicação de lâmina de irrigação correspondente ao cultivo de cinco ciclos de alface (Lactuca sativa L.) e, em casa de vegetação, as características sanitárias e a massa da cultura de alface Elisa e as características físicas, químicas e microbiológicas do solo após o cultivo com água de reúso, proveniente da estação de tratamento de esgoto da universidade. No experimento em laboratório, dezoito amostras indeformadas de solo foram acopladas em permeâmetro de carga constante e receberam lâmina de irrigação referente a cinco ciclos de cultivo de alface, 0,58, 1,16, 1,74, 2,32 e 2,9 L de água para cada ciclo. As amostras foram divididas em cinco grupos que receberam água de reúso e um grupo controle, que recebeu água destilada. Amostras de solo foram coletadas para determinar a granulometria, condutividade hidráulica saturada (ksat), porcentagem de sódio trocável (PST) e fertilidade do solo. Amostras da água de reúso e água destilada lixiviadas foram coletadas para determinar a condutividade elétrica, razão de adsorção de sódio (RAS), turbidez, pH, sódio, potássio, magnésio, fósforo, cálcio e nitrato. Em casa de vegetação, dois ciclos de alface "Elisa" foram cultivados com dois tratamentos (água de reúso e de abastecimento) com quatro repetições. Após a colheita, amostras de solo foram coletadas para determinar a granulometria, densidade, ksat, fertilidade do solo, coliformes totais, Escherichia coli e heterotróficos. Nas alfaces colhidas foram determinados os coliformes totais, Escherichia coli e análise química do tecido vegetal. Em laboratório, houve aumento da PST e teor de fósforo e sódio no solo após aplicação das lâminas de irrigação. Não houve diferença significativa nas propriedades físicas do solo, turbidez e RAS. Na casa de vegetação, não houve diferença significativa entre os tratamentos na absorção de nutrientes pelas alfaces cultivadas, porém, a massa das alfaces irrigadas com água de reúso foi 100% maior que a das alfaces irrigadas com água de abastecimento no segundo ciclo. Não foi detectada presença de Escherichia coli nas alfaces cultivadas, mas houve concentração de coliformes totais, o que representa risco de contaminação ao consumidor. A irrigação com água de reúso aumentou o teor de nutrientes no solo e a RAS indicou risco de salinização. A água de reúso não causou alterações nas propriedades físicas do solo.

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Oliveira, Paulo Alceu dos Santos. "Aspectos de solos salinizados e remediação no Estado de Sergipe." Universidade Federal de Sergipe, 2015. https://ri.ufs.br/handle/riufs/4125.

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Soil salinization and sodification are amongst the main land degradation processes. This evergrowing issue reaches worldwide proportions and takes place mostly in arid and semiarid regions of the world, including the Brazilian northeast and the state of Sergipe. It is caused mostly by anthropic activities such as inadequately irrigated agriculture, soil preparation and indiscriminate use of chemical fertilizers, in combination with weather conditions and soil characteristics. These phenomena have led to the decrease in agricultural productivity, increased soil treatment coss and land abandonment. Solutions to this problem demand integrated approaches that combine knowledge in agricultural, environmental, social and economic sciences. The goal of this work is to investigate predisposing conditions and the presence of soil salinization processes, identifying its inception and manifestation elements on the land reform settlement project Jacaré-Curituba, as well as to test the development of the plant Chrysopogon zizanioides (L.) Roberty in the settlement soil, analyzing salty soil´s potential for phytoremediation. The study was guided by theoretical frameworks that address the causes, consequences, control and mitigation options for the processes of soil salinization; field research for conduction of interviews; collection and analysis of different soils; and experiments with ten genotypes of the Chrysopogon zizanioides (L.) Robertyspecies in greenhouse soils with three different salinization levels. The study concludes by identifying, on the settlement project, the existence of salty soil due to pedoclimatic conditions and the adoption of agricultural techniques that foster the salinization process. On the greenhouse experiment there were significant differences of plant development when exposed to increased soil salinity and sodicity. The level of soil salts extraction was low, however, due to the salinity and sodicity tolerance showed by the plant, it was identified promising potential of vetiver for phytoremediation of saline soils by mechanisms related to improving the conditions of soil by growing roots and leaves.
A salinização e sodificação dos solos estão entre os principais processos de degradação da terra. O problema é crescente e tem extensão global, ocorrendo majoritariamente em regiões áridas e semiáridas do mundo, inclusive no Nordeste brasileiro e no estado de Sergipe. São causados em grande parte por atividades antrópicas, a exemplo da agricultura praticada com técnicas inadequadas de irrigação, de preparo de solo e de aplicação indiscriminada de adubos químicos, aliadas a condições predisponentes do clima e das características do solo. Têm causado perda de produtividade agrícola, custos elevados de tratamento e abandono da terra. A solução do problema exige abordagens integradas que envolvem conhecimentos das ciências agronômicas, ambientais, sociais e econômicas. O objetivo deste trabalho é levantar as condições predisponentes e a existência do processo de salinização de solo, identificando sua concepção e forma de ocorrência no assentamento de reforma agrária Jacaré-Curituba e testar, em casa de vegetação, o desenvolvimento da planta Chrysopogon zizanioides (L.) Roberty, em solos provenientes deste assentamento, que apresentam, em condição de campo, níveis diferentes de salinidade advindas das atividades agrícolas, avaliando seu potencial de fitorremediação de solos salinizados. O estudo foi pautado em referenciais teóricos que abordam as causas, consequências, formas de controle e remediação dos processos de salinização dos solos; em pesquisa de campo com realização de entrevistas; coleta e análise de solos; e experimentos com dez acessos da espécie Chrysopogon zizanioides (L.) Roberty em solo com três níveis diferentes de salinização, em casa de vegetação. Identificou-se no assentamento Jacaré-Curituba, a existência de processo de salinização do solo devido a uma associação de condições naturais predisponentes e adoção de práticas agrícolas contribuintes. No experimento em casa de vegetação, o desenvolvimento do vetiver foi afetado negativamente quando exposto a um aumento da salinidade e sodicidade do solo. O nível de extração de sais do solo foi baixo, no entanto, devido à tolerância à salinidade e sodicidade apresentada pela planta, foi identificado potencial promissor do vetiver para fitorremediação de solos salinizados através de outros mecanismos relacionados à melhoria das condições de solo ocasionada pela presença das folhas e principalmente das raízes.

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Bahizire, Francois B. "Effect of salinity on germination and seedling growth of Canola (Brassica napus L.)." Thesis, Stellenbosch : University of Stellenbosch, 2007. http://hdl.handle.net/10019.1/1939.

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Thesis (MScAgric (Agronomy)--University of Stellenbosch, 2007.
Soil salinity is a serious constrain to crop production in many countries. In the Western Cape canola production area, large variability in soil properties within the same field is a very common feature. Some of this variability may be ascribed to differences in salinity. These saline patches affected the germination and survival of cereal crops like wheat and may therefore also be a reason for the high variability and generally low canola yields obtained in this area. It will therefore be important to quantify the effect of such saline conditions on the germination and seedling establishment of canola in an effort to improve yields. In this study several experiments were conducted under controlled conditions in either Petri dishes in an incubator or pots in a temperature controlled glasshouse to determine the salinity response of canola. Results of the experiments done in Petri dishes, showed that the germination response of canola (Brassica napus L., cv. Tornado) to increasing levels of salinity is very similar to that of wheat (Triticum aestivum L., cv SST 88). Although canola germinated more rapidly than wheat at a temperature of 20 ºC, the final percentage germination for both crops decreased severely when NaCl induced salinity exceeded levels of an EC of 8 dS m-1, but less severe responses were obtained with NaCl/CaCl2 induced salinity. Under soil conditions an interaction between soil type and salinity level showed that the responses in sandy soil to an increase in salinity from 0 to 8 iv dS m-1 were less severe than in loamy soil and especially when salinity stress was induced by NaCl. Although cultivar Spektrum showed more tolerance to saline conditions during the germination and seedling stages in pot experiments when compared to other cultivars tested, these results will have to be confirmed in field trails where grain yield and quality can be measured.

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Wannakomol, Akkhapun. "Soil and groundwater salinization problems in the Khorat Plateau, NE Thailand integrated study of remote sensing, geophysical and field data = Probleme der Boden- und Grundwasserversalzung in der Khorat Hochebene, NE Thailand /." [S.l. : s.n.], 2005. http://www.diss.fu-berlin.de/2005/210/index.html.

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Silva, Neto Manoel Faustino da. "A problemática da salinização do solo no perímetro irrigado de São Gonçalo - PB." Universidade Federal da Paraíba, 2013. http://tede.biblioteca.ufpb.br:8080/handle/tede/5838.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Salinization appears as one of the main present problems in semiarid irrigated areas of the Northeast Region, leading to environmental and economic losses. This study consisted of a degradation analysis of natural resources and the impacts brought up by inadequate soil use in the São Gonçalo Irrigated Perimeter. In order to analyze this problem, the following methodological procedures were carried out: map elaboration for soil use; field research with collection samples of water (6 samples), and of soil (157 samples) for a laboratorial analysis, and questionnaires in a universe of 100 colonists for a secondary data collection. Results found showed that: the Perimeter is, mostly, made up of soils with a great salinization tendency; many pieces of land are cultivated with well-water with high concentrations of salt in solution; the flooding irrigation method is one of the irrigation types used, also contributing for local salinization: plantations with the most remarkable PISG production are of a vegetal type which have high productive levels even in salinization (coconut and rice); many spaces are abandoned or utilized for cattle-raising because they do not offer any agricultural productivity conditions any longer; most of the irrigators have salinization problems in their allotments; 51,78% of the PISG territory have high salinity levels, making it difficult for agriculture to develop with species that are not adapted to such conditions; a considerable part of the irrigators appear to be unaware of what motivates the problem of salinization and do not know the fact that the irrigation methods and the water utilized creates or intensifies this process; most of the irrigators do not have technical maintenance, making the cultivation without the technical knowledge demanded by irrigated agriculture; there is great dissatisfaction by the irrigators towards the present situation of the Perimeter s infrastructure, and problems about roads and the occurrences of obstructions in drainage and irrigation channels were the main complaints. Based on what was observed, we believe that, although benefits able to be obtained by the use of irrigated agriculture are incontestable, it is also undeniable that they may bring remarkable impacts over the environment. Taking into account that the reality observed in PISG is part of many of the perimeters irrigated in the Brazilian semiarid, a sense of reflection over these areas as well as the present activity arouse.
A salinização constitui-se em um dos principais problemas existentes nas áreas irrigadas do semiárido nordestino, provocando danos econômicos e ambientais. Este trabalho consistiu em uma análise da degradação dos recursos naturais e os impactos gerados pelo manejo inadequado do solo no Perímetro Irrigado de São Gonçalo. Para analisar esta problemática, foram tomados os seguintes procedimentos metodológicos: elaboração de mapa de uso do solo; pesquisas de campo, com a coleta de amostras de água (6 amostras) e de solo (157 amostras) para posterior análise em laboratório, e aplicação de questionários em um universo de 100 colonos para coleta de dados secundários. Os resultados encontrados mostraram que: o Perímetro é composto em grande parte do seu território por solos com grande tendência a salinização; muitos lotes são cultivados com a utilização de água de poços com altos teores de sais em solução; o método de irrigação por inundação é uma das formas de irrigação utilizadas, também contribuindo para a salinização local; os plantios que possuem maior destaque na produção do PISG são de espécies vegetais que obtém bons níveis produtivos, mesmo em situação de salinidade (coco e arroz); muitos espaços são abandonados ou utilizados para a pecuária por não apresentarem mais condições de produtividade agrícola; a maior parte dos irrigantes possuem problemas de salinização em seus lotes; 51,78% do território do PISG possui teores elevados de sais, dificultando o desenvolvimento da agricultura com espécies não adaptadas a estas condições; uma parte bastante considerável dos irrigantes não sabe o que motiva o problema da salinização, não tendo o conhecimento que os métodos de irrigação e a água utilizada criam ou intensificam esse processo; a maior parte dos irrigantes não possui assistência técnica, exercendo o cultivo sem os conhecimentos técnicos que a agricultura irrigada exige; ocorre grande insatisfação dos irrigantes para com a atual situação da infraestrutura do Perímetro, tendo como principais queixas problemas referentes às estradas e a ocorrência de obstrução dos drenos e dos canais de irrigação. Com base no que foi observado, acreditamos que apesar de serem incontestáveis os benefícios capazes de serem obtidos pelo uso da agricultura irrigada, não se pode negar também que estes podem gerar impactos notáveis ao ambiente. Levando em consideração que a realidade observada no PISG faz parte de muitos dos perímetros irrigados no semiárido brasileiro, urge um repensar sobre essas áreas, assim como a própria atividade em questão.

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Greenwood, Wm Jason. "Mapping porewater salinity with electromagnetic and electrical methods in shallow coastal environments, Terra Ceia, Florida." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000352.

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MIRANDA, Márcio Fléquisson Alves. "Diagnóstico e recuperação de solos afetados por sais em perímetro irrigado do sertão de Pernambuco." Universidade Federal Rural de Pernambuco, 2013. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5367.

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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
In Northeastern Brazil, in recent decades, with the increase of irrigation using in irrigated perimeters, often with inadequate management to local conditions, the soil salinization and sodification processes have intensified, promoting degradation and abandonment of large areas previously productive. Thus, we carried out a field survey to investigate the soil degradation in irrigated perimeter situated in the municipality of Custodia, semiarid region in Pernambuco, Brazil. Firstly were identified areas with degraded soils by salts excess, and also was done the experiment assembly with the intent to recover those areas through the application of organic and chemicals compounds, besides the technique of phytoremediation with Atriplex nummularia. For that, soil samples were taken in all 55 plots that make up the perimeter in the 0-10, 10-30 and 30-60 cm layers for the soils physical and chemical characterization, and chemical analyzes of the water used on the perimeter during periods of July/2009, January/2010, July/2010 and January/2011. After the selection of the degraded area into the irrigated perimeter, was mounted an experiment to recover the degraded soil by the evaluation of the treatments: 1) planting of Atriplex nummularia Lindl, 2) application of bovine manure, 3) sheep manure, 4) polymer, 5) gypsum and 6) control (witness). Four samples were taken, the first being at the same time of the experiment assembly (October 2009). After that, three more samples were taken, at six (April 2010), twelve (October 2010) and eighteen months (April 2011) after experiment assembly. Soil samples were collected at 0-10, 10-30 and 30-60 cm depth for the chemical analyzes. To evaluate the physical properties, soil samples were collected in the first (October 2009) and in the last (April 2011) collection at 0-10 and 10-30 cm layers. Were monitored the soil attributes in relation to treatment application with respect to time. The soils of the irrigated perimeter from Custódia are in the process of degradation and need to have their properties monitored over time to prevent its development. Among the cations evaluated, soluble and exchangeable Na+ was what was in higher concentrations, followed by the Cl- and by the RAS variable, besides increasing the PST in depth. The phytoremediation technique was effective in improving the soils quality and the application of sheep manure and polyacrylamide based polymer also acted positively in improving the quality of soil chemistry and physics.
Na Região Nordeste do Brasil, nas últimas décadas, com o incremento da irrigação em perímetros irrigados, muitas vezes com manejo inadequado às condições locais, os processos de salinização e sodificação de solos têm se intensificado, promovendo a degradação e abandono de extensas áreas anteriormente produtivas. Assim, realizou-se o levantamento da situação de degradação do Perímetro Irrigado de Custódia, no Sertão de Pernambuco, onde foram identificadas áreas com problemas de excesso de sais, seguindo-se de montagem de experimento para recuperação de uma dessas áreas, através da aplicação de compostos orgânicos e químicos, além da técnica da fitorremediação com Atriplex nummularia. Para isso, foram realizadas amostragens de solos em todos os 55 lotes que compõem o perímetro nas profundidades de 0-10, 10-30 e 30-60 cm para a caracterização física e química dos solos, além das análises químicas das águas utilizadas no perímetro nos períodos de Julho/2009, Janeiro/2010, Julho/2010 e Janeiro/2011. Após seleção de área degradada do perímetro, foi montado experimento de recuperação do solo testando-se os tratamentos: 1) plantio de Atriplex nummularia Lindl, 2) aplicação de esterco bovino, 3) esterco ovino, 4) polímero, 5) gesso e 6) controle (testemunha). Foram realizadas quatro amostragens, sendo a primeira no momento da montagem do experimento (Outubro de 2009), aos seis (Abril de 2010), aos doze (Outubro de 2010) e aos dezoito meses (Abril de 2011). As amostras de solo foram coletadas nas camadas de 0-10, 10-30 e 30-60 cm de profundidade para realização das análises químicas. Para a realização das análises físicas do solo coletaram-se amostras de solo na primeira coleta (Outubro de 2009) e na ultima (Abril de 2011) nas profundidades de 0-10 cm e 10-30 cm. Foram monitorados os atributos do solo com a aplicação dos tratamentos em função do tempo. Os solos do Perímetro Irrigado de Custódia encontram-se em processo de degradação e precisam ter suas propriedades monitoradas ao longo do tempo para evitar sua evolução. Entre os cátions avaliados, o Na+ solúvel e trocável foi o que esteve em concentrações mais elevadas, seguido pelo Cl- e pela variável RAS, além do aumento da PST em profundidade. A técnica da fitorremediação foi efetiva na melhoria da qualidade dos solos estudados e a aplicação do esterco ovino e do polímero a base de poliacrilamida também atuaram positivamente na melhoria da qualidade química e física do solo.

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Silva, Alexandre Reuber Almeida da. "Respostas e adaptações de plantas de coqueiro "anão verde" ás interações entre deficiência hídrica e salinidade do solo." reponame:Repositório Institucional da UFC, 2015. http://www.repositorio.ufc.br/handle/riufc/18227.

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SILVA, Alexandre Reuber Almeida da Silva. Respostas e adaptações de plantas de coqueiro "anão verde" ás interações entre deficiência hídrica e salinidade do solo. 2015. 237 f. : Tese (doutorado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola, Fortaleza-CE, 2015.
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In this work morphological, physiological, biochemical and nutritional responses, to elucidate the possible adaptive strategies of young coconut plants, cultivating "Green Dwarf", involved with tolerance to the effects of stress isolated and combined soil salinity and water stress. In the experiment, conducted in a greenhouse, the greenhouse type, in Fortaleza, Ceará, were evaluated under statistical design of randomized blocks in a split plot arrangement, the effects of different levels of water stress by imposing different percentages resets the potential evapotranspiration - ETpc (20; 40; 60; 80 and 100%), related to increasing levels of soil salinity (1.72, 6.25, 25.80 and 40.70 dS m-1) provided by soils derived from the Irrigated Perimeter Morada Nova - PIMN. The effects of treatments on plants were evaluated using the variables: plant height, leaf number, stem diameter, leaf area, biomass production (root, shoot and total), compared root dry biomass of aerial-1, to salinity tolerance indices, leaf gas exchange (stomatal conductance, transpiration, photosynthesis, instant and intrinsic efficiency of water use), quantum yield of chlorophyll fluorescence (Fv Fm-1) level for total chlorophyll (Spad index) , total content of chlorophyll (a + b) and carotenoids, leaf water potential, leaf and root levels of inorganic solutes (potassium ions, sodium and chloride) and organic (total soluble carbohydrates, N - aminossolúveis and free proline) and nutritional state (foliar nutrients of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, copper, manganese and zinc). The growth and biomass production of the plants are sharply reduced by the conditions of water stress and high soil salinity, apparently being more critical to fluid restriction culture. The degree of water stress can enhance the susceptibility to salinity. The physiological mechanisms are effectively limited when water stress and salinity act separately and / or together. The effects of water stress are more effective in the reduction of physiological parameters, to the detriment soil salinity. The magnitudes of physiological responses of plants to water supply and salinity depend on the intensity of stress. Adaptive physiological responses of plants are related mainly to stomatal regulation. In conditions of drought and soil salinity, the plants have linear reductions in the total levels of chlorophyll. Carotenoid levels respond to the combined effects of water availability and soil salinity and reflect the antagonism between them. The coconut has a number of physiological adjustments mechanisms that give the species a partial tolerance to drought stress and / or saline. Saline ions K+, Na+ and Cl- accumulate significantly in young coconut plants, to the detriment of organic solutes, both in the leaves and in the roots, evidencing an apparent root retention ions. Salinity did not change the concentration of organic solutes, however, show up increments in leaf and root levels of free proline in response to water stress. Water stress and soil salinity interact, affecting the nutritional status of plants, except for the nutrient P. Leaf contents of nutrients N, Ca, S, Fe, Mn and Zn grow positively with the increase of water availability and are reduced substantially with increasing salinity. The interaction of smaller water deficit levels with the highest saline levels maximizes the leaf contents of Mg and Cu and minimizes K. During the establishment of coconut seedlings, the need for macronutrients follows the descending order: N, K Ca, Mg, S and P and micronutrients: Fe, Mn, Zn and Cu. The plant nutrition proved to be adequate, except for the imbalances observed in nutrients K, Mg, S and Mn. The coconut seedlings show full capacity of the establishment in saline soils PIMN, corresponding to the level of electrical conductivity to 6.50 dS m-1, but only when the water supply remains adequate. For the higher salinity levels the plants survive, yet the size of the same is reduced by around 50%, even when fully irrigated.
Neste trabalho foram estudadas repostas morfológicas, fisiológicas, bioquímicas e nutricionais, visando elucidar as possíveis estratégias adaptativas de plantas jovens de coqueiro, cultivar “Anão Verde”, envolvidas com sua tolerância aos efeitos dos estresses isolados e/ou combinados, salinidade do solo e deficiência hídrica. No experimento, conduzido em casa de vegetação, do tipo telado, em Fortaleza, Ceará, avaliaram-se, sob delineamento estatístico de blocos casualizados, no arranjo de parcelas subdivididas, os efeitos de diferentes níveis de deficiência hídrica, mediante a imposição de distintos percentuais de reposições da evapotranspiração potencial da cultura - ETpc (20; 40; 60; 80 e 100%), associados à crescentes níveis de salinidade do solo (1,72; 6,25; 25,80 e 40,70 dS m-1), proporcionados pelos solos oriundos do Perímetro Irrigado Morada Nova - PIMN. Os efeitos dos tratamentos sobre as plantas foram avaliados por meio das variáveis: altura de plantas, número de folhas, diâmetro do caule, área foliar, produção de biomassa (radicular, parte aérea e total), relação biomassa seca raiz parte aérea-1, índices de tolerância à salinidade, trocas gasosas foliares (condutância estomática, transpiração, fotossíntese, eficiência instantânea e intrínseca de uso da água), rendimento quântico da fluorescência da clorofila a (Fv Fm-1), teores relativos de clorofila total (índice Spad), teores totais de clorofilas (a+b) e de carotenóides, potencial hídrico foliar, teores foliares e radiculares dos solutos inorgânicos (íons potássio, sódio e cloreto) e orgânicos (carboidratos solúveis totais, N - aminossolúveis e prolina livre) e estado nutricional (teores foliares dos nutrientes nitrogênio, fósforo, potássio, cálcio, magnésio, enxofre, ferro, cobre, manganês e zinco). O crescimento e a produção de biomassa das plantas são acentuadamente reduzidos pelas condições de restrição hídrica e de elevada salinidade do solo, sendo aparentemente mais crítica à cultura a restrição hídrica. O grau de estresse hídrico é capaz de acentuar a suscetibilidade à salinidade. Os mecanismos fisiológicos são efetivamente limitados quando a deficiência hídrica e a salinidade atuam isoladamente e/ou em conjunto. Os efeitos do estresse hídrico se mostram mais efetivos nas reduções dos parâmetros fisiológicos, em detrimento à salinidade do solo. As magnitudes das respostas fisiológicas das plantas ao suprimento hídrico e à salinidade dependem das intensidades do estresses. As respostas fisiológicas adaptativas das plantas estão relacionadas, principalmente, à regulação estomática. Em condições de déficit hídrico e de salinidade do solo, as plantas apresentam reduções lineares nos teores totais de clorofilas. Os teores de carotenóides respondem aos efeitos combinados da disponibilidade hídrica e da salinidade do solo e refletem o antagonismo entre estes. O coqueiro apresenta uma série de mecanismos de ajustes fisiológicos que conferem à espécie uma parcial tolerância ao estresse hídrico e/ou salino. Os íons salinos K+, Na+ e Cl- acumulam-se significativamente em plantas jovens de coqueiro, em detrimento aos solutos orgânicos, tanto nas folhas quanto nas raízes, sendo evidenciada uma aparente retenção radicular de íons. A salinidade não altera os teores dos solutos orgânicos, todavia, denotam-se incrementos nos teores foliares e radiculares de prolina livre em resposta à deficiência hídrica. A deficiência hídrica e a salinidade do solo interagem, afetando o estado nutricional das plantas, excetuando o nutriente P. Os teores foliares dos nutrientes N, Ca, S, Fe, Mn e Zn crescem positivamente com a ampliação da disponibilidade hídrica e reduzem-se substancialmente com o aumento da salinidade. A interação dos menores níveis de deficiência hídrica com os maiores níveis salinos maximiza os teores foliares de Mg e Cu e minimiza os de K. Durante o estabelecimento das plantas jovens de coqueiro, a necessidade de macronutrientes obedece à ordem decrescente: N, K Ca, Mg, S e P e à de micronutrientes: Fe, Mn, Zn e Cu. A nutrição das plantas mostra-se adequada, excetuando-se, os desequilíbrios observados nos nutrientes K, Mg, S e Mn. As plantas jovens de coqueiro mostram plena capacidade de estabelecimento nos solos salinizados do PIMN, até o nível de condutividade elétrica correspondente a 6,50 dS m-1, porém apenas quando o suprimento hídrico se mantém adequado. Para os níveis de salinidade mais elevados as plantas sobrevivem, contudo o porte das mesmas reduz-se em torno de 50%, mesmo quando plenamente irrigadas.

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CARVALHO, José Francisco de. "Dinâmica de sais em cultivo rotacionado com feijão-caupi e milho verde irrigado com água salina." Universidade Federal Rural de Pernambuco, 2013. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5613.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
The process of soil salinization occurs by several factors such as the litolic origin of their training and application of irrigation handled improperly and the use of lower quality water. In the present study it was assessed the effects of irrigation with saline water and fractions of leaching on the dynamics of distribution, uptake by plants and leaving salts of the soil profile as well as interference in crop productivity in cowpea and maize. The study was conducted at the Experimental Station of Irrigated Agriculture Dr. Ronaldo Freire de Moura, in the Department of Rural Technology, Federal Rural University of Pernambuco - UFRPE. The experimental design was completely randomized in a 2x5 factorial arrangement with four replications, applying two levels of salinity and five fractions leaching. It was analyzed: the balance of salts based on the input of fertilizers, irrigation and salts by leaching out and absorbed by crops. Regarding crop it was rated the number of pods per plant, fresh weight of pods, dry pods, weight of 100 grains, length of pods, yield of grain, number of plants per plot, fresh biomass of plants per hectare, fresh shoot biomass plant, dry shoot biomass plant in cowpea crops; number of ears per plot, diameter of ears without straw, straw diameter with ears, fresh straw ear, fresh weight cobs, grain yield hydrated, dehydrated grain yield in maize cultivation; water use efficiency, harvest index for both cowpea and maize. The fractions of leaching 10%, 15% and 20% removed salts from the soil. These was increment on crop variable, when applying 10% leaching fraction, however, the addition of 20% leaching reduced productivity of crops.
O processo de salinização dos solos ocorre por diversos fatores como a origem litólica da sua formação e pela aplicação de irrigações manejadas de forma irregular bem como a utilização de água de qualidade inferior. Na presente pesquisa avaliou-se o efeito da irrigação com água salina e de frações de lixiviação sobre a dinâmica da distribuição, absorção pelas plantas e a saída de sais do perfil do solo, bem como a interferência na produtividade no cultivo de feijão-caupi e milho. O estudo foi realizado na Estação Experimental de Agricultura Irrigada Doutor Ronaldo Freire de Moura, no Departamento de Tecnologia Rural da Universidade Federal Rural de Pernambuco - UFRPE. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 2x5 com quatro repetições, aplicando dois níveis de salinidade e cinco frações de lixiviação. Analisaram-se: o balanço de sais nos fertilizantes, na água de irrigação, no volume lixiviado e no consumo pelas plantas. Com relação aos cultivos, foram avaliados para a cultura do feijão, o número de vagens por planta, massa fresca de vagens, massa seca de vagens, massa de 100 grãos, comprimento de vagens, produtividade de grãos, número de plantas da parcela, biomassa fresca de plantas por hectare, biomassa fresca da parte aérea por planta, biomassa seca da parte aérea por planta; para a cultura do milho, número de espigas por parcela, diâmetro de espigas sem palhas, diâmetro de espigas com palhas, massa fresca de palhas de espigas, massa fresca de sabugos, produtividade de grãos hidratados, produtividade de grãos desidratado; e para ambas culturas, eficiência de uso da água e índice de colheita. As frações de lixiviação de 10%, 15% e 20% proporcionaram retiradas de sais do solo. Houve incremento das variáveis de cultivo quando se aplicou a fração de lixiviação de 10%, entretanto, a adição de lixiviação em 20% reduziu a produtividade dos cultivos.

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ARAÚJO, Rafaela Pereira Souza de. "Identificação de descritores fisiológicos em Jatropha Curcas L. submetida à salinidade." Universidade Federal Rural de Pernambuco, 2016. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/4959.

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One of the consequences of environmental degradation is soil salinization. In this context, it is estimated that in Brazil, of the 4.5 million hectares that are compromised by salinization, most located in the northeastern semi-arid region. A strategy to recover these degraded areas would be the insertion and proper handling of plant species such as Jatropha. Keeping in view the potential Jatropha, this study aimed to evaluate the physiological responses of seeds and Jatropha curcas L. seedlings subjected to salt stress. Two tests were performed at the Federal Rural University of Pernambuco, using seeds provided by Embrapa Agroenergy. In the test I the seeds were put in germistest paper and moistened with solutions 0, 50, 75 and 100 mM NaCl and placed in germinator. We evaluated the germination percentage, germination speed index, average germination time, shoot length, root and totality, fresh and dry weight of shoot, root and analysis of organic solutes. Already for the test II after germination in washed sand, plantlets were transferred to vessels containing 12 kg of washed sand. During the acclimation period they were watered with nutrient solution ½ strength Hoagland and Arnon and water. The experimental design was composed by the imposition of the same salt solutions than those used in the test I and two evaluation periods (15 and 30 days after differentiation of treatments). We analyzed the growth, gas exchange, water relations, the content of photosynthetic pigments and organic solutes. A reduction in the emergency speed index, initial growth and carbohydrates and proline of the jatropha root. The average time of germination is increased and also the organic solutes present in the shoot at the level of 75 mM NaCl. Salinity affects the germination performance of Jatropha seeds. In general, the variables related to growth, decreased from the level of 50 mM NaCl after 15 and 30 days of salt stress. Regarding gas exchange, Stomatal closure was was observed for the same level of salinity, being more pronounced in seedlings subjected to treatments of 75 and 100 mM NaCl, from 15 days of salt stress. For water relations, there are reductions in the TRA with increasing salinity in the two times of evaluation (4 and 12h). Similarly, after 30 days of salt stress, it was found reductions in photosynthetic pigments and chlorophyll content in all evaluated saline treatments. Regarding organic solutes, the levels of carbohydrates and amino acids in the leaves and roots were affected by salinity mainly in the levels of 75 and 100 mM NaCl, since proline was not indicative of stress for the species under study. Jatropha plants when subjected to salinity up to 100 mM NaCl has committed its initial development, but the species does not paralyze their growth.
Uma das consequências resultantes do processo de degradação ambiental é a salinização do solo. Nesse contexto, estima-se que no Brasil, dos 4,5 milhões de hectares que estejam comprometidos pela salinização, a maioria localiza-se na região do semiárido nordestino. Uma estratégia para recuperação dessas áreas degradadas seria a inserção e manejo adequado de espécies vegetais, tais como o pinhão manso. Tendo em vista as potencialidades do pinhão manso, a presente pesquisa objetivou avaliar as respostas fisiológicas em sementes e mudas de Jatropha curcas L. submetidas ao estresse salino. Dois ensaios foram realizados na Universidade Federal Rural de Pernambuco, utilizando sementes fornecidas pela Embrapa Agroenergia. No ensaio I as sementes foram postas em papel germistest e umedecida com soluções de 0, 50, 75 e 100 mM de NaCl e acondicionadas em germinador. Avaliou-se a porcentagem de germinação, índice de velocidade de germinação, tempo médio de germinação, comprimento da parte aérea, da raiz e total, matéria fresca e seca da parte aérea, raiz e análises dos solutos orgânicos. Já para o ensaio II, após a germinação em areia lavada, as plântulas foram transferidas para vasos contendo 12 Kg de areia lavada. Durante o período de aclimatação estas foram regadas com solução nutritiva a ½ força de Hoagland e Arnon e com água. O delineamento experimental foi composto pela imposição das mesmas soluções salinas que as utilizadas no ensaio I e dois períodos de avaliação (15 e 30 dias após a diferenciação dos tratamentos). Analisou-se o crescimento, as trocas gasosas, as relações hídricas, os teores de pigmentos fotossintéticos e os solutos orgânicos. Verificou-se redução no índice de velocidade de emergência, no crescimento inicial e nos carboidratos e prolina da raiz de pinhão manso. Já o tempo médio de germinação é aumentado e também os solutos orgânicos presentes na parte aérea no nível de 75 mM de NaCl. A salinidade compromete o desempenho germinativo de sementes de pinhão manso. De forma geral, as variáveis relacionadas ao crescimento, apresentaram redução a partir do nível de 50 mM de NaCl após 15 e 30 dias de estresse salino. Em relação às trocas gasosas, o fechamento estomático foi constatado para este mesmo nível de salinidade, sendo mais acentuado nas mudas submetidas aos tratamentos de 75 e 100 mM de NaCl, a partir de 15 dias de estresse salino. Para as relações hídricas, verificam-se reduções no TRA com o aumento da salinidade nos dois horários de avaliação (4 e 12h). Da mesma forma, após 30 dias de estresse salino, constatouse reduções nos pigmentos fotossintéticos e no índice de clorofila em todos os tratamentos salinos avaliados. Com relação aos solutos orgânicos, os teores de carboidratos e aminoácidos nas folhas e raízes foram afetados pela salinidade principalmente nos níveis de 75 e 100 mM de NaCl, já a prolina não foi um indicativo de estresse para a espécie em estudo. Plantas de pinhão manso quando submetidas à salinidade de até 100 mM de NaCl tem seu desenvolvimento inicial comprometido, entretanto a referida espécie não paralisa seu crescimento.

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26

Speldewinde, Peter Christiaan. "Ecosystem health : the relationship between dryland salinity and human health." University of Western Australia. School of Population Health, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0127.

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Australia is experiencing widespread ecosystem degradation, including dryland salinity, erosion and vegetation loss. Approximately 1 million hectares (5.5%) of the south-west agricultural zone of Western Australia is affected by dryland salinity and is predicted to rise to 5.4 million hectares by 2050. Such degradation is associated with many environmental outcomes that may impact on human health, including a decrease in primary productivity, an increase in the number of invasive species, a decrease in the number of large trees, overall decrease in biodiversity, and an increase in dust production. The resulting degradation affects not only farm production but also farm values. This study examines the effects of such severe and widespread environmental degradation on the physical and mental health of residents. Western Australia has an extensive medical record database which links individual health records for all hospital admissions, cancer cases, births and deaths. For the 15 diseases examined in this project, the study area of the south west of Western Australia (excluding the capital city of Perth) contained 1,570,985 morbidity records and 27,627 mortality records for the 15 diseases examined in a population of approximately 460,000. Environmental data were obtained from the Western Australian Department of Agriculture?s soil and landscape mapping database. A spatial Bayesian framework was used to examine associations between these disease and environmental variables. The Bayesian model detected the confounding variables of socio-economic status and proportion of the population identified as Aboriginal or Torres Strait Islander. With the inclusion of these confounders in the model, associations were found between environmental degradation (including dryland salinity) and several diseases with known environmentally-mediated triggers, including asthma, ischaemic heart disease, suicide and depression. However, once records of individuals who had been diagnosed with coexistent depression were removed from the analysis, the effect of dryland salinity was no longer statistically detectable for asthma, ischaemic heart disease or suicide, although the effects of socio-economic status and size of the Aboriginal population remained. The spatial component of this study showed an association between land degradation and human health. These results indicated that such processes are driving the degree of psychological ill-health in these populations, although it remains uncertain whether this 4 is secondary to overall coexisting rural poverty or some other environmental mechanism. To further investigate this complex issue an instrument designed to measure mental health problems in rural communities was developed. Components of the survey included possible triggers for mental health, including environmental factors. The interview was administered in a pilot study through a telephone survey of a small number of farmers in South-Western Australia. Using logistic regression a significant association between the mental health of male farmers and dryland salinity was detected. However, the sample size of the survey was too small to detect any statistically significant associations between dryland salinity and the mental health of women. The results of this study indicate that dryland salinity, as with other examples of ecosystem degradation, is associated with an increased burden of human disease.

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27

Horsnell, Tara Kathleen. "Quantifying thresholds for native vegetation to salinity and waterlogging for the design of direct conservation approaches." University of Western Australia. School of Environmental Systems Engineering, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0082.

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A field-based project was undertaken to develop and test a mechanism which would allow for the correlation of the health of vegetation surrounding playa lakes in south-west Australia with the natural variation in salinity and waterlogging that occurs spatially and temporally in natural systems. The study was designed to determine threshold ranges of vegetation communities using moderately extensive data over short temporal periods which will guide the design of potential engineering solutions that manipulate hydrological regimes to ultimately conserve and protect native vegetation. A pair of playa lake ecosystems, surrounded by primary production land, was modelled with hydro-geological data collected from March 2006 to March 2007. The data was used to determine the hydroperiods of vegetation communities fringing playa lakes and provide insight into the areas and species that are most affected by extreme rainfall events which are hypothesised to have a significant, rapid deleterious effect on the ecosystems. The methodology was multi-faceted and included; a detailed topographical survey; vegetation surveys; hydrological and hydro-geological monitoring over a 12 month period. 4 The hydro-geological data and vegetation data was linked with the topographical survey at a high resolution for spatial analysis in a Geographic Information System (GIS) to determine the degree of waterlogging experienced by vegetation communities over the monitoring period. The study has found that the spatial and temporal variability of hydroperiods has been reduced by rising groundwater levels, a result of extensive clearing of native vegetation. Consequently populations are becoming extinct locally resulting in a shift in community composition. Extreme summer rainfall events also have a significant impact on the health of vegetation communities by increasing the duration of waterlogging over an annual cycle and in some areas expanding the littoral zone. Vegetation is most degraded at lower positions in the landscape where communities are becoming less diverse and dominated by salt tolerant halophytic species as a result of altered hydrological regimes. Some species appear to be able to tolerate groundwater depths of less than 2.0 m from the surface, however there are thresholds related to the duration at which groundwater is maintained at this depth. Potential engineering solutions include groundwater pumping and diverting water through drains to maintain sustainable hydroperiods for vegetation in areas with conservation value. The effectiveness and efficiency of the engineering solutions can be maximised by quantifying thresholds for vegetation that include sustainable durations of waterlogging. The study has quantified tolerance ranges to salinity and waterlogging with data collected over 12 months but species may be experiencing a transition period where they have 5 sustained irreversible damage that will result in their eventual mortality. With long-term monitoring, the methodology developed and tested in the study can be used to quantify the long-term tolerance ranges that are important for the application of conservation approaches that include engineering solutions.

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Slezák, Jakub. "Sledování vlivu simulované intenzity deště na zeminu zatíženou splachovými vodami metodou EIS." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227450.

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The diploma thesis with name “Monitoring the Impact of Simulated Rainfall on Soil with Flushing Water by EIS Method” deals with the problems of soil degradation due to salinization and sodification in consequence of infiltration of flushing waters from roads during winter maintenance. This experiment was realized in laboratories of the Institute of water structures of the Faculty of Civil engineering at Brno University of Technology and researched the influence of simulated rainfall on degraded soil by method of electrical impedance spectrometry (EIS). The thesis follows the solution of projects in international EUREKA program.

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Mashimbye, Zama Eric. "Remote sensing-based identification and mapping of salinised irrigated land between Upington and Keimoes along the lower Orange River, South Africa." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1647.

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Jardine, Andrew. "The impact of dryland salinity on Ross River virus in south-western Australia : an ecosystem health perspective." University of Western Australia. School of Population Health, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0182.

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[Truncated abstract] A functional ecosystem is increasingly being recognised as a requirement for health and well being of resident human populations. Clearing of native vegetation for agriculture has left 1.047 million hectares of south-west Western Australia affected by a severe form of environmental degradation, dryland salinity, characterised by secondary soil salinisation and waterlogging. This area may expand by a further 1.7-3.4 million hectares if current trends continue. Ecosystems in saline affected regions display many of the classic characteristics of Ecosystem Distress Syndrome (EDS). One outcome of EDS that has not yet been investigated in relation to dryland salinity is adverse human health implications. This thesis focuses on one such potential adverse health outcome: increased incidence of Ross River virus (RRV), the most common mosquito-borne disease in Australia. Spatial analysis of RRV notifications did not reveal a significant association with dryland salinity. To overcome inherent limitations with notification data, serological RRV antibody prevalence was also investigated, and again no significant association with dryland salinity was detected. However, the spatial scale imposed limited the sensitivity of both studies. ... This thesis represents the first attempt to prospectively investigate the influence of secondary soil salinity on mosquito-borne disease by combining entomological, environmental and epidemiological data. The evidence collected indicates that RRV disease incidence is not currently a significant population health priority in areas affected by dryland salinity despite the dominant presence of Ae. camptorhynchus. Potential limiting factors include; local climatic impact on the seasonal mosquito population dynamics; vertebrate host distribution and feeding behaviour of Ae. camptorhynchus; and the scarce and uneven human population distribution across the region. However, the potential for increased disease risk in dryland salinity affected areas to become apparent in the future cannot be discounted, particularly in light of the increasing extent predicted to develop over coming decades before any benefits of amelioration strategies are observed. Finally, it is important to note that both dryland salinity and salinity induced by irrigation are important forms of environmental degradation in arid and semi-arid worldwide, with a total population of over 400 million people. Potential health risks will of course vary widely across different regions depending on a range of factors specific to the local region and the complex interactions between them. It is therefore not possible to make broad generalisations. The need is highlighted for similar research in other regions and it is contended that an ecosystem health framework provides the necessary basis for such investigations.

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Silva, Rafael Cipriano da. "GÃnese e classificaÃÃo de solos em ambientes de planÃcies da regiÃo Nordeste do Brasil." Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8512.

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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior
Solos formados por sedimentos em ambientes de planÃcie apresentam caracterÃsticas genÃticas distintas quanto ao material de origem, podendo ser compostos basicamente por sedimentos minerais e orgÃnicos. O primeiro Ã formado a partir do intemperismo das rochas, e as propriedades quÃmicas, fÃsicas e mineralÃgicas sÃo herdadas do material que lhe deram origem. JÃ os sedimentos orgÃnicos sÃo influenciados pelo tipo de vegetaÃÃo predominante na paisagem, e o aporte de material orgÃnico em condiÃÃo de saturaÃÃo de Ãgua, que favorece o acÃmulo e o espessamento das camadas de sedimentos orgÃnicos, podendo levar Ã gÃnese dos solos orgÃnicos. Este estudo teve por objetivo avaliar as caracterÃsticas morfolÃgicas, fÃsicas e quÃmicas de seis perfis de solos orgÃnicos desenvolvidos na regiÃo litorÃnea dos Estados do CearÃ, Rio Grande do Norte e ParaÃba; e avaliar os mesmos atributos e as caracterÃsticas mineralÃgicas e micromorfolÃgicas de quatro perfis de solos originados de sedimentos aluviais do baixo curso da Bacia do rio AcaraÃ - CE. Foram avaliadas propriedades tais como: cor, densidade, textura, teores de fibras, grau de decomposiÃÃo da matÃria orgÃnica, teores de C, matÃria orgÃnica, N, P e micronutrientes, soma de bases, valor T e V, fraÃÃes hÃmicas, grau de repelÃncia Ã Ãgua, condutividade elÃtrica, sais solÃveis, difratometria de raio-X, dentre outras. Para os Organossolos, foi verificado que os teores de C estabeleceram correlaÃÃes positivas com a densidade do solo, com a subsidÃncia, acidez potencial, com os teores de N e com a hidrofobicidade, alÃm de influenciar na CTC e no teor de H+ proveniente dos Ãcidos orgÃnicos. Os diferentes mÃtodos para a determinaÃÃo dos teores de carbono orgÃnico apresentaram correlaÃÃo positiva entre si. Os teores de C da fraÃÃo humina foram mais elevados devido Ã presenÃa de fibras nesta fraÃÃo, enquanto que os teores de Ãcidos fÃlvicos foram os menores em relaÃÃo aos teores de Ãcidos hÃmicos, indicando maior estabilidade dos compostos orgÃnicos presentes nestes solos. Com relaÃÃo aos solos de sedimentos aluviais, foram observados elevados teores de sais solÃveis, conferindo-lhes carÃter salino e sÃdico. Isso se deve Ã influÃncia marinha e do lenÃol freÃtico elevado, alÃm da presenÃa de minerais intemperizÃveis. Na descriÃÃo micromorfolÃgica foram verificados alguns aspectos relacionados Ã gÃnese desses solos, tais como a iluviaÃÃo de argila em profundidade, a origem alÃctone do material de origem e a alteraÃÃo in situ desses sedimentos aluviais. A geomorfologia foi o principal fator na maior expressÃo dos processos pedogenÃticos na paisagem, e a posiÃÃo em que os solos se encontram Ã um forte indicativo de sua fragilidade ambiental.
Soils formed by sediments in lowland environments have distinct genetic characteristics according to the parent material, which can be basically composed of mineral and organic sediments. The first is formed from the weathering of rocks, and the chemical, physical and mineralogical properties are inherited from the source material. The organic sediments are influenced by the type of vegetation dominant in the landscape, and the addition of organic material under water saturation conditions, that favors the accumulation and thickening of organic sediment layers, which can lead to the genesis of organic soils. This study aimed to evaluate the morphological, physical and chemical properties of six organic soil profiles developed in the coastal region of the States of CearÃ, Rio Grande do Norte and ParaÃba; besides these attributes and the mineralogical and micromorphological characteristics of four soil profiles from alluvial sediments in the lower course of AcaraÃ river Basin - CE. The properties evaluated were: color, density, texture, fiber content, degree of decomposition of organic matter, C content, organic matter, N, P and micronutrients, sum of bases, T and V value, humic fractions, degree of water repellency, electrical conductivity, soluble salts, X-ray diffraction, among others. For the Histosols, it was found a positive correlation of the C levels with the soil density, with subsidence, potential acidity, N content and hydrophobicity; as well as influencing the CTC and the content of H+ from the organic acids. The different methods for measuring organic carbon were positively correlated with each other. The C content of humin fraction were higher due to the presence of fibers in this fraction, while the fulvic acid contents were lower compared to the humic acids, indicating increased stability of organic compounds present in these soils. With respect to the soils from alluvial sediments, there were observed high levels of soluble salts, conferring them the saline and sodic characters. This is due to the marine influence and the high water table, besides the presence of weatherable minerals. The micromorphological description showed some aspects related to the soil genesis, such as clay illuviation in depth, the allochthonous origin of the parent material and in situ alteration of the alluvial sediments. The geomorphology was the main factor in the greatest expression of pedogenetic processes in the landscape, and the position where the soils are located is a strong indicator of their environmental fragility.

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32

Lerotholi, Sekhonyana. "The role of salinity as an abiotic driver of ecological condition in a rural agricultural catchment." Thesis, Rhodes University, 2006. http://hdl.handle.net/10962/d1005528.

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The Kat River is an agricultural catchment that drains salt rich geology. Potential salinity impacts on ecological condition of the river were investigated. Monthly salt concentrations and flow discharges were monitored at ten sites along the Kat River below the Kat Dam. Monthly salt loads were computed to relate salinity to land use and ionic data used to assess the toxicity of major salts using the TIMS model. Concentration duration curves for sodium chloride were derived from flow concentration relationships, representing sodium chloride concentrations to which the aquatic ecosystem had been exposed. The ecological condition was assessed at nineteen sites using SASS5 biotic index over four seasons. Finally, the modelled instream salt concentrations and bioasessments were evaluated in terms of the modelled level of species protection afforded at different salt concentrations. Species Sensitivity Distributions (SSDs) were used for this exercise. There was a general downstream increase in salinity with the minimum concentrations recorded at the Fairbain tributary (84 mg/L) and maximum levels at the sewage outfall in Fort Beaufort (1222 mg/L). There was evidence that citrus irrigation upstream of Fort Beaufort increased salinisation. Sodium chloride, and to a lesser extent magnesium sulphate, were the dominant salts in the Kat River catchment, with the latter being more toxic. However these had little or no impact on the aquatic ecosystem. Flow-derived sodium chloride concentrations showed that both the Balfour and Blinkwater tributaries were in a fair/ poor condition. However with regard to ecological condition, it was demonstrated that the river is generally in a good state except for the Blinkwater River and the lower catchment. Degraded habitat condition at the Blinkwater was responsible for poor ecological condition. Integrating SSD derived classes, sodium chloride classes and ecological condition indicated that sodium chloride is a driver of ecological condition at the sewage treatment works and the subsequent site (only two of nineteen biomonitoring sites).

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33

Duarte, Gabriel Alexandre Isidoro. "Soil salinization as a stress factor for soil fauna." Master's thesis, 2011. http://hdl.handle.net/10316/30829.

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Dissertação de Mestrado em Ecologia, apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra.
A existência de condições desfavoráveis no solo (p.e. um agente químico) pode influenciar a presença de organismos de solo ou parâmetros do ciclo de vida tais como a reprodução da fauna do solo num local específico. Logo, a resposta de evitamento e o sucesso reprodutivo de organismos em locais contaminados pode ser utilizada como uma primeira ferramenta de avaliação de risco ecológico, já que respostas negativas de evitamento ou reprodução significam que deverá haver algum contaminante no solo testado. Neste trabalho abordou-se o problema da salinização dos solos, numa tentativa de avaliar o stress causado pela mesma nos invertebrados de solo, e o seu efeito conjunto com diferentes percentagens de matéria orgânica no solo, assim como com um pesticida frequentemente utilizado (lambda-cyalotrina). O objectivo final deste projecto era desenvolver modelos utilizando Modelação Linear Generalizada (GLM) que permitam prever valores de evitamento e reprodução quando um solo está contaminado com NaCl, e no caso específico de se encontrar também contaminado com o pesticida utilizado. Para alcançar o objectivo utilizaram-se três espécies de invertebrados de solo nos testes: Eisenia andrei, Folsomia candida e Enchytraeus crypticus. Folsomia candida e Eisenia andrei foram utilizados para os testes de evitamento, enquanto que para os testes de reprodução foram utilizados Folsomia candida e Enchytraeus crypticus. Os resultados obtidos pelos testes mostram uma efeito negativo claro da salinidade quer na resposta de evitamento quer na reprodução, e uma influência negatica do pesticida na reprodução de Folsomia candida. Os modelos obtidos explicam a maior parte da variável de resposta e podem vir a ser ferramentas robustas para prever valores de reprodução e evitamento em solos salinos.
The existence of unfavorable conditions in soil (e.g. a chemical stressor) may influence the presence of soil organisms or life cycle parameters such as reproduction of soil fauna in a particular site. Therefore avoidance response and reproductive output of organisms to contaminated sites can be used as an early screening assessment of ecological risk, since a negative response on avoidance or reproduction means that there must be some contaminant in the tested soil. In this work the problem of soil salinization is addressed, in an attempt to evaluate the stress caused by soil salinization to soil invertebrates, and its combined effect with different organic matter percentages in the soil and also with a commonly used pesticide (lambda-cyalothrin). The final goal of this project was to develop predictive models using Generalized Linear Modeling (GLMs) that would allow to calculate a predicted value for avoidance response and reproductive output when a soil is contaminated with NaCl, and in the specific case of contamination by both NaCl and the pesticide. To achieve this, three species of soil invertebrates were used in the tests: Eisenia andrei, Folsomia candida and Enchytraeus crypticus. Folsomia candida and Eisenia andrei were used for the avoidance tests while for the reproduction tests Folsomia candida and Enchytraeus crypticus were selected. The results provided by the tests show a clear negative effect of salinity in both avoidance behavior and reproduction output, and a negative influence of the pesticide in the reproduction of Folsomia candida. The GLM models obtained explain most of the response variability and can become powerful tools for predicting avoidance and reproduction values in a saline soil.

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34

葉昕祐. "A study in salinization of soil in Kouhu region, Yunlin." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/24461903288223684867.

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35

"GmSAL1 enhances vacuolar sodium ion compartmentalization and ROS scavenging in a calcium dependent manner." 2008. http://library.cuhk.edu.hk/record=b5893427.

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Abstract:

Koo, Siu Chung Nicolas.
Thesis submitted in: November 2007.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2008.
Includes bibliographical references (leaves 78-86).
Abstracts in English and Chinese.
Thesis committee --- p.i
Statement --- p.ii
Abstract --- p.iii
Chinese Abstract --- p.v
Acknowledgements --- p.vi
Abbreviations --- p.viii
Table of contents --- p.xi
List of figures --- p.xv
List of tables --- p.xvii
Chapter 1. --- General Introduction
Chapter 1.1 --- General introduction to salt tolerance in plant --- p.1
Chapter 1.1.1 --- Adverse effecst of high salinity in plant cells
Chapter 1.1.1.1 --- Ion toxicity --- p.1
Chapter 1.1.1.2 --- Disturbed osmotic homeostasis --- p.2
Chapter 1.1.1.3 --- Oxidative stress --- p.3
Chapter 1.1.2 --- Major salt tolerance strategy in plant
Chapter 1.1.2.1 --- Maintenance of ion homeostasis --- p.4
Chapter 1.1.2.2 --- Maintaining osmotic homeostasis --- p.4
Chapter 1.1.2.3 --- Detoxification of Reactive oxygen species --- p.4
Chapter 1.2 --- Cytosolic Calcium signal in plant
Chapter 1.2.1 --- General introduction of calcium in plant --- p.6
Chapter 1.2.2 --- Calcium transport in plant cell --- p.7
Chapter 1.2.3 --- Cytosolic calcium signals in plant under abiotic stress --- p.9
Chapter 1.2.4 --- Responding to cytosolic calcium signals --- p.12
Chapter 1.3 --- Calcium mediated ion homeostasis in plant under salt stress
Chapter 1.3.1 --- General introduction on Calcium dependent ion channels in plant --- p.13
Chapter 1.3.2 --- SOS family cascade in Arabidopsis --- p.13
Chapter 1.4 --- The interaction between cytosolic calcium and reactive oxygen species in plants --- p.14
Chapter 1.5 --- "Calcium signaling mediated by Inositol 1,4,5 triphosphate in plant" --- p.15
Chapter 1.6 --- Study on HAL2 and its homolog in plant --- p.18
Chapter 1.7 --- Previous studies on GmSAL1 in Prof. Lam's lab --- p.20
Chapter 1.8 --- Hypothesis and significant of this project --- p.21
Chapter 2 --- Materials and Methods
Chapter 2.1 --- Materials
Chapter 2.1.1 --- "Plants, bacterial strains and vectors" --- p.23
Chapter 2.1.2 --- Chemicals and Regents --- p.25
Chapter 2.1.3 --- Commercial kits --- p.26
Chapter 2.1.4 --- Primers and Adaptors --- p.27
Chapter 2.1.5 --- Equipments and facilities used --- p.27
Chapter 2.1.6 --- "Buffer, solution, gel and medium" --- p.27
Chapter 2.1.7 --- Software --- p.28
Chapter 2.2 --- Methods
Chapter 2.2.1 --- Molecular Techniques
Chapter 2.2.1.1 --- Bacterial cultures for recombinant DNA and plant transformation --- p.29
Chapter 2.2.1.2 --- Recombinant DNA techniques --- p.29
Chapter 2.2.1.3 --- Preparation and transformation of Agrobacterium competent cells --- p.30
Chapter 2.2.1.4 --- Gel electrophoresis --- p.31
Chapter 2.2.1.5 --- DNA and RNA extractions --- p.32
Chapter 2.2.1.6 --- Generation of single-stranded DIG-labeled PCR probes --- p.34
Chapter 2.2.1.7 --- Testing the concentration of DIG-labeled probes --- p.36
Chapter 2.2.1.8 --- Northern blot analysis --- p.36
Chapter 2.2.1.9 --- PCR techniques --- p.37
Chapter 2.2.1.10 --- Sequencing --- p.38
Chapter 2.2.2 --- Plant cell culture and transformation
Chapter 2.2.2.1 --- Arabidopsis thaliana --- p.39
Chapter 2.2.2.2 --- Nicotiana tabacum L. cv. Bright Yellow 2 (BY-2) cells --- p.39
Chapter 2.2.3 --- Growth and treatment conditions for plants
Chapter 2.2.3.1 --- Growth and salt treatment condition of soybean samples for gene expression studies of GmSAL1 --- p.40
Chapter 2.2.3.2 --- Root assay of GmSAL1l transgenic Arabidopsis thaliana --- p.41
Chapter 2.2.4 --- "Cell viability, ROS detection and confocal microscopy"
Chapter 2.2.4.1 --- Cell viability assay --- p.42
Chapter 2.2.4.2 --- Detection of intracellular contents of Na+ --- p.42
Chapter 2.2.4.3 --- Detection of Reactive oxygen species (ROS) --- p.42
Chapter 2.2.4.4 --- Confocal microscopy --- p.43
Chapter 2.2.4.5 --- Images processing and analysis --- p.43
Chapter 2.2.5 --- Statistical analysis --- p.44
Chapter 3 --- Results
Chapter 3.1 --- GmSAL1 sequence analysis --- p.45
Chapter 3.2 --- Expression of GmSAL1 was induced by NaCl stress --- p.49
Chapter 3.3 --- Construction of GmSAL1 transgenic tobacco BY-2 cell line --- p.50
Chapter 3.4 --- Ectopic expression of GmSAL1 alleviates NaCl stress in transgenic tobacco BY-2 cells --- p.52
Chapter 3.5 --- GmSAL1 enhances vacuolar sodium compartmentalization in transgenic tobacco BY-2 cell under NaCl treatment --- p.55
Chapter 3.6 --- GmSAL1 helps maintain cell turgidity in transgenic tobacco BY-2 cell under NaCl treatment --- p.58
Chapter 3.7 --- GmSAL1 enhances ROS scavenging in transgenic tobacco BY-2 cell under NaCl treatment --- p.61
Chapter 3.8 --- Effect of expressing GmSAL1 in Arabidopsis thaliana under salt stress --- p.64
Chapter 4 --- Discussion --- p.66
Chapter 4.1 --- Sequence analysis and enzyme activity of GmSAL1 --- p.68
Chapter 4.2 --- Gene expression profile of GmSAL1 --- p.70
Chapter 4.3 --- Functional analysis of GmSAL1 in transgenic tobacco BY-2 cells
Chapter 4.3.1 --- GmSAL1 protects transgenic BY-2 cells under salt treatment --- p.71
Chapter 4.3.2 --- GmSAL1 regulates Na+ compartmentalization and ROS scavenging in transgenic BY-2 cells under NaCl treatment in a calcium dependent manner --- p.72
Chapter 4.4 --- Functional tests of GmSAL1 transgenic A. thaliana --- p.75
Chapter 5 --- Conclusion and perspective --- p.76
References --- p.78
"Appendix I: Substrate specificity and Km, Kcat values of GmSAL1 protein" --- p.87
Appendix II: Restriction and modifying enzymes --- p.89
Appendix II: Chemicals --- p.90
Appendix III: Commercial kits --- p.94
Appendix IV: Equipments and facilities used --- p.95
"Appendix V: Buffer, solution, gel and medium formulation" --- p.96

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36

Dutkiewicz, Anna. "Evaluating hyperspectral imagery for mapping the surface symptoms of dryland salinity." Thesis, 2006. http://hdl.handle.net/2440/37813.

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Abstract:

Airborne hyperspectral imagery has the potential to overcome the spectral and spatial resolution limitations of multispectral satellite imagery for monitoring salinity at both regional and farm scales. In particular, saline areas that have good cover of salt tolerant plants are difficult to map with multispectral satellite imagery. Hyperspectral imagery may provide a more reliable salinity mapping method because of its potential to discriminate halophytic plant cover from non - halophytes. HyMap and CASI airborne imagery ( at 3m ground resolution ) and Hyperion satellite imagery ( at 30 resolution ) were acquired over a 140 sq km dryland agricultural area in South Australia, which exhibits severe symptoms of salinity, including extensive patches of the perennial halophytic shrub samphire ( Halosarcia pergranulata ), sea barley grass ( Hordeum marinum ) and salt encrusted pans. The HyMap and Hyperion imagery were acquired in the dry season ( March and February respectively ) to maximise soil and perennial vegetation mapping. The optimum time of year to map sea barley grass, an annual species, was investigated through spectral discrimination analysis. Multiple reflectance spectra were collected of sea barley grass and other annual grasses with an ASD Fieldspec Pro spectrometer during the September spring flush and in November during late senescence. Comparing spectra of different species in November attempted to capture the spectral differences between the late senescing sea barley grass and other annual grasses. Broad NIR and SWIR regions were identified where sea barley grass differs significantly from other species in November during late senescence. The sea barley grass was therefore shown to have the potential to be discriminated and mapped with hyperspectral imagery at this time and as a result the CASI survey was commission for November. Other salinity symptoms were characterised by collecting single field and laboratory spectra for comparison to image derived spectra in order to provide certainty about the landscape components that were to be mapped. Endmembers spectra associated with saltpans and samphire patches were extracted from the imagery using automated endmember generation procedures or selected regions of interest and used in subsequent partial unmixing. Spectral subsets were evaluated for their ability to optimise salinity maps. The saltpan spectra contained absorption features consistent with montmorillonite and gypsum. A single gypsum endmember from one image strip successfully mapped saltpans across multiple images strips using the 1750 nm absorption feature as the input to matched filter unmixing. The individual spectra of green and red samphire are dominated by photosynthetic vegetation characteristics. The spectra of green samphire, often seen with red tips, exhibit peaks in both green and red wavebands whereas the red samphire spectra only contain a significant reflectance peak in the visible red wavelength region. For samphire, Mixture Tuned Matched Filtering using image spectra, containing all wavelength regions, from known samphire patches produced the most satisfactory mapping. Output salinity maps were validated at over 100 random sites. The HyMap salinity maps produced the most accurate results compared to CASI and Hyperion. HyMap successfully mapped highly saline areas with a good cover of samphire vegetation at Point Sturt without the use of multitemporal imagery or ancillary data such as topography or PIRSA soil attribute maps. CASI and Hyperion successfully mapped saltpan, however, their samphire maps showed a poor agreement with field data. These results suggest that perennial vegetation mapping requires all three visible, NIR and SWIR wavelength regions because the SWIR region contains important spectral properties related to halophytic adaptations. Furthermore, the unconvincing results of the CASI sea barley grass maps suggests that the optimal sensor for mapping both soil and vegetation salinity symptoms are airborne sensors with high spatial and spectral resolution, that incorporate the 450 to 1450 nm wavelength range, such as HyMap. This study has demonstrated that readily available software and image analysis techniques are capable of mapping indicators of varying levels of salinity. With the ability to map symptoms across multiple image strips, airborne hyperspectral imagery has the potential for mapping larger areas covering sizeable dryland agriculture catchments, closer in extent to single satellite images. This study has illustrated the advantage of the hyperspectral imagery over traditional soil mapping based on aerial photography interpretation such as the NLWRA Salinity 2000 and the PIRSA soil landscape unit maps. The HyMap salinity maps not only improved mapping of saline areas covered with samphire but also provided salinity maps that varied spatially within saline polygons.
Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2006.

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37

Dutkiewicz, Anna. "Evaluating hyperspectral imagery for mapping the surface symptoms of dryland salinity." 2006. http://hdl.handle.net/2440/37813.

Full text

Abstract:

Airborne hyperspectral imagery has the potential to overcome the spectral and spatial resolution limitations of multispectral satellite imagery for monitoring salinity at both regional and farm scales. In particular, saline areas that have good cover of salt tolerant plants are difficult to map with multispectral satellite imagery. Hyperspectral imagery may provide a more reliable salinity mapping method because of its potential to discriminate halophytic plant cover from non - halophytes. HyMap and CASI airborne imagery ( at 3m ground resolution ) and Hyperion satellite imagery ( at 30 resolution ) were acquired over a 140 sq km dryland agricultural area in South Australia, which exhibits severe symptoms of salinity, including extensive patches of the perennial halophytic shrub samphire ( Halosarcia pergranulata ), sea barley grass ( Hordeum marinum ) and salt encrusted pans. The HyMap and Hyperion imagery were acquired in the dry season ( March and February respectively ) to maximise soil and perennial vegetation mapping. The optimum time of year to map sea barley grass, an annual species, was investigated through spectral discrimination analysis. Multiple reflectance spectra were collected of sea barley grass and other annual grasses with an ASD Fieldspec Pro spectrometer during the September spring flush and in November during late senescence. Comparing spectra of different species in November attempted to capture the spectral differences between the late senescing sea barley grass and other annual grasses. Broad NIR and SWIR regions were identified where sea barley grass differs significantly from other species in November during late senescence. The sea barley grass was therefore shown to have the potential to be discriminated and mapped with hyperspectral imagery at this time and as a result the CASI survey was commission for November. Other salinity symptoms were characterised by collecting single field and laboratory spectra for comparison to image derived spectra in order to provide certainty about the landscape components that were to be mapped. Endmembers spectra associated with saltpans and samphire patches were extracted from the imagery using automated endmember generation procedures or selected regions of interest and used in subsequent partial unmixing. Spectral subsets were evaluated for their ability to optimise salinity maps. The saltpan spectra contained absorption features consistent with montmorillonite and gypsum. A single gypsum endmember from one image strip successfully mapped saltpans across multiple images strips using the 1750 nm absorption feature as the input to matched filter unmixing. The individual spectra of green and red samphire are dominated by photosynthetic vegetation characteristics. The spectra of green samphire, often seen with red tips, exhibit peaks in both green and red wavebands whereas the red samphire spectra only contain a significant reflectance peak in the visible red wavelength region. For samphire, Mixture Tuned Matched Filtering using image spectra, containing all wavelength regions, from known samphire patches produced the most satisfactory mapping. Output salinity maps were validated at over 100 random sites. The HyMap salinity maps produced the most accurate results compared to CASI and Hyperion. HyMap successfully mapped highly saline areas with a good cover of samphire vegetation at Point Sturt without the use of multitemporal imagery or ancillary data such as topography or PIRSA soil attribute maps. CASI and Hyperion successfully mapped saltpan, however, their samphire maps showed a poor agreement with field data. These results suggest that perennial vegetation mapping requires all three visible, NIR and SWIR wavelength regions because the SWIR region contains important spectral properties related to halophytic adaptations. Furthermore, the unconvincing results of the CASI sea barley grass maps suggests that the optimal sensor for mapping both soil and vegetation salinity symptoms are airborne sensors with high spatial and spectral resolution, that incorporate the 450 to 1450 nm wavelength range, such as HyMap. This study has demonstrated that readily available software and image analysis techniques are capable of mapping indicators of varying levels of salinity. With the ability to map symptoms across multiple image strips, airborne hyperspectral imagery has the potential for mapping larger areas covering sizeable dryland agriculture catchments, closer in extent to single satellite images. This study has illustrated the advantage of the hyperspectral imagery over traditional soil mapping based on aerial photography interpretation such as the NLWRA Salinity 2000 and the PIRSA soil landscape unit maps. The HyMap salinity maps not only improved mapping of saline areas covered with samphire but also provided salinity maps that varied spatially within saline polygons.
Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2006.

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38

Al-Taher, Mohamad A. "Geostatistical applications to salinity mapping and simulated reclamation." Thesis, 1991. http://hdl.handle.net/1957/36881.

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Abstract:

Geostatistical methods were used to find efficient and accurate means for salinity assessment using regionalized random variables and limited sampling. The random variables selected, sodium absorption ratio (SAR), electrical conductivity (EC), and clay content were measured on samples taken over an area of fifteen square miles. Ordinary kriging and co-kriging were used as linear estimators. They were compared on the basis of average kriging variance and sum of squares for error between observed and estimated values. The results indicate a significant improvement in the average kriging variance and sum of squares by using co-kriging estimators. EC was used to estimate SAR because of the high correlation between them. This was not true for clay content. A saving of two-thirds of the cost and time was achieved by using electrical conductivity as an auxiliary variable to estimate sodium absorption ratio. The nonlinear estimator, disjunctive kriging, was an improvement over co-kriging in terms of the variances. More information at the estimation site is a more important consideration than when the estimator is linear. Disjunctive kriging was used to produce an estimate of the conditional probability that the value at an unsampled location is greater than an arbitrary cutoff level. This feature of disjunctive kriging aids salinity assessment and reclamation management. A solute transport model was used to show how saptially variable initial conditions influenced the amount of water required to reclaim a saline soil at each sampling point in a simulated leaching of the area.
Graduation date: 1992

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39

Kirkby, S. D. (Stephen Denis). "Managing dryland salinisation with an integrated expert system/geographic information system / S.D. Kirkby." Thesis, 1994. http://hdl.handle.net/2440/21517.

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Abstract:

Bibliography: leaves 119-218.
xiv, 218 leaves : ill. (some col.), maps (some col.) ; 30 cm.
Salt Manager represents the software system developed by this thesis to implement an interactive land classification methodology. An Expert System (ES), a Geographic Information System (GIS), remotely sensed information and a relational database management system (RDBMS) have been utilised to construct the methodology.
Thesis (Ph.D.)--University of Adelaide, Dept. of Geography, 1995

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40

Kirkby, S. D. (Stephen Denis). "Managing dryland salinisation with an integrated expert system/geographic information system / S.D. Kirkby." 1994. http://hdl.handle.net/2440/21517.

Full text

Abstract:

Bibliography: leaves 119-218.
xiv, 218 leaves : ill. (some col.), maps (some col.) ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Salt Manager represents the software system developed by this thesis to implement an interactive land classification methodology. An Expert System (ES), a Geographic Information System (GIS), remotely sensed information and a relational database management system (RDBMS) have been utilised to construct the methodology.
Thesis (Ph.D.)--University of Adelaide, Dept. of Geography, 1995

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41

Rahman, Muhammad M. "Risk based approach for managing salt accumulation in soil irrigated with recycled water." Thesis, 2015. http://hdl.handle.net/1959.7/uws:34195.

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Abstract:

Recycling is one of the viable options to attain sustainable management of wastewater. The supply and reuse of recycled water may play an important role in enhancing urban water supplies in many water-scarce parts of industrialised countries because of its reduced treatment cost relative to seawater desalination and imported surface water. One such reuse option includes application of recycled water for irrigating urban open fields. Past literature suggests that the continuous use of recycled water over a long period of time may lead to the accumulation of salt in the root zone. Salt transport models to quantify salt accumulation in soil exist, but these do not consider the stochastic nature of the elements of salt accumulation process. Moreover, none of the past studies propose a framework to manage and control the salt accumulation process due to recycled water irrigation by considering stochastic nature of different components. The study described in the thesis details a novel methodology adopted for the development and implementation of an integrated risk based approach to control sources of salinity and the level of treatment required to use recycled water in irrigation in a sustainable manner. The study included laboratory and field work and involved thorough investigation of site specific soil, data analysis, development of relationships among elements of salt accumulation process, and incorporated long-term prediction modelling result and scientific knowledge into a framework. One of the key investigations conducted was to understand and monitor salt accumulation process in columns using sensors in terms of depth of soil, type of soil and type of irrigation water. Data generated from these experiments and output from simulation were used to develop the framework. Therefore, the overall aim of this study was to develop a framework with the help of a probabilistic method, namely, Bayesian belief network (BBN) to manage the salinity in the root zone due to recycled water irrigation. Results from the column study show that due to recycled water irrigation, soil water electrical conductivity (ECSW) was higher in the upper part of the column (0-0.2 m) than the lower part. This is because only applied irrigation water could not leach the salt from upper part to downward. When simulated rainfall was applied (once in a week) in a loamy sand column along with recycled water (twice in a week), the average ECSW showed a decreasing pattern with time. In another column study with silty loam soil, average sodium adsorption ratio due to recycled water (EC = 0.8 dS/m) irrigation was 3.6 times more than the tap water (EC = 0.2 dS/m) irrigation and 1.4 times less than the synthetic saline water (EC = 2.0 dS/m) irrigation. In the same column study, it was observed that the ratio of soluble cations (Na+: Mg2+: Ca2+: K+) in the soil sample changed than its initial ratio at the beginning of the study. The change in the ration occurred because of exchanging cations between soil and the water added for irrigation. A salt transport model HYDRUS 1D was validated with experimental results and used to predict risk of salt accumulation in field condition. The salt transport modelling carried out in this study shows that in drought condition, yearly averages ECSW exceeded the maximum salinity tolerance threshold of 5.0 dS/m for rye pasture due to recycled water irrigation in a loamy sand paddock. The ECSW exceeded 1, 59, 79, 87 and 90% for the years from 1 to 5, respectively. In another modelling with future climate condition between years 2021 and 2040 shows that ECSW was 24% higher in loamy soil paddock compared to loamy sand paddock. Amount of leachate in the loamy sand paddock was 27% more than the amount leached from loamy paddock, which may pose a salinity risk to the ground water if there is a perched aquifer in the field at a depth < 1 m. BBN framework analyses identified that for root zone ECSW of 2.25 dS/m, it is 92% probable that the Na+ concentration of the root zone soil water would be in the range of 5 – 15 mmol(c)/L; for ECSW of 16.5 dS/m, there is 86% probability that the Na+ concentration of root zone soil water would be in the range of 30 – 35 mmol(c)/L. Furthermore, over the study period of 2021 to 2040, it was found that the reduction of the posterior mean of recycled water EC by 13% (from μ=0.92 to μ=0.8 dS/m), brings the average root zone ECSW down from 6.5 dS/m to 4 dS/m, which is within the salinity threshold limit for rye pasture. The BBN framework also identified the most significant sources of salinity contributing to wastewater and proposed control strategy of those sources to minimise the salt accumulation in the soil for a sandy loam oval irrigated with recycled water. Results show that accumulation of salt in the root zone was largely due to the salt load in the wastewater stream from washing machines and the salt load in the wastewater from toilets was the second most influential source. It was found that by controlling multiple sources at the same time significantly reduces salt accumulation in the soil. It was observed that by using environmental friendly detergents reduce the TDS load in the laundry stream by 4 to 7 times and Na+ load by 2 times than popular brand detergents. Irrigation scheduling with recycled water is typically done while considering only the soil moisture levels. The study reported in this thesis proposes that besides considering the soil moisture levels, salt accumulation within the soil must be considered while irrigating open fields using recycled water. Proposed methods and outcome of this research would provide vital knowledge about the uncertainty associated with root zone salinisation of urban open fields, and better management and control of root zone salinity due to irrigation with recycled water. The study highlighted that any strategies that help in the reduction of salt in the recycled water will be beneficial in managing the soil salinity as a result of recycled water use for irrigating open fields. Hence, the proposed decision making tool for controlling the risk of soil salinisation can assist in developing recycled water irrigation schemes which are sustainable over the long-run.

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Guerrero-Rodriguez, Juan de Dios. "Growth and nutritive value of lucerne ( Medicago sativa L. ) and Melilotus ( Melilotus albus Medik. ) under saline conditions." 2006. http://hdl.handle.net/2440/37866.

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Dryland salinity is a major and expanding threat to agricultural land in Australia. Animal production from forages grown on saline land is perhaps its most promising economic use. Glycophytic forage legumes have been evaluated under saline conditions mainly for agronomic characteristics and, to a lesser extent, for nutritive quality to animals. Plant growth and its nutritive quality are interrelated, but a decline in yield in response to salinity may be associated with effects on the chemical constituents of the plant since soil salinity affects plant metabolism. This research aimed to investigate changes in the components of yield and nutritive value of two legumes species. Lucerne ( Medicago sativa ) and Melilotus ( Melilotus albus ) were exposed to different levels of NaCl in the range of 0 to 110 mM NaCl. The research tested the hypothesis that the components of plant nutritive value are not as sensitive to salinity as shoot biomass production since the adaptive mechanisms of the plant lessen harmful effects of the salts. For both plant species, salinity decreased leaf and stem dry matter production, but increased leaf - to - stem ratio. In addition, salinity resulted in earlier flowering in Melilotus. Mineral composition was the most sensitive component of forage quality. Calculated sodium chloride concentrations were up to 125 g / kg DM in lucerne and 39 g / kg DM in Melilotus when irrigated with 110 mM NaCl. The concentrations of calcium and magnesium decreased in both species and approached the marginal range for animal production. Zinc concentration also decreased while potassium decreased in stems of lucerne only. The digestible organic matter ( DOMD ) in response to salinity varied between species. At the highest salt concentration, the whole shoot ( i.e., leaf and stem ) of lucerne decreased up to 4 percentage units while Melilotus increased by 6 percentage units. In lucerne, DOMD was influenced by a high concentration of soluble ash in leaf and stem and, in Melilotus, by an increase in the organic matter content of leaf and a reduction in lignin concentration in stem, which favoured higher digestibility. These results were supported by a histological study in which an increase in starch in Melilotus leaf, and a lower proportion of xylem in relation to parenchyma in stems, was measured. Crude protein concentration was not compromised and, in relation to Melilotus, coumarin concentration did not increase with salinity. In conclusion, the reduction in DM production of species with similar salt tolerance does not necessarily correspond to an equivalent reduction in nutritive value. This research represents the most detailed study into effects of salinity on glycophytic forage legumes. Results show that while some aspects of forage quality ( e.g., minerals composition and energy ) are strongly influenced by salinity, other aspects ( e.g., protein ) remain relatively unaffected. These findings have implications for development of productive grazing systems on saline agricultural land.
Thesis (Ph.D.)--School of Agriculture, Food and Wine, 2006.

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Soares, Bruno Miguel Ribeiro. "Effect of halophilic bacteria from Aveiro salt pans in the attenuation of saline stress in plants." Master's thesis, 2018. http://hdl.handle.net/10773/25368.

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Soil salinization is a globally growing problem, and several approaches have been proposed to mitigate its effects on the productivity of plants of economic interest. The use of halophilic or halotolerant bacteria as plant growth promoters is one of the strategies recommended for the mitigation of salt stress. However, halotolerant bacteria isolated from the rhizosphere of halophyte plants are the most commonly used inoculum. The objective of this work was to evaluate the potential of halophilic bacteria, isolated from a salt pan, in the attenuation of saline stress Lactuca sativa, used as a model crop glycophyte. A collection of strains isolated from Santiago da Fonte saltpans (Aveiro) representing the genera Bacillus, Halobacillus, Idiomarina and Marinobacter, was analyzed for some characteristics considered as advantageous in the colonization and promotion of growth of host plants. The production of extracellular enzymes in presence of 0, 20 and 100 NaCl, as well as the ability to solubilize phosphate and produce 1-aminocyclopropane-1-carboxylate deaminase were tested. H. locisalis and I. seosinesis, considered as more interesting in terms of plant growth promoting traits, were tested separately and together as inoculum in lettuce seeds. A factorial experimental design was applied to test the effect of inoculation and salinity of the irrigation water on the efficiency of seed germination and plant growth. Germination efficiency was strongly affected by salinity and no significant effects of inoculation were observed. The germination efficiency was lower at 10 NaCl than at salinity 0 and the weight of the plants was significantly lower in the plants inoculated with the consortium of isolates than in the uninoculated plants. Plants inoculated with the consortium and grown at salinity 10 had lower water content. When used separately, H. locisalis or I. seosinesis caused an increase in leaf size in plants cultivated in salinity, in relation to the inoculated control. Inoculation did not cause a significant effect on chlorophyll fluorescence. Although no evidence of attenuation of saline stress by inoculation was detected, H. locisalis inoculum showed a positive effect on the growth of plants in non-saline conditions, indicating a potential as a growth promoting bacterium of plants of agricultural interest.
A salinização dos solos é um problema crescente a nível global e têm sido várias as abordagens propostas para atenuar os seus efeitos na produtividade de plantas de interesse económico. O uso de bactérias halófilas ou halotolerantes como promotoras do crescimento de plantas, é uma das estratégias preconizadas para a mitigação do stresse salino. No entanto, são normalmente usadas como inóculo bactérias halotolerantes isoladas da rizosfera de plantas halófitas. O objetivo deste trabalho foi avaliar o potencial de bactérias halófilas, isoladas de uma marinha de sal, na atenuação do stresse salino em Lactuca sativa, usada como modelo de glicófita de interesse agrícola. Uma coleção de estirpes isoladas da marinha de Santiago da Fonte (Aveiro) representando os géneros Bacillus, Halobacillus, Idiomarina e Marinobacter, foi analisada quanto a algumas caraterísticas consideradas como vantajosas na colonização e promoção do crescimento de plantas. Testou-se a produção de enzimas extracelulares em salinidades 0, 20 e 100 de NaCl bem como a capacidade para solubilizar fosfato e produzir ácido 1-aminociclopropano-1-carboxilato desaminase. H. locisalis e I. seosinesis, considerados como mais interessantes face às características promotoras do crescimento, foram testados separadamente e em conjunto, como inóculo em sementes de alface. Foi aplicado um desenho experimental fatorial para testar o efeito da inoculação e da salinidade da água de irrigação sobre a eficiência de germinação das sementes e crescimento das plantas. A eficiência de germinação foi fortemente afetada pela salinidade não tendo sido observados efeitos significativos de nenhum dos inóculos testados. Na condição de salinidade 10, a eficiência de germinação foi mais baixa do que com salinidade 0 e o peso das plantas foi significativamente menor nas plantas inoculadas com o consórcio de isolados do que nas plantas não inoculadas. As plantas inoculadas com o consórcio e cultivadas na salinidade 10 apresentaram menor teor de água. As plantas inoculadas separadamente com H. locisalis ou com I. seosinesis cultivadas em salinidade 0, revelaram um aumento do tamanho das folhas relativamente ao controle não inoculado. Embora não tenham sido encontradas evidências de atenuação do stresse salino, o inóculo H. locisalis apresentou um efeito positivo no crescimento das plantas em condições não-salinas, o que demonstra um potencial como bactéria promotora do crescimento de plantas de interesse agrícola.
Projeto nº 029736 - Programa Operacional Regional do Centro (02/SAICT/2017).
Mestrado em Ecologia Aplicada

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Leske, Anthony. "The development of a method for the inclusion of salinity effects into environmental life cycle assessments." Thesis, 2003. http://hdl.handle.net/10413/4339.

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The work presented in this thesis stemmed out of the apparent lack of a method for incorporating salinity effects into environmental life cycle assessments. Salination of the water resources is a well-known problem in South Africa, and is of strategic concern. Any environmental decision support. tool that does not allow the evaluation of salinity effects therefore has limited applicability in the South African context. The starting-point for the work presented in this thesis was to evaluate existing impact categories, and the characterisation models used to calculate equivalency factors for these impact categories, in an attempt to incorporate salinity effects into existing categories and/or characterisation models. The types of effects that elevated (above normal background levels) dissolved salt concentrations have on the natural and man-made environment were evaluated, and it was concluded that, although there was some overlap with existing impact categories, some of the salinity effects could not be described by existing impact categories. It was also concluded that there are clear and quantifiable causal relationships between releases to the environment and salinity effects. A separate salinity impact category was therefore recommended that includes all salinity effects, including; aquatic ecotoxicity effects, damage to man-made environment, loss of agricultural production (livestock and crops), aesthetic effects and effects to terrestrial fauna and flora. Damage to the man-made environment is evaluated in terms of effects on equipment and structures, interference with processes, product quality and complexity of waste treatment, and is used as an indicator for the environmental consequences derived from the caused additional activity in the man-made environment. Once a conceptual model for a separate salinity impact category had been formulated, existing characterisation models were evaluated to determine their applicability for modelling salinity effects. Salination is a global problem, but generally restricted to local or regional areas, and in order to characterise salinity effects, an environmental fate model would be required in order to estimate salt concentrations in the various compartments, particularly surface and subsurface water. A well-known environmental fate and effect model was evaluated to determine if it could be used either as is, or in modified form to calculate salinity potentiaIs for LCA. It was however concluded that the model is not suitable for the calculation of salinity potentials, and it was therefore decided to develop an environmental fate model that would overcome the limitations of existing model, in terms of modelling the movement of salts in the environment. In terms of spatial differentiation, the same approach that was adopted in the existing model was adopted in developing an environmental fate model for South African conditions. This was done by defining a aunit South African catchmenta (including the air volume above the catchment), which consists of an urban surface; rural agricultural soil (and associated soil moisture); rural natural soil (and associated moisture), groundwater (natural and agricultural) and one river with a flow equal to the sum of the flows of all rivers in South Africa, and a concentration equal to the average concentration of each river in the country. A non steady-state environmental fate model (or, hydrosalinity model) was developed that can predict environmental concentrations at a daily time-step in all the compartments relevant to the calculation of salinity potentials. The environmental fate model includes all the major processes governing the distribution of common ions (sodium, calcium, magnesium, sulphate, chloride and bicarbonate) in the various compartments, and described as total dissolved salts. The effect factors used in the characterisation model were based on the target water quality ranges given by the South African Water Quality Guidelines in order to calculate salinity potentials. The total salinity potential is made up of a number of salinity effects potentials, including; damage to man-made environment, aquatic ecotoxicity effects, damage to man-made environment, loss of agricultural production (livestock and crops), aesthetic effects and effects to terrestrial fauna and flora. The total salinity potentials for emissions into the various initial release compartments are shown in the table below. Initial release compartment Atmosphere River Rural natural surface Rural agricultural surface Total salinity potential (kg TDS equJkg) 0.013 0.16 0.03 1.00 The salinity potentiaIs are only relevant to South African conditions, and their use in LeA in other countries may not be applicable. This, in effect, means that the life cycle activities that generate salts should be within the borders of South Africa. It has been recognised that the LCA methodology requires greater spatial differentiation. Salination is a global problem, but generally restricted to local or regional areas on the globe, and it is foreseen that local or regional salinity potentials would need to be calculated for different areas of the earth where salinity is a problem. The LCA practitioner would then need to know something about the spatial distribution of LCA activities in order to apply the relevant salinity potentials. The LCA practitioner should also take care when applying the salinity potentials to prevent double accounting for certain impacts. Currently, this is simple because no equivalency factors exist for common ions, or for total dissolved salts as a lumped parameter. The distribution of salinity potentials, which make up the total salinity potential, appears to be supported by the environmental policies and legislation of South Africa, in which irrigation using saline water is listed as a controlled activity, and subject to certain conditions. The major recommendations regarding further work are focussed on the collection of data that will allow further refinement of the model, and to decrease the uncertainty and variability associated with the results. The values of the published equivalency factors are dependent on the mathematical definition of the local or regional environment, and these values have been calculated for Westem European conditions. Equivalency factors may vary by several orders of magnitude, depending on how the local or regional conditions have been defined. It is therefore recommended that the model developed in this work ultimately be included into a global nested model that can be used to calculate equivalency factors for other compounds, including heavy metals and organic compounds. This would result in equivalency factors for all compounds that are relevant to South Africa.
Thesis (Ph.D.)-University of Natal, Durban, 2003.

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Humphries, Alan Wayne. "New challenges for lucerne in southern Australian farming systems : identifying and breeding diverse lucerne germplasm to match these requirements." Thesis, 2008. http://hdl.handle.net/2440/50451.

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Lucerne is a deep-rooted perennial pasture that is promoted to land managers in southern Australia to mitigate the effects of dryland salinity, a problem of national significance caused by the replacement of native trees and shrubs with annual crops and pastures. In recent years, the acceptance of climate change has provided further rationale for increasing the use of perennial legumes in our farming systems. Perennial legumes have a role in offsetting C02 emissions by sequestering C and N in soil, and provide new, resilient options for future farming in a warmer and more variable climate. This research has focused on evaluating the diverse range of germplasm found in lucerne (Medicago sativa spp.) for a range of attributes in order to determine its compatibility with existing and future farming systems in southern Australia. Regional field evaluation at 8 sites in southern Australia showed that lucerne is a broadly adapted and robust plant. After 3 years, plant density ranged from 2-55 plants / m2 with differences in persistence attributed to tolerance to a combination of stresses including soil acidity, saline and sodic subsoils, drought conditions and persistent heavy grazing. Highly winter-active lucerne (class 9-10) was confirmed to be the most suitable group for short phase rotations in southern Australia, providing grazing is well managed. This germplasm was less persistent than other winter activity groups, but produces more total herbage yield in environments with winter dominant rainfall patterns. Highly winter-active lucerne has poor persistence under continuous grazing, but this may aid in its removal when used in rotation with crops. Winteractive germplasm (class 6-8) was more grazing tolerant and persistent, making it the most suitable group for longer phase rotations (>4 years), or where more flexible grazing management practices are required (i.e. 35 days grazing followed by 35 days recovery). Individual grazing tolerant plants from this group were selected and randomly inter-mated to form new breeder’s lines in the development of a grazing tolerant cultivar. For the first time, the high water-use of a farming system involving wheat overcropped into lucerne is presented. Lucerne over-cropped with wheat used an additional 43-88 mm of water in comparison to continuous wheat at Roseworthy and Katanning respectively. Over-cropping reduced wheat yield by 13-63%, but it can be more efficient in terms of land area to grow lucerne and wheat as a mixture than on separate parcels of land. Very winter-dormant lucerne (class 1-2) appears to be less competitive with winter cereal crops during wheat establishment. It may also be possible to reduce lucerne’s competition with wheat at the critical stage of anthesis, with low spring yielding lucerne varieties identified in this research (SA37908). This group of plants provides excellent potential for the development of high water-use farming systems because they are grazing tolerant and persistent, and have summer forage production and sub-soil water extraction rates that are equivalent to winter active lucerne. The research has been used to identify the perfect ideotype for lucerne in phase farming and over-cropping systems, which can be used to set targets in future breeding programs. The research also highlights current opportunities for the integration of lucerne into southern Australian farming systems to help curb the spread of dryland salinity and reduce the impact of climate change.
Thesis (Ph.D.) - University of Adelaide, School of Agriculture, Food and Wine, 2008

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46

Humphries, Alan Wayne. "New challenges for lucerne in southern Australian farming systems : identifying and breeding diverse lucerne germplasm to match these requirements." 2008. http://hdl.handle.net/2440/50451.

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Abstract:

Lucerne is a deep-rooted perennial pasture that is promoted to land managers in southern Australia to mitigate the effects of dryland salinity, a problem of national significance caused by the replacement of native trees and shrubs with annual crops and pastures. In recent years, the acceptance of climate change has provided further rationale for increasing the use of perennial legumes in our farming systems. Perennial legumes have a role in offsetting C02 emissions by sequestering C and N in soil, and provide new, resilient options for future farming in a warmer and more variable climate. This research has focused on evaluating the diverse range of germplasm found in lucerne (Medicago sativa spp.) for a range of attributes in order to determine its compatibility with existing and future farming systems in southern Australia. Regional field evaluation at 8 sites in southern Australia showed that lucerne is a broadly adapted and robust plant. After 3 years, plant density ranged from 2-55 plants / m2 with differences in persistence attributed to tolerance to a combination of stresses including soil acidity, saline and sodic subsoils, drought conditions and persistent heavy grazing. Highly winter-active lucerne (class 9-10) was confirmed to be the most suitable group for short phase rotations in southern Australia, providing grazing is well managed. This germplasm was less persistent than other winter activity groups, but produces more total herbage yield in environments with winter dominant rainfall patterns. Highly winter-active lucerne has poor persistence under continuous grazing, but this may aid in its removal when used in rotation with crops. Winteractive germplasm (class 6-8) was more grazing tolerant and persistent, making it the most suitable group for longer phase rotations (>4 years), or where more flexible grazing management practices are required (i.e. 35 days grazing followed by 35 days recovery). Individual grazing tolerant plants from this group were selected and randomly inter-mated to form new breeder’s lines in the development of a grazing tolerant cultivar. For the first time, the high water-use of a farming system involving wheat overcropped into lucerne is presented. Lucerne over-cropped with wheat used an additional 43-88 mm of water in comparison to continuous wheat at Roseworthy and Katanning respectively. Over-cropping reduced wheat yield by 13-63%, but it can be more efficient in terms of land area to grow lucerne and wheat as a mixture than on separate parcels of land. Very winter-dormant lucerne (class 1-2) appears to be less competitive with winter cereal crops during wheat establishment. It may also be possible to reduce lucerne’s competition with wheat at the critical stage of anthesis, with low spring yielding lucerne varieties identified in this research (SA37908). This group of plants provides excellent potential for the development of high water-use farming systems because they are grazing tolerant and persistent, and have summer forage production and sub-soil water extraction rates that are equivalent to winter active lucerne. The research has been used to identify the perfect ideotype for lucerne in phase farming and over-cropping systems, which can be used to set targets in future breeding programs. The research also highlights current opportunities for the integration of lucerne into southern Australian farming systems to help curb the spread of dryland salinity and reduce the impact of climate change.
http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1344608
Thesis (Ph.D.) - University of Adelaide, School of Agriculture, Food and Wine, 2008

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Gomboso, Jeanette. "A hydrogeological-economic modelling approach to dryland salinity in the North Stirling Land Conservation District, Western Australia." Phd thesis, 1995. http://hdl.handle.net/1885/115204.

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Associated with the problems of rising groundwater levels and dryland salinity are the conflicting economic and environmental objectives which aim to maximise net revenue from agriculture whilst still conserving the ecological standards of the natural environment. From an economic perspective, the central objective of salinity management should be to obtain the socially optimum value of resource use (including conservation) over time. Economics can contribute to the resolution of natural resource conflicts, by concentrating specifically on the allocation of scarce resources among competing demands, and determining which actions are economic from a catchment perspective. From an environmental standpoint, it is important to ensure that the natural environment is conserved not only today, but also for future generations. Despite the importance of managing the natural resource base from both an environmental and economic perspective, numerical models, which simulate the spatial and temporal movement of saline groundwater, have not been used extensively in economic analyses. Consequently, the focus in this thesis, is on the economic-physical system modelling of dryland salinity, in Western Australia. A transient hydrogeological-economic model has been developed and applied to the North Stirling Land Conservation District, a severely salt-affected area located in south-west Western Australia, to assess the current and future impacts of varying a catchment's land use pattern on groundwater levels and agricultural production. Several alternative salinity management options which may be applied to the District have been simulated, including an agronomic practice and an agroforestry strategy. Results of the simulations show that the choice of alternative land uses that should be adopted in order to reduced losses in gross margins in an area affected by dryland salinity, will depend primarily upon the effects of the various crop, pasture and tree species planted on the dynamic and spatial variations in groundwater levels, and the relative economic returns of those species. The 1995 value of potential gross margin receipts over the nine-year period (1992 to 2000, inclusive) is expected to be $10 million. By maintaining current land use practices across the study area, groundwater levels are estimated to rise by 1 m and the opportunity cost of salinity, in terms of foregone agricultural production, is estimated to be almost $6.7 million over this period. By adopting a discharge zone planting (or agronomic) strategy, whereby salt-tolerant shrubs are established on saline areas th a t can no longer su s ta in traditional agricultural production, piezometric heads are estimated to decrease by 0.3 m over the same nine-year period and the opportunity cost of salinity is estimated to decline by $720,000 compared to the 'do-nothing' approach. Alternatively, if agroforestry techniques (in this case alley farming) are introduced to those areas within the NSLCD study area that currently support traditional crops and pastures, average piezometric heads at the end of the forecasting period (year 2000) are estimated to be 0.4 m lower than average heads predicted under the agronomic option (or 0 .7 m com pared to the do-nothing' approach). Gross margins are expected to be $790,000 higher under the agroforestry approach than if existing farming practices are maintained. However, unlike the alternative scenarios modelled in this study, the estimated gross margins are expected to increase over the forecasting period as the higher water-using trees planted throughout the study area cause groundwater levels to decline further. On a more general note, the modelling approach developed here is a generic one that can be successfully applied to many areas affected by salinity. Such models are beneficial as they provide additional information which helps the community, farmers, Landcare groups and the government make important decisions on how best to manage the agricultural and natural resources upon which we rely for productivity and environmental amenity.

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Burns, Erick R. "Thermodynamics of non-dilute saline solutions in variably saturated porous media." Thesis, 2004. http://hdl.handle.net/1957/29363.

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Non-dilute salt strength solutions occur in many near surface geologic environments. In order to better understand the occurrence and movement of the water and salt, mathematical models for this non-ideal fluid need to be developed. Initial boundary value problems may then be solved to predict behavior for comparison with observations. Using the principles of equilibrium reversible and irreversible thermodynamics, relationships describing the thermo-physics of non-dilute saline solutions in variably saturated porous media are investigated. Each of four central chapters investigates a particular aspect of the flow of saline solutions through porous media. The first chapter derives the general relationships describing the effects of salt on the vapor content in the gas phase and also on the liquid pressure. The second chapter summarizes an example using the new theory for sodium chloride (NaCl) from zero to saturated strength. Additional terms beyond the dilute approximation are shown to be more important in very dry, fine textured soils with significant salt content. The third chapter derives the salt corrections for Darcy-type flow laws for variably saturated porous media, and an example for NaCl is given. Agreement between theory and experimental data is good, though there appear to be some unaccounted for effects. These effects may be the result of ionic interaction of the salt with the loamy sand used, and/or the effect of hysteresis of the water content-pressure relationship. The final chapter investigates two fundamental assumptions commonly used in process thermodynamics when considering mixtures described by porous media, saline water, and moist air. The first assumption is that temperature is the generalized intensive variable associated with entropy. The second assumption is that the form of the differential of total energy is known a-priori. It is shown that the first assumption is suspect under some circumstances, and a generalized notion of how to select extensive variables for a given system is introduced for comparison with the second assumption. Examples comparing the "usual" and new theories are accomplished for ideal gases and for isotropic Newtonian liquids, with results being favorable except possibly for the Gibbs-Duhem Relation of the Newtonian liquid for the "usual" theory.
Graduation date: 2005

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Ojo, Olumuyiwa Idowu. "Mapping and modeling of irrigation induced salinity of Vaal-Harts irrigation scheme in South Africa." Thesis, 2013. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000478.

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D. Tech. Engineering: Civil.
Aims to map and model the salinity trends in Vaal Harts irrigation schemes in Jan Kempdorp, Northern Cape Province of South Africa using Landsat SRS, GIS computational tools (IDRIS and ERDAS). The resulted maps and models will aid the effective management of salinity problem and thereby minimizing its occurrence in the future through planning and policy formulation, on the irrigation scheme within the context of environmental sustainability.

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Wannakomol, Akkhapun [Verfasser]. "Soil and groundwater salinization problems in the Khorat Plateau, NE Thailand : integrated study of remote sensing, geophysical and field data = Probleme der Boden- und Grundwasserversalzung in der Khorat Hochebene, NE Thailand / vorgelegt von Akkhapun Wannakomol." 2005. http://d-nb.info/975936085/34.

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Dissertations / Theses on the topic 'Soil salinization'

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