Дисертації з теми "Soils, Salts in Victoria"
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1
Nathan, Muhammad. "Clay movement in a saline-sodic soil toposequence." Title page, contents and summary only, 2001. http://web4.library.adelaide.edu.au/theses/09A/09an274.pdf.
Повний текст джерелаАнотація:
Includes bibliographical references (leaves 78-86) In the Herrmanns sub-catchment in the Mt. Lofty Ranges (near Mt. Torrens) soil sodicity was the dominant factor in causing clay to disperse in the eroded area along the foot slopes, wheras in non-eroded areas of the mid-slopes and on the stream banks, the dispersive power of sodicity was attenuated by the flocculative power of other soil properties.
2
Barzegar, Abdolrahman. "Structural stability and mechanical strength of salt-affected soils." Title page, contents and abstract only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phb296.pdf.
Повний текст джерелаАнотація:
Copies of author's previously published articles in pocket inside back cover. Bibliography: leaves 147-160. This thesis outlines the factors affecting soil strength and structural stability and their interrelationship in salt-affected soils. The objectives of this study are to investigate the influence of clay particles on soil densification and mellowing, the mellowing of compacted soils and soil aggregates as influenced by solution composition, the disaggregation of soils subjected to different sodicities and salinities and its relationship to soil strength and dispersible clay and the effect of organic matter and clay type on aggregation of salt-affected soils.
3
Marwan, M. M. "Changes in physical and chemical properties of saline-sodic soils during removal of salts by leaching with water." Thesis, University of Reading, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234663.
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4
Vernon, Daniel Marc. "Molecular biology of salt tolerance in the facultative halophyte Mesembryanthemum crystallinum: Identification and regulation of stress-responsive mRNAs." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/185921.
Повний текст джерелаАнотація:
As sessile organisms, plants are subject to numerous environmental insults. Of these, salinity is one of the most widespread and important in terms of limiting plant distribution and productivity. Molecular studies have established that plants challenged by high salinity respond by increasing expression of specific genes. A functional role for the products of such genes in stress tolerance has not been established, however, and little is known about the biochemical mechanisms that allow plants to tolerate osmotic stress. Mesembryanthemum crystallinum is a facultative halophyte capable of adjusting to and surviving in highly saline conditions. I have generated and screened a subtracted cDNA library to identify mRNAs that accumulate during this plant's adaptation to salt stress. Three mRNAs were identified that increased in abundance in leaf tissue of salt stressed plants. Patterns of induction for these mRNAs differed. The most dramatically-induced mRNA, Imt1, was characterized in depth. Imt1 expression was induced in leaves and, transiently, in roots. Nuclear run-on assays indicated that the gene is transcriptionally regulated. In several respects, the expression of Imt1 differed from that of other salinity-responsive genes involved in photosynthetic metabolism in M. crystallinum: The mRNA was induced by salinity and low temperature, but not by drought, and its induction by stress was not influenced by plant age. Imt1 encoded a predicted polypeptide of Mr 40,250 which exhibited sequence similarity to several hydroxymethyl transferases. The IMT1 protein was expressed in E. coli and identified by functional assay as a myo-inositol methyl transferase that catalyzes the first step in the biosynthesis of the cyclic sugar alcohol pinitol. The presence of high levels of sugar alcohols has been correlated with osmotolerance in a wide range of organisms, and the stress-initiated transcriptional induction of IMT1 expression in a facultative halophyte provides the strongest support to date for the importance of sugar alcohols in establishing tolerance to osmotic stress in higher plants. The ability of this methyl transferase to generate a putative osmoprotectant from a ubiquitous plant substrate makes it an attractive candidate enzyme for the creation of stress-resistant transgenic plants.
5
Gao, Yuan. "Changes of tomato fruit composition in response to salinity /." Title page, contents and summary only, 1991. http://web4.library.adelaide.edu.au/theses/09A/09ag211.pdf.
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6
Mulumba, Lukman Nagaya. "Land use effects on soil quality and productivity in the Lake Victoria Basin of Uganda." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1095711869.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Ohio State University, 2004.Title from first page of PDF file. Document formatted into pages; contains xv, 166 p.; also includes graphics (some col.). Includes bibliographical references (p. 134-153).
7
Hagi-Bishow, Mohamed. "Assessment of LEACHM-C model for semi-arid saline irrigation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0007/MQ44178.pdf.
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8
Wong, Vanessa Ngar Lai. "The effects of salinity and sodicity on soil organic carbon stocks and fluxes /." View thesis entry in Australian Digital Theses Program, 2007. http://thesis.anu.edu.au/public/adt-ANU20080428.223144/index.html.
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9
PFEIFFER, CHARLES MICHAEL. "GROWTH AND NUTRITION OF MYCORRHIZAL GUAYULE IN SALINE SOILS (ENDOMYCORRHIZAE, GLOMUS INTRARADICES, SALINITY)." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183780.
Повний текст джерелаАнотація:
Inoculation of Parthenium argentatum (guayule) with an endomycorrhizal fungus (Glomus intraradices) increased the growth of guayule in saline and non-saline soils low in available phosphorus. Addition of 100 ug/g of P as Ca(H2PO4)2 to soils low in available phosphorus was as efficient as G. intraradices in stimulating the growth of guayule. The concentrations and total plant accumulations of minerals within guayule shoots varied depending on growth of the plants and the minerals assayed. In most cases, the concentrations of Cu, Zn, Mn, Na and Cl increased in the shoot tissues of guayule grown in soils which contained added NaCl. Generally, addition of phosphorus to the soil resulted in decreased concentrations of Cu and Zn and increased concentrations of PO4 in guayule shoots. The total accumulations of minerals by guayule was directly influenced by the biomass of plants. Increased biomass of plants generally resulted in increased total accumulations of the minerals assayed. The influence of mycorrhizae on the accumulations of minerals by guayule grown in a saline soil was evaluated by comparing nonmycorrhizal plants with the same biomass and phosphorus nutrition as mycorrhizal plants. Mycorrhizae increased the concentrations and total plant accumulations of Zn and decreased the content of Cl within guayule shoots. Colonization of guayule roots by G. intraradices was not affected by addition of P to the soil. Addition of NaCl to the soil decreased the formation of arbuscules and vesicles within roots and increased the incidence in which no fungal structures were seen. The combination of P and NaCl added to soil had a synergistic effect on the mycorrhizae of guayule. Addition of both P and NaCl to soil reduced the occurrence of hyphae, arbuscules and vesicles within roots and decreased the overall infection of guayule roots by G. intraradices.
10
Chang, Jingwei, and 常经纬. "Effect of pore water salt content on the coefficient of earth pressure at rest of fine-grained soils." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/202253.
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11
Amer, Saud Abdulaziz 1953. "SPECTRAL REFLECTANCE MEASUREMENTS OF SALT-AFFECTED SOIL." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276542.
Повний текст джерелаАнотація:
Salt-affected soils have undermined the effectiveness of agricultural development of considerable areas of the world, especially in the arid and semi-arid regions. This research is set out for the direct measurement of salt-affected soil. Two experiments were conducted to study the influence of different salt types and concentrations on spectral reflectance of soil. In the first experiment, five different salts (Na₂SO₄, NaHCO₃, CaCO₃, CaCl₂ and NaCl) were mixed individually with Gila soil at 0.51, 1.51 and 3.0% by weight. The second experiment was conducted to examine the spectral response of sodium sulfate and sodium bicarbonate (individually and in combination) in Gila soil at 3.0 and 6.0% by weight. Reflectance measurements were made over all soil treatments under different moisture conditions. Upon drying (24-hour after wetting), different salt types and concentrations showed different spectral response. The chemical analysis of soil samples have indicated some important relationships which influenced, directly and indirectly, the spectral reflectance of soil surfaces.
12
Nava, Leon Jose Angel 1956. "CHLORIDE AND NITRATE DISTRIBUTION IN THE SOIL WITH FURROW AND BURIED DRIP IRRIGATION (SALINITY, SANDY LOAM)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/276671.
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13
Black, Amanda. "Bioavailability of cadmium, copper, nickel and zinc in soils treated with biosolids and metal salts." Lincoln University, 2010. http://hdl.handle.net/10182/1561.
Повний текст джерелаАнотація:
It is widely accepted that bioavailability, rather than total soil concentration, is preferred when assessing the risk associated with metal contamination. Despite this, debate continues on what constitutes a bioavailable pool and how to best predict bioavailability, especially in relation to crop plants. The overall aim of this thesis was to assess and validate measures of cadmium (Cd), copper (Cu), nickel (Ni) and zinc (Zn) bioavailability in a range of soils amended with metal salts and biosolids. Six potential measures of bioavailability were investigated and compared: total metal; 0.04 M EDTA extraction; 0.05 M Ca(NO₃)₂ extraction; soil solution extracted using rhizon probes; effective solution concentration (CE) determined using diffusive gradients in thin films (DGT); and modelled free ion activities (WHAM 6.0). These were compared to shoot metal concentrations obtained from plants grown in three soils with contrasting properties treated with biosolids and metal salts. The first study involved a wheat seedling (Triticum aestivum) assay carried out under controlled environmental conditions on incubated soils treated with metal salts and biosolids. Results showed that the presence of biosolids resulted in increases of DOC, salinity, Ca and Mg in soil solution as well as total concentrations of Cu and Zn, dry matter was also adversely affected by increased levels of salinity. The addition of biosolids did not significantly alter the extractability or solubility of Cd, Cu, Ni and Zn although concentrations of Cd in shoots were significantly lower in plants grown in biosolids amended soils compared with unamended soils. The second study involved a field experiment that used 20 cm diameter by 30 cm deep soil monoliths of the same three soils treated with metals and biosolids, and perennial ryegrass (Lolium perenne) was grown for 24 months. Results revealed the addition of biosolids significantly increased the amount of DOC, salinity, Ca and Mg in solution. The presence of biosolids also significantly altered the bioavailability of Cd, Cu, Ni and Zn, as measured by soil solution, CE and free ion activity. However, this change had little effect on plant metal uptake. The length of time following treatment application had the greatest effect on soil chemistry and metal availability, resulting in pH decreases and increases in DOC, soil solution salinity, Ca and Mg. The free ion activities of each metal increased with time, as did soil solution Cd and Zn and CE-Cu, with results for Zn indicative of migration through the soil profile with time. Plant uptake of Ni and Zn also changed with time. Nickel concentrations in shoots decreased, while concentrations of Zn in shoots increased. The findings from the two studies demonstrated that biosolids increased the amount of DOC, salinity, Ca and Mg present in soil solution. In the lysimeter study measures of metal availability were affected in soils amended with biosolids, but this did not effect shoot concentrations. The overall predictive strengths of the six potential measures of bioavailability was investigated using results from the previously described experiments and related studies carried out by ESR and Lincoln University using nine different soils amended with combinations of biosolids and metal salts. Of the four metals Ni provided the strongest correlations between metal bioavailability and shoot concentrations, with 0.05 M Ca(NO₃)₂ extraction giving the strongest relationship for Ni concentrations in shoots (r² = 0.73). This suggests that the solubility of Ni is highly indicative of shoot concentrations and that Ca(NO₃)₂ is a robust measure of Ni bioavailability. In addition Ca(NO₃)₂ provided the best estimate of Zn bioavailability (r² = 0.65), and CE-Cd provided the best measure of Cd bioavailability, although it could only describe 47 % of shoot Cd concentration. Results for Cu were typical of previously described studies as assays of Cu availability are almost always poorly correlated with shoot concentrations, with total Cu having the strongest relationship (r² = 0.34). Methods based on the extractability and solubility of Cu in soils were poor indicators of Cu concentration in shoots. Overall, the addition of biosolids did not alter the outcome of these bioavailability assays, and results indicated that total metal concentrations present in the soils and biosolids matrix, plus length of time since soil treatment, had a greater affect on metal bioavailability.
14
Albuquerque, Josà Alfredo de. "Evaluation of environmental liabilities of degradeted soils by salts in Curu Pentecoste Perimeter irrigated, Ceara." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14817.
Повний текст джерелаАнотація:
nÃo hÃA pesquisa tem como base fÃsica o PerÃmetro Irrigado Curu Pentecoste, jurisdicionado ao Departamento Nacional de Obras Contra as Secas, e como objetivo geral quantificar a extensÃo, o custo da reversÃo e a responsabilidade legal pelo passivo ambiental. A irrigaÃÃo pÃblica no semiÃrido brasileiro tem gerado como subproduto a degradaÃÃo dos solos por sais, formando um passivo ambiental, cuja responsabilidade legal da reversÃo à do poder pÃblico. Para quantificar a extensÃo e o custo da reversÃo do dano ambiental, inicialmente, aplicou-se um questionÃrio aos agricultores irrigantes para analisar o significado que eles dÃo aos problemas relacionados com a irrigaÃÃo, com a Ãgua de irrigaÃÃo e com a degradaÃÃo dos solos. Posteriormente, utilizou-se um sensor de induÃÃo eletromagnÃtica para medir a condutividade elÃtrica no solo, estimando-se o total de sais solÃveis em sua soluÃÃo. Os valores da condutividade elÃtrica aferidos pelo sensor nortearam a coleta de amostras de solo para fins de anÃlise fÃsica e quÃmica, procedendo-se à identificaÃÃo das Ãreas degradadas por sais. Com a definiÃÃo da extensÃo dos danos ambientais, levantaram-se os valores de produtividade das principais culturas e o valor bruto da produÃÃo agrÃcola, para aferir os custos da reversÃo do passivo ambiental. Os resultados demonstraram uma hipossuficiÃncia financeira e tÃcnica dos agricultores irrigantes; que a degradaÃÃo ambiental por sais atinge 67,27% da Ãrea do perÃmetro irrigado. Conclui-se que, em decorrÃncia dos aspectos de solidariedade, a responsabilidade civil objetiva na reparaÃÃo do dano ambiental provocado pela irrigaÃÃo à do poder pÃblico.
The research has as a physical basis the Curu Pentecoste Irrigated Perimeter, under jurisdiction of the Departamento Nacional de Obras Contra as Secas (National Department of Works to Combat Drought) and as an objective quantify the extent, the cost of reversal and legal responsibility for the environmental liability. The public irrigation in the Brazilian semi-arid has generated salt-induced soil degradation as a by-product, originating a legal liability, and its legal responsibility lies with the state authority. To quantify the extent and cost of reverting the environmental damage, initially, a survey was conducted among irrigating farmers to analyze the meaning they give to the problems related to the irrigation, the water used in irrigation and the degradation of the soil. Beforehand an electromagnetic induction sensor was used to measure the electrical conductivity in the soil, estimating the total of soluble salts in its solution. The electrical conductivity values obtained by the sensor oriented the collection of soil samples for the purposes of physical and chemical analyses, proceeding to the identification of the areas degraded by salt. With the definition of the extent of the environmental damage, the values of the main crops and the gross value of the agricultural production were collected to assess the costs of reverting the environmental liability. The results showed financial and technical insufficiencies of the irrigating farmers; that the environmental degradation by salt reaches 67,27% of the irrigated perimeter. In conclusion, as a result of the solidarity aspects, the strict civil liability in repairing the environmental damage caused by irrigation lies with the state authority.
15
Lenis, Julian Mario. "Physiological traits underlying differences in salt tolerance among glycine species." Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/5646.
Повний текст джерелаАнотація:
Thesis (M.S.)--University of Missouri-Columbia, 2008.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 13, 2009) Includes bibliographical references.
16
Wearing, Cameron. "Sodicity and soil microstructure /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18523.pdf.
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17
Ali, Abdul-Mehdi Saleh. "Reactions of urea phosphate in calcareous and alkaline soils: Ammonia volatilization and effects on soil sodium and salinity." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184694.
Повний текст джерелаАнотація:
Nitrogen (N) loss in the form of volatilized ammonia (NH₃) is a considerable problem when ammonium (NH₄⁺) forming fertilizers are applied to calcareous or alkaline soils. Large areas of agricultural land, contain alkalinity and salinity problems, are potentially suitable for crop production with little alteration. This study was conducted to determine and compare the effectiveness of urea phosphate (UP) in reducing soil alkalinity and NH₃ loss. The volatilization of NH₃ from UP and urea (U) was studied on 3 selected soils (Hayhook SL, Laveen L and Latene L) using an aeration system. Urea phosphate and U were each applied at rates of 0, 50, 100 and 200 ppm-N either to the surface dry or in solution or mixed with the soil. The volatilized NH₃ was trapped in sulfuric acid, sampled periodically and analyzed for N using the semi microkjeldahl distillation apparatus. The effect of UP, Sulfur-Foam (SF), Phosphuric Solution (PHP) and a mixture of SF and UP (Mix) on leaching soil sodium (Na) and salinity was also studies on two soils (Pima L and Crot CL) in columns. Each of these amendments was applied at a rate of one and two equivalent amounts of the exchangeable Naₑₓ. The highest N loss in the form of NH₃ occurred when U was applied to Hayhook soil. However, UP applied to Hayhook soil (neutral to acidic, coarse textured and low CaCO₃ content) resulted in the lowest NH₃-N loss. Less NH₃-N loss was found from U application to Laveen and Latene soils (fine textured with higher CaCO₃ content) than with Hayhook soil. The general trend was higher N loss, in the form of volatilized NH₃, with surface application dry or in solution than when mixed with the soil. This trend showed an increase in the amount of volatilized NH₃ with increasing rate of N application. Urea phosphate was as effective as PHP or Mix (acid containing fertilizers) treatments in reducing soil salinity and alkalinity in Pima and Crot soils. No difference was found between rates of application (1 and 2 equivalent amount of Naₑₓ) except for soil pH. A similar trend in the decrease in soil salinity was found to that of the pH which was in the order PHP, UP, Mix, SF and control treatments. No significant difference was found between SF and control treatments in all parameters. No significant difference was found between treatments for exchangeable Ca. This was affected by the Ca compounds present in the soil. Generally, UP is a potential fertilizer for supplying N and phosphorus (P) as plant nutrients, reducing NH₃ volatilization, and can be used as a soil amendment to control soil salinity and alkalinity.
18
McCarthy, Alan John. "Landcare : a means of sustaining viticulture in the Barossa Valley /." Title page, table of contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09ENV/09envm1228.pdf.
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19
Moreau, Sophie. "The detection and delineation of saline/alkali soils in Cochabamba department Bolivia : a comparison of field survey methods with remote sensing using landsat MSS data." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61929.
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20
Sultan, Khawar University of Ballarat. "Distribution of arsenic and heavy metals in soils and surface waters in Central Victoria (Ballarat, Creswick and Maldon)." University of Ballarat, 2006. http://archimedes.ballarat.edu.au:8080/vital/access/HandleResolver/1959.17/12767.
Повний текст джерелаАнотація:
"Three sampling campaigns were conducted in the Ballarat, Creswick and Maldon areas. The sampling area is part of the Golden Triangle region where significant gold-mining activities took place from the 1850s to the present day. [...] Locations were chosen to evaluate arsenic distribution in soils, surface waters and plants in different environments. Easy access to sampling locations allowed detailed scientific sampling, especially in the seasonality study. The different range of environments such as agricultural, state forest, mining, urban and rural provided an opportunity to compare the concentrations of arsenic and other elements in the study area. The study of the three selected areas combined provided further understanding of possible exposure and pathways through which arsenic can get into the food chain. "The objective of the study is to measure levels of heavy metals/metalloids in soils, water and plants in various environments, identify whether the heavy metals/metalloids are mobile and bioavailable and understand the importance of clays and oxide complexes in the fixation of metals."Doctor of Philosophy (PhD)
21
Sultan, Khawar. "Distribution of arsenic and heavy metals in soils and surface waters in Central Victoria (Ballarat, Creswick and Maldon)." University of Ballarat, 2006. http://archimedes.ballarat.edu.au:8080/vital/access/HandleResolver/1959.17/15387.
Повний текст джерелаАнотація:
"Three sampling campaigns were conducted in the Ballarat, Creswick and Maldon areas. The sampling area is part of the Golden Triangle region where significant gold-mining activities took place from the 1850s to the present day. [...] Locations were chosen to evaluate arsenic distribution in soils, surface waters and plants in different environments. Easy access to sampling locations allowed detailed scientific sampling, especially in the seasonality study. The different range of environments such as agricultural, state forest, mining, urban and rural provided an opportunity to compare the concentrations of arsenic and other elements in the study area. The study of the three selected areas combined provided further understanding of possible exposure and pathways through which arsenic can get into the food chain. "The objective of the study is to measure levels of heavy metals/metalloids in soils, water and plants in various environments, identify whether the heavy metals/metalloids are mobile and bioavailable and understand the importance of clays and oxide complexes in the fixation of metals."Doctor of Philosophy (PhD)
22
Entus, Jonathan. "Use of time domain reflectometry to monitor water content and electrical conductivity of saline soil." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0032/MQ64350.pdf.
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23
King, Lyle A. "Land application with saline-sodic coalbed natural gas co-produced waters in Wyoming's Powder River Basin impacts to soil and biological properties /." Laramie, Wyo. : University of Wyoming, 2006. http://proquest.umi.com/pqdweb?did=1221694361&sid=3&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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24
Sessoms, Holly Nicol. "Water use potential and salt tolerance of riparian species in saline-sodic environments." Thesis, Montana State University, 2004. http://etd.lib.montana.edu/etd/2004/sessoms/SessomsH0805.pdf.
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25
Wang, ShuHong. "Soil substrate selection for urban trees under deicing salt and compaction conditions." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82446.
Повний текст джерелаАнотація:
The effects of high sodium chloride (NaCl) levels on Na and nutrient retention of three soil substrates and on littleleaf linden growth in different soil substrates were studied in the laboratory and the greenhouse, within the framework of a substrate selection program for trees planted in downtown Montreal. In addition, the effects of the structural soil (SS) compaction were studied in the first greenhouse experiment. The first greenhouse experiment was established in a factorial arrangement of four soils x four salt levels in a completely randomized design with five replicates. The four soil types were (1) L with a bulk density (BD) of 1.53 g/cm3, (2) LP with a BD of 1.26 g/cm3, (3) SS with a BD of 1.8 g/cm 3 (SS1.8), and (4) SS with a BD of 2.0 g/cm3 (SS2.0). The second greenhouse experiment had a split plot design. Two fertilization levels (with fertilizer and without fertilizer) were randomly arranged as the main plots on ten benches. Within each main plot, the combinations of three NaCl levels (0, 0.5 and 1.0 g NaCl/kg soil) and three soil substrates (L with a BD of 1.40 g/cm3, LP with a BD of 1.13 g/cm 3 and SS2.0) were randomized in the sub-plots. Results from the laboratory leaching experiment indicated that SS had the fastest Na leaching rate and highest Na loss, while LP retained more Na than SS or L. (Abstract shortened by UMI.)
26
Hendrati, Rina Laksmi. "Developing systems to identify and deploy saline and waterlogging tolerant lines of Eucalyptus occidentalis Endl." University of Western Australia. Faculty of Natural and Agricultural Sciences, 2009. http://theses.library.uwa.edu.au/adt-WU2010.0036.
Повний текст джерелаАнотація:
[Truncated abstract] Eucalyptus occidentalis, a timber species from south Western Australia, is highly salt and waterlogging tolerant. Screening identified genotypes tolerant of high salt concentrations and waterlogging. Tolerance at provenance, family and individual level, and how phenotypic performance under salt and waterlogging was inherited was explored to provide a breeding population. Salt and/or waterlogged screening was carried out under controlled conditions up to extreme salt levels to determine tolerance between genotypes. This tank method was shown to produce repeatable results. Seedlings of 30 families from 9 provenances were used for screening. At low salt concentration (up to 300 mM NaCl), differentiation occurred for some traits but in general there was only a slight reduction in growth under salt, and waterlogging alone was not detrimental. At high salt concentration (550 mM) differentiation occurred among genotypes for all traits. Equivalent genotypes were also planted in field trials at three sites, two with medium (583 - 847 mm) and one with low rainfall (372 - 469 mm), in southern Western Australia. Survival was low (<53%) after 9 months due to an exceptional dry season followed by 3 months waterlogging in Kirkwood (38 - 1360 mSm-1), but was high >89% after 33 months in saline fields in Sandalwindy (96 - 976 mSm-1) and Roberts (88 - 1424 mSm-1). Some families were similarly in high rank for height under saline conditions in controlled and field trials. Height had the highest narrow-sense heritability value, especially under controlled saltwaterlogging (0.85) treatment and 20% selection enabled a gain of 8-14% under controlled conditions and in the field. Leaf production under salt was not an inherited trait. Systems were developed to hasten deployment of selected material. Extended daylength (16 h) and paclobutrazol (1 mg a.i/mm stem circumference) stimulated flowering in 2 year-old plants. Clonal propagation was possible. Grafting success varied from 0-100% depending on scion/rootstock provenances. ... There was only a slight reduction in heterozygosity from species level to provenance and family levels, and two superior genotypes maintained high diversity. v Crossing was possible using one stop pollination of cut immature styles and capsule retention varied from 0-34% and germination rate from 2-96%. Genetic distance between parents was correlated with seed set and offspring fitness. Wider genetic distances increased capsule retention, seed germination and seedling survival. Under 500 mM salt-waterlogging, offspring heights were similar when parental genetic distances were similar. High heritability value for height from ANOVA-REML parental screening was confirmed using parent-offspring regression. Screened superior genotypes, which withstood very high salt concentration, provide a breeding population for further breeding and for plantations under saline regions in low-medium rainfall areas in Western Australia and other parts of the world. These trees provide an economic return in areas where no other plants may survive and an environmental service in potentially reducing waterlogging, salinity and its spread.
27
Attumi, Al-Arbe. "Effect of salt stress on phosphorus and sodium absorptions by soybean plants." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20242.
Повний текст джерелаАнотація:
The radiotracer methodology was combined with the Hoagland solution culture of growing soybean in a greenhouse to investigate the absorptions of phosphorus (P), calcium (Ca), and sodium (Na) as a function of salinity. Salt stress was varied by using zero to 120 mM NaCl. The research was initiated because of a need to increase soybean production in the saline soils of the semi-arid regions of the world. Although P absorption increased with time at each concentration of NaCl, increasing its concentrations ([NaCl]) to 120 mM reduced P uptake considerably. The addition of inorganic P (Pi) to the salt medium improved P absorption significantly (P < 0.0001) in stem, petiole, and roots. Polynomial regressions showed the relationship between 22Na activity and [NaCl] for leaves and petiole to be cubic (R2 = 1) while in the stem a quadratic relationship prevailed. A maximum of P and Na absorption was observed at 40 mM NaCl. The relationship between 32P activity and increasing [NaCl] was linear for the roots (a positive slope) and the stem (a negative slope). 45Ca and 32P dual labelling part of the experiments failed to produce results because an unexpectedly high degree of tissue quenching which prevented from obtaining the minimum counting requirements for separation. Shoot fresh and dry weights decreased linearly with increasing [NaCl] as did the root fresh and dry weights. Leaf chlorophyll content during the last week of the final harvest showed a linear relationship with time. Chlorophyll increased with time linearly when the growth medium contained zero and 40 mM NaCl; whereas a negative slope was obtained for 80 and 120 mM NaCl. It seems that P fertilization of the soil could ameliorate the salt effect. 22 Na uptake results indicated that there is a mechanism for exclusion of Na from soybean plant parts.
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Diaz, Melisa A. "Geochemistry of soils from the Shackleton Glacier region, Antarctica, and implications for glacial history, salt dynamics, and biogeography." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595542667761355.
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Al-Hazzouri, Abbas Ahmad 1949. "Effect of soil salinity and acidity on the germination of Quercus emoryi and Robinia neo-mexicana seeds." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/291761.
Повний текст джерелаАнотація:
The purpose of the study was to determine the effect of four salt concentrations and four acid levels of soil solution on the germination of Quercus emoryi and Robinia neo-mexicana seeds, and to study the effects of the cation concentration changes in solution (Na, Ca, Mg, K) and exchangeable cation concentration. The solution extracts and exchange phases of both soils, salt accumulation in the soil increased by increasing the salinity and acidity of the water applied. Exchangeable sodium was related directly to the SAR of the applied solutions. The soil responded differently to the salty water and acid water. Both soil treatments released Ca, Mg and K to the soil solution from the dissolution of the primary minerals and cation exchange reaction.
30
Haffar, Jinan. "Irrigation water quality criteria for wheat in semi-arid areas of Syria." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29705.pdf.
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31
Mayall, Alison Christina. "Relationship of vegetation to salinity and sodicity in wetland meadows of the Chilcotin region of British Columbia." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24861.
Повний текст джерелаАнотація:
This study investigates the relationships between vegetation and salinity and sodicity in wetland meadows in the Chilcotin region of British Columbia.
Eleven vegetation communities and one group of releves with no vegetation
were identified using cluster analysis. An exchangeable sodium per cent of 15 and an electrical conductivity of 4 mmhos/cm were found to be appropriate boundaries for distinguishing between saline and sodic tolerant and intolerant vegetation communities. Some salt tolerant species and communities occurred in fresh conditions; however, intolerant species and communities were rarely found in saline or sodic conditions. Most meadows have soils that are low in salts, but 20 per cent had a high electrical conductivity and 18 per cent had a high exchangeable sodium per cent.Land and Food Systems, Faculty of
Graduate
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Jacobs, Johan Adolf. "Karakterisering van derivate uit 'n Thinopyrum distichum X tetraploïede rog kruising." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52904.
Повний текст джерелаАнотація:
Thesis (MSc)--University of Stellenbosch, 2002.ENGLISH ABSTRACT: Soil salinity is a major limiting factor of plant and crop growth, because the absorption of water and nutrients is such a complex process while low and moderate salinity are omnipresent. Plant growth is affected negatively if a specific ion concentration exceeds its threshold and becomes toxic. The detrimental effect of soil affected by salt on crop production is increasing worldwide (Tanji, 1990). The level to which plants can tolerate high salinity levels is genetically controlled with several physiological and genetic mechanisms contributing to salt tolerance (Epstein & Rains, 1987). The most effective way of addressing the limitations of crop productivity in saline areas, is the development of salt tolerant varieties. Understanding the genetics of salt tolerance is, therefore, necessary for the development of an effective breeding strategy for salt tolerance. The department of Genetics (US) conducts a wide crosses research programme aiming to transfer genes for salt tolerance to wheat and triticale. The donor species, Thinopyrum disticum, an indigenous coastal wheat grass, adapted to high concentrations of salt, was crossed with cultivated rye (Secale cereale) in an attempt to study the genetics of salt tolerance (Marais et al., 1998). The primary goal of this study was to find molecular markers (RAPD and AFLP) which associate with chromosomes promoting salt tolerance for later attempts to transfer the genes to triticale. Seventy clones of secondary hybrids (Th disticum /4x-rye 1/2x-rye) were tested for salt tolerance and showed different levels of salt tolerance. RAPD-marker analyses were used to identify polymorphisms between salt tolerant and salt sensitive plants. Twelve RAPD primers produced clear, analyzable and repetitive polymorphic . fragments that can be used as useful markers. Different AFLP-primer combinations were tested against the genotypes of 15 clones (Marais & Marais 2001, unpublished data) and produced approximately 2000 clearly distinguishable AFLP fragments, of which 54 (3%) were polymorphic fragments. Two RAPD fragments and 4 AFLP fragments that can be used as possible markers for the presence of chromosomes that contribute to salt tolerance were identified. The interpretation of the markers was complicated by heterogeneity among plants with regard to the origin of their chromosomes and the genetic diversity of the rye genome. It is also possible that chromosome re-arrangement took place during backcrossing, which could have complicated the data.
AFRIKAANSE OPSOMMING: Versouting is een van die groot beperkende faktore op plant- en gewasgroei, omdat die opname van water en voedingstowwe so In ingewikkelde proses is en die effek van lae of matige versouting so alomteenwoordig is. Plantgroei word nadelig geaffekteer as 'n spesifieke ioonkonsentrasie sy drempelwaarde oorskry en toksies word. Die nadelige effek van soutgeaffekteerde grond op gewasproduksie, is wêreldwyd aan die toeneem (Tanji, 1990). Die vlak waartoe plante hoë konsentrasies sout kan hanteer is onder genetiese beheer met verskeie fisiologiese en genetiese meganismes wat 'n bydrae maak tot soutverdraagsaamheid (Epstein & Rains, 1987). Die mees effektiewe manier om die beperkinge op gewas produktiwiteit in versoute gebiede te oorkom, is die ontwikkeling van soutverdraagsame variëteite. Begrip van die genetika van soutverdraagsaamheid is dus noodsaaklik vir die ontwikkeling van In effektiewe telingsstrategie. Die departement Genetika (US) bedryf tans 'n wye-kruisings navorsingsprogram waarmee gepoog word om gene vir soutverdraagsaamheid na korog en koring oor te dra. Die skenkerspesie, Thinopyrum disticum, In inheemse strandkoringgras wat aangepas is by hoë konsentrasies sout, is gekruis met verboude rog (Secale cereale) in 'n poging om die oorerwing van soutverdraagsaamheid te bestudeer (Marais et al., 1998). Die hoofdoel van hierdie studie was om molekulêre merkers (RAPD en AFLP) te vind, wat assosieer met chromosome wat soutverdraagsaamheid bevorder en om nuttige merkers daar te stel vir latere pogings om die gene na korog en koring oor te dra. Ongeveer 70 klone van sekondêre hibriede (Th distichum I 4x-rog /I 2x-rog) is onderwerp aan souttoetse en het verskillende grade van soutverdraagsaamheid getoon. RAPDmerker analise is gebruik om polimorfismes te identifiseer tussen soutverdraagsame en soutsensitiewe plante. Twaalf RAPD inleiers het duidelike, ontleedbare en herhalende polimorfiese fragmente opgelewer en moontlike nuttige merkers uitgewys. Verskillende AFLP-inleier kombinasies, wat getoets is teen die genotipes van 15 klone (Marais & Marais, 2001 ongepubliseerde data) het ongeveer 2000 duidelik onderskeibare AFLP fragmente geproduseer, waarvan 54 (3%) polimorfiese fragmente was. Twee RAPD fragmente en 4 AFLP fragmente is geïdentifiseer wat as moontlike kandidaat merkers gebruik kan word vir die identifisering van chromosome wat bydra tot soutverdraagsaamheid . Die interpretasie van die merkers is bemoeilik deur heterogeniteit tussen die plante wat betref die agtergrond van chromosome wat hulle besit en die genetiese diversiteit van die rog genoom. Dit is ook moontlik dat chromosoom herrangskikking plaasgevind het tydens terugkruising, wat die data verder kon kompliseer.
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Owojori, Olugbenga J. (Olugbenga John). "Influence of clay content and salinity on the bioavailability and toxicity of metals (copper and zinc) to soil organisms." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1484.
Повний текст джерелаАнотація:
Thesis (PhD (Botany and Zoology))—University of Stellenbosch, 2009.ENGLISH ABSTRACT: Metal pollution is a problem of increasing global concern. It could arise from industrial activities, as well as pesticide use in agriculture, among other sources. For adequate protection of the soil ecosystem from metal toxicity, the bioavailability of metals must be properly evaluated. A plethora of soil factors affect the bioavailability of metals to soil organisms. These include pH, clay and organic matter contents, salinity among others. While much is known about the influence of some of these parameters, little is known on how clay content and salinity modify the bioavailability of metals to soil organisms. This study investigated the influence of clay content and salinity on partitioning, uptake and toxicity of two essential metals (Cu and Zn) to the earthworm Eisenia fetida in separate laboratory trials. Partitioning of the metals was evaluated with 0.01 M CaCl2, DTPA (di-ethylene-triamine-penta acetic acid), and nitric acid extractions. The metal content of worms was determined by acid digestion, while growth, cocoon production, and mortality were used as endpoints showing toxicity to metals and/or salinity. To test the validity of some of the laboratory results, a field study was undertaken, using the earthworm Aporrectodea caliginosa. Further, the study assessed the effect of salinity, using a battery of laboratory tests (acute, chronic and avoidance tests) with natural and/or artificial soils on four species of organisms (a collembolan Folsomia candida, a potworm Enchytraeus doerjesi and two earthworm species E. fetida and A. caliginosa), representing different feeding patterns and ecological roles in soil. Results showed that with increased clay content, there was increased availability of Cu in the substrate, and increased toxicity to E. fetida as shown by data for mortality and growth. The situation with Zn was less significant at sub-lethal concentrations but much so at lethal concentrations. DTPA and CaCl2 extracted metals revealed changes in partitioning of Cu and Zn with changes in clay content, but this trend was not always consistent. Both DTPA and CaCl2 revealed increased availability of Zn in substrates with increased salinity. Salinity had an additive to synergistic effect with Zn in toxicity to E. fetida. When combined with Cu, salinity also increased the availability of Cu as shown by CaCl2 extracted fraction, and had additive effect on toxicity of Cu to the earthworm. The field study did not succeed in in iv confirming the results of the laboratory study due to confounding role of flooding after heavy rainfall and subsequent leaching of salts and Cu. The results of the experiment on acute and chronic toxicity tests for NaCl on E. fetida showed LC50 of 5436 mg/kg NaCl and EC50 for growth and cocoon production of 4985 and 2020 mg/kg NaCl. These values showed that earthworms might be negatively affected in many soils containing fairly moderate concentrations of salts. Similarly, A. caliginosa could not survive in natural soil containing relatively low salt concentrations (EC = 1.62 dS/m) while reproduction was severely affected at lower EC value of 0.52 dS/m. F. candida and E. doerjesi could survive in the highest salinity soil (EC = 1.62 dS/m) used in this study but their reproduction was severely affected from 1.03 dS/m. Overall, it appears that of all the taxa used, earthworm species were the most sensitive to saline stress and could proof useful in determining ‘safe levels’ of salt in contaminated soils. The results of the avoidance test showed that A. caliginosa avoided both natural and artificial saline soil containing concentrations lower than those avoided by E. fetida. The conclusion is that the influence of clay content and salinity on the bioavailability of Cu and Zn depends largely on the metal in question, but generally speaking, bioavailability and toxicity of the metals were reduced with increased clay content while the opposite was true for salinity. If the species used in this study can be seen as fairly representative of a wide range of soil organisms, the conclusion is that salinisation of soil will be detrimental to most soil organisms at relatively low saline concentrations. Given the role of beneficial soil organisms in several soil processes which in turn contribute to soil fertility and sustainable use of land, it is recommended that any farming practices that may lead to an increase in salt content of agricultural soils should be discouraged.
AFRIKAANSE OPSOMMING: Metaalbesoedeling is ‘n probleem wat toenemende globale kommer veroorsaak. Dit kan ontstaan as gevolg van industriële aktiwiteite sowel as van plaagmiddelgebruik in die landbou en ander bronne.Ten einde die grondekostelsel genoegsaam te beskerm, moet die biobeskikbaarheid van metale ge-evalueer word. ‘n Verskeidenheid van grondfaktore be-invloed die biobeskikbaarheid van metale vir grondorganismes Hulle sluit onder andere in pH, klei, organiese inhoud en soutgehalte. Hoewel heelwat bekend is oor die rol van sommige van hierdie parameters, is min bekend oor hoe klei en soutgehalte die biobeskikbaarheid van metale vir grondorganismes kan modifieer. Hierdie studie het die invloed van kleiinhoud and soutgehalte op die verdeling/partisie, opname en toksisiteit van twee essensiële metale (Cu en Zn) vir die erdwurm Eisenia fetida in afsonderlike laboratoriumproewe ondersoek. Kompartementele verdeling van die metale is geevalueer deur middel van ekstraksie-metodes met 0.01 M CaCl2, DTPA (di-etileentriamien- penta asysnsuur), en salpertersuur ekstraksies. Die metaalinhoud van wurms is bepaal deur suurverterings en spektrofotometriese analises te doen terwyl groei, kokonproduksie en mortaliteit van organismes gebruik is as gevoeligheidseindpunte om toksisiteit van metale en soutgehalte aan te toon. Om die geldigheid van somige van die laboratoriumresultate te toets, is ‘n veldstudie ook onderneem met die erdwurm Aporrectodea caliginosa. Die effek van soutgehalte is verder ondersoek deur ‘n battery van laboratoriumtoetse met vier spesies (‘n kollembool Folsomia candida,’n potwurm Enchytraeus doerjesi en twee erdwurmspesies E. fetida en A. caliginosa), wat verskillende voedingspatrone verteenwoordig. Die resultate het getoon dat met toenmende klei-inhoud was daar ‘n toename in die beskikbaarheid van Cu vir opname vanuit die substraat, asook ‘n toename in toksisiteit vir E. fetida soos deur die gegewens vir mortaliteit en groei uitgewys. Die situasie met Zn was minder betekenisvol by subletale konsentrasies en selfs baie minder so by letale konsentrasies. DTPA en CaCl2 ge-ekstraheerde metale het veranderinge in die partisie/verdeling van Cu en Zn uitgewys met verandering in klei-inhoud, maar die tendens was nie altyd konstant nie. Beide DTPA en CaCl2 ekstraksie het toenemende beskikbaarheid van Zn in substrate uitgewys met toenemende soutinhoud. Soutinhoud het ‘n additiewe/toegevoegde tot sinergistiese vi toksisiteitseffek saam met Zn vir E. fetida. In kombinasie met Cu het soutgehalte ook die geskatte biobeskikbaarheid van Cu verhoog soos uitgewys deur die CaCl2, geekstraheerde fraksie, en het ‘n additiewe effek gehad op die toksisitiet van Cu vir die erdwurm. Die veldstudie kon nie die resultate van die laboratoriumstudie bevestig nie weens die belemmerende rol van vloede na swaar reënneerslae en daaropvolgende uitloging van soute en Cu. Die resultate van die eksperimentele ondersoek na die akute en chroniese effekte van NaCl op E. fetida het ‘n LC50 van 5436 mg/kg NaCl en EC50 vir groei en kokonproduksie van 4985 en 2020 mg/kg NaCl opgelewer. Hierdie waardes het aangetoon dat erdwurms moontlik negatief beinvloed kan word in baie gronde wat ‘n redelike gemiddelde konsentrasie van soute bevat. Soortgelyk kon A. caliginosa nie oorleef in natuurllike grond wat relatief lae soutkonsentrasies bevat het (EC=1.62 dS/m) nie terwyl voortplanting sterk ge-affekteer is by ‘n lae EC waarde van 0.52 dS/m. F. candida en E. doerjesi kon oorleef in die grond met die hoogste soutgehalte (EC= 1.62 dS/m) maar hulle voortplanting is ernstig geknou vanaf 1.03 dS/m. In geheel blyk dit dat van allle taksa wat gebruik is, erdwurms die sensitiefste was vir die stres wat deur soutgehalte veroorsaak is. Die kennis kan nuttig wees in die bepaling van “veilige vlakke” van sout in gekontamineerde gronde. Die resultate van die vermydingstoetse het getoon dat A. caliginosa beide natuurlike en kunsmatig versoute gronde vermy het by konsentrasies wat heelwat laer was as dié wat deur E. fetida vermy is Die gevolgtrekking is dat die invloed van klei en soutgehalte op die biobeskikbaarheid van Cu en Zn grootliks afhanklik is van die metale wat betrokke is en dat biobeskikbaarheid en toksisiteit normaalweg verminder het met verhoogde klei-inhoud, met die teenoorgestelde wat waar was in die geval van soutgehalte. Indien die spesies wat in die studie gebruik is beskou kan word as redelik verteenwoordigend van ‘n wye reeks van grondorganismes, is die gevolgtrekking dat versouting van gronde nadelig sal wees vir meeste grondorganismes, selfs by relatief lae soutkonsentrasies. In die lig van die rol wat nuttige grondorganismes speel in verskeie grondprosesse wat bydraend is tot grondvrugbaarheid en volhoubare gebruik van gronde, word dit aanbeveel dat enige boerderypraktyk wat mag lei tot verhoging van die soutinhoud van landbougronde ontmoedig moet word.
34
Mills, Kevin. "The response of reactive clay soils to wetting agents in the presence of active vegetation." Thesis, Queensland University of Technology, 1998.
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35
Beletse, Yacob Ghebretinsae. "Modelling the soil water and salt balance of planted pastures irrigated with sodium sulphate rich mine effluent." Diss., Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-01182005-083427.
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Boys, Roderick Charles James. "The impact of anthropogenic land-use change on soil organic carbon, Oporae Valley, Lake Tutira, New Zealand : a [thesis] submitted to the Victoria University of Wellington in partial fulfilment of the requirements for the degree of Master of Science in Physical Geography /." ResearchArchive@Victoria e-Thesis, 2008. http://hdl.handle.net/10063/966.
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Engelbrecht, Hendrik Nicolaas. "Water- en soutbalanse van geselekteerde besproeide gronde van die benede Bergrivier opvanggebied." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/50227.
Повний текст джерелаАнотація:
Thesis (MSc)--University of Stellenbosch, 2004.ENGLISH ABSTRACT: A study was conducted between 2000 and 2002 in the lower Berg River catchment of the semi-arid Western Cape Province to investigate the effect of irrigation developments (wheat fields to table grapes) on the quality of the Berg River as well as the sustainability of these developments. This study was necessitated by the mineralisation of both the Breede and Berg River, probably due to irrigation together with the higher pressure on these water resources from the growing demand for fresh water from the Cape Town metropolitan area. Water and Salt balances of two dominant soil patterns (Glenrosa/Swartland and Oakleaf/Hutton soil forms) from the catchment area were monitored at two localities. Vineyard blocks of different ages in the same soil forms were used to study the effect of irrigation over time. The electrical conductivity of the soil water extracts (ECe) was measured three times over depth at the selected sites and the quality of irrigation and drainage return-flow were monitored. Soil water storing capacities of these stony (high rough fragment' fractions) soils were also characterised for more efficient drainage quantity prediction. Glenrosa/Swartland soils showed the highest ECe's (200-400 mx.m") that decreased significantly after four to five years of irrigation and distribution became more uniform over depth. These high salt concentrations were explained due to natural occurrence of salts, mineral weathering and salts from the irrigation water. Oakleaf/Hutton soils showed lower ECe's « 200 nfS.m") but they are subject to the quality of the irrigation water, which is not that constant over years. Localised salt accumulation was observed due to the irrigation method and became more prominent over years. Drainage quantities were under predicted because of the big/high rough fragment fractions and the occurrence of preferential-flow. This prohibited the accurate calculation of the soil water house holding characteristics. It also led to the under calculation of salt return-flow, but it was very evident that the most salt retumflow occurred from the Glenrosa/Swartland soils. Effective irrigation management to achieve and maintain optimal soil water levels and to reduce the negative impact of high ECe's is essential for the sustainability of these irrigation developments. At present it does not seem that the irrigation return-flow is causing dramatic mineralisation of the lower Berg River, but it is a situation that must be monitored as the developments extent and become older (come into production). It seems that irrigation return-flow only has an influence on the quality of the river at the beginning of such a development, but after about three years the influence directly correlates with the quality of irrigation water and mineral weathering.
AFRIKAANSE OPSOMMING: 'n Studie is gedurende die jare 2000 tot 2002 in die benede Bergrivier opvanggebied van die semi-ariede Wes-Kaap Provinsie gedoen om die effek van besproeiingsontwikkelings (koringlande na tafeldruiwe) op die kwaliteit van die Bergrivier se water, asook die volhoubaarheid van besproeiingslandbou te ondersoek. Hierdie studie was genoodsaak deur toenemende versouting van beide die Breede- en Bergrivier, waarskynlik a.g.v. besproeiing, tesarne met groter druk op hierdie waterbronne van wee die groeiende aanvraag na vars water deur die Kaapstadse metropool. Water- en soutbalanse van twee dominante grondpatrone (Glenrosa/Swartland en Oakleaf/Hutton grondvorms) binne die opvanggebied was by twee lokaliteite gemoniteer. Wingerdblokke van verskillende ouderdomme binne dieselfde grondvorms is gebruik om die effek van besproeiing oor tyd te ondersoek. Die elektriese geleiding van die grondwaterekstrak (EGe) was drie maal op verskillende dieptes by geselekteerde persele gemeet en die kwaliteit van besproeiingswater en dreineringsterugvloei was deurgaans gemoniteer. Grondwaterstoringskapasiteite van hierdie klipryke ( hoe 'growwe fragment fraksie) gronde was ook gekarakteriseer vir meer doeltreffende voorspellings van dreineringshoeveelhede. Glenrosa/Swartland gronde het die hoogste EGe's getoon (200-400 mx.m') wat na vier tot vyf jaar se besproeiing aansienlik afgeneem het en meer uniform met diepte versprei was. Die hoe soutkonsentrasies is veroorsaak deur die natuurlike voorkoms van sout in die grond, minerale verwering en sout vanuit die besproeiingswater. Oakleaf/Hutton gronde het laer EGe's getoon « 200 mS.m-I ), maar hierdie gronde se soutinhoud is ook onderhewig aan die kwaliteit van die besproeiingswater en dreinering wat oor jare nie baie konstant was en nog is nie. Gelokaliseerde soutaansarneling tussen wingerdrye is ook waargeneem a.g.v. die besproeiingsmetode en dit word meer prominent oor jare. Dreineringshoeveelhede was onder-voorspel a.g.v. die groot/hoe growwe fragment fraksies en voorkoms van voorkeurvloei, wat die akkurate modellering van grondwaterhuishouding beperk het. Dit het ook daartoe gelei dat soutterugvloei ondervoorspel was, maar dit was duidelik dat die meeste soutterugvloei vanuit die Glenrosa/Swartland gronde plaasvind. Effektiewe besproeiingsbestuur, om optimale grondwaterpeile te handhaaf en om negatiewe effekte van hoe EGe te beperk, is noodsaaklik vir die volhoubaarheid van hierdie tipe besproeiingsontwikkelings. Tans blyk dit nie of besproeiingsterugvloei drarnatiese versouting van die benede Bergrivier veroorsaak nie, maar dit is egter 'n situasie wat deeglik gemoniteer moet word soos wat ontwikkelings uitbrei en ouer word (in produksie kom). Besproeiingsterugvloei het dus net aan die begin van so 'n ontwikkelling 'n invloed op die EG van die rivier, maar na ongeveer drie jaar hou die invloed direk verband met die kwaliteit van die besproeiingswater en minerale verwenng.
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Paes, Jefferson Luiz de Aguiar. "Dispersão e condutividade hidráulica em solos de Pernambuco, em resposta à saturação por sódio e à concentração salina da solução." Universidade Federal de Viçosa, 2012. http://locus.ufv.br/handle/123456789/5482.
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To estimate clay dispersion susceptibility, the water dispersible clay (WDC) is determined in the laboratory. This analysis may not correspond to reality observed in the field, when saline and saline-sodic soils are present, due to the relatively high salt concentration in the soil solution. In addition, results of determinations of saturates hydraulic conductivity (K0) in the laboratory with distilled or deionized water, may also not match the field conditions in these soils. Thus, we determined the dispersed clay (DC) and the K0, in the laboratory using working solutions of different electrical conductivities (EC) in seven representative soils of Pernambuco State, with exchangeable sodium percentage (ESP) set in the range of 5-30%. In the determination of DC was used a factorial arrangement (7x6x5): 7 soils, 6 adjustments in ESP values (5, 10, 15, 20, 25 and 30%) and 5 EC (0, 0.3, 0.6; 0.9 and 1.2 dS m-1). In the K0 assay was used a factorial arrangement (7x3x3): 7 soil, 3 adjustments in ESP values (5, 15 and 30%) and 3 EC (0, 0.6 and 1.2 dS m-1). The adjustment of ESP was performed by saturating the soil with solutions of sodium adsorption ratio (SAR) appropriate. The DC was obtained by stirring a suspension of 400 ml in 500 mL containers, using a Wagner rotary shaker for 16 h, at 50 rpm. The K0 was measured using constant head permeameter. The experimental results show that there was an increase in the values of DC directly related to the increase in ESP and decrease in EC, also resulting in a decrease in the value K0. The response to treatment was more pronounced in soils with higher proportions of active clays compared to those with a strong presence of iron oxides. The presence of more active clay causes reduction in K0 compared to soils with high percentage of oxides. Those soils are more susceptible to K0 variations due to ESP. Also there is a marked influence of water EC used in the analysis or for irrigation. Measurements of WDC and K0, usually associated with problems of infiltration, erosion and deterioration of the soil structure, are generally performed in laboratories with deionized or distilled water, EC close to 0 dS m-1. However, for salt affected soils, the analysis should be carried out with solutions of EC ≠ 0 dS m-1, using values close to the EC of the saturation extract.
Para estimar a tendência à dispersão de argilas, determina-se, em laboratório, o teor de argila dispersa em água (ADA). Essa análise pode não corresponder à realidade no campo em solos salinos e salino-sódicos, em que a solução desses apresenta concentrações relativamente elevadas de sais. Em acréscimo, resultados de determinações da condutividade hidráulica em meio saturado (K0) em laboratório, com água destilada ou deionizada, podem também não corresponder às condições de campo nesses solos. Determinaram-se a argila dispersa (AD) e a K0, em laboratório, utilizando soluções de trabalho de diferentes condutividades elétricas (CE) em sete solos representativos do Estado de Pernambuco, com percentagem de saturação de sódio (PST) ajustada no intervalo de 5-30%. Na determinação da AD, utilizou-se arranjo fatorial (7x6x5): sete solos, seis ajustes nos valores da PST (5, 10, 15, 20, 25 e 30%) e cinco CE (0; 0,3; 0,6; 0,9; e 1,2 dS m-1). No ensaio da K0, usou-se arranjo fatorial (7x3x3): sete solos, três ajustes nos valores da PST (5, 15 e 30 %) e três CE (0; 0,6 e 1,2 dS m-1). O ajuste da PST foi realizado, saturando os solos com soluções de relação de adsorção de sódio (RAS) apropriadas. A AD foi obtida agitando-se 400 mL de suspensão em recipientes de 500 mL, em agitador rotatório Wagner, durante 16 h, a 50 rpm. A K0 foi quantificada por meio de permeâmetros de carga constante. Os resultados experimentais evidenciaram que houve incremento nos valores da AD diretamente relacionado com o aumento da PST e a diminuição da CE na solução de trabalho, resultando também na diminuição nos valores da K0. A resposta aos tratamentos foi mais acentuada nos solos com maiores proporções de argilas ativas frente àqueles com presença marcante de óxidos de ferro. A presença de argilas mais ativas leva à diminuição da K0, quando comparada com solos com maior proporção de óxidos, tornando esses mais susceptíveis a variações de K0, em decorrência da PST, com marcada influência da CE da água eventualmente utilizada na análise ou na irrigação. As determinações da ADA e de K0, geralmente associadas a problemas de infiltração, erosão e degradação da estrutura dos solos, são realizadas em laboratórios com água deionizada ou destilada, de CE próxima de 0 dS m-1; no entanto, para solos afetados por sais, as análises deveriam ser realizadas com soluções de CE ≠ 0 dS m-1, utilizando valores próximos aos do extrato da pasta de saturação.
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Jenkins, Sommer. "Ecophysiological principles governing the zonation of puccinellia (Puccinellia ciliata) and tall wheatgrass (Thinopyrum ponticum) on saline waterlogged land in south-western Australia." University of Western Australia. School of Earth and Geographical Sciences, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0133.
Повний текст джерелаАнотація:
Puccinellia (puccinellia ciliata) and tall wheatgrass (Thinopyrum ponticum) often show ecological zonation in saline landscapes, with puccinellia occurring in less elevated more saline/waterlogged locations, and tall wheatgrass occurring in more elevated less saline/waterlogged locations. The aims of this study were to: (a) characterize the observed ecological zonation at a field site, (b) quantify the effects of variables likely to explain growth differences of the two plants in glasshouse experiments, and (c) identify and compare anatomical and physiological mechanisms that explain these zonation patterns. At an experiment in the field near Kojonup (0522824E, 6244579N), puccinellia was found to colonise the lower more severely salinised and waterlogged zones of the landscape, with tall wheatgrass occupying the higher less affected zones. These differences in zonation were clearly associated with variance in soil salinity and water-table depth. Glasshouse experiments in soil revealed that low pH values, low calcium concentrations and variation in salinity alone did not explain the ecological zonation observed in the field. However, there was a substantial difference in the responses of the two plant species to waterlogging in combination with salinity. Puccinellia grew better under saline waterlogged conditions than tall wheatgrass, which was associated with better regulation of Na+ and K+ under saline/waterlogged conditions than in tall wheatgrass. Under non-saline conditions, waterlogging (hypoxia) decreased shoot weights in puccinellia by 15% and in tall wheatgrass by 20%. Similar growth results were obtained in nutrient solution culture, where waterlogging was simulated by lowering the oxygen in solutions through bubbling with N2 gas. Under saline hypoxic conditions, puccinellia, compared to tall wheatgrass, showed increased growth and maintenance of selectivity of K+ over Na+ across adventitious roots. Solution experiments revealed adaptive traits responsible for conveying better growth and ion maintenance present in puccinellia, but not tall wheatgrass, such as inducement of a barrier to radial oxygen loss in the basal regions of adventitious roots (not previously reported in the literature for puccinellia), formation of root aerenchyma and packing of cortical cells and suberin deposition in hypodermal and endodermal root cell layers. These results should assist in targeting pasture species, and predicting their growth response, in saline and waterlogged landscapes. Further work on examining the genetic material of puccinellia is warranted in order to identify genes that could be transferred into crop plants to convey salt and waterlogging tolerance.
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Cobban, Dale Anne. "Evaluation of three simple hydrosalinity models applied to citrus orchards in the Lower Coerney River irrigation area, Eastern Cape, South Africa." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1005504.
Повний текст джерелаАнотація:
Three hydrosalinity models of different complexity were evaluated against data from selected citrus orchards in the Lower Coerney River irrigation area. These models were statistically compared with field data, and found to vary in accuracy of output predictions. The simplest model, the LEACHING REQUIREMENT (LR) model, has the lowest data input requirements and produces output predictions that correlate with up to 93% of the variance in measured data. SODICS, which is theoretically more detailed and requires a greater level of detail in input, produces predictions of an accuracy equivalent to the LR model. The PEAK model was assessed in two parts, the PEAKM module simulating soil moisture and soil moisture movement was able to predict variations in moisture up to 99% of the time. The PEAKD module, which predicts solute concentrations was less effective in replicating real world conditions
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Volschenk, Theresa. "The effect of saline irrigation on selected soil properties, plant physiology and vegetative reproductive growth of Palsteyn appricots (Prunus armeniaca L.)." Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/1196.
Повний текст джерелаАнотація:
Thesis (PhD (Soil Science))--University of Stellenbosch, 2005.Approximately 45% of apricot tree plantings in South Africa are centered on Montagu, Koo and Barrydale in the Little Karoo. Below average production in this area could be ascribed to the deteriorating water quality of the Breede River and highly saline groundwater from boreholes which provide this area with irrigation water. Profit margins for farmers are such that decreased yields cannot be tolerated. Correct management of low quality water could improve production and net farm income and could decrease irrigation return flow into the river system. The objective of this work was to establish whether international water quality guidelines for apricot are applicable under a different set of climatic conditions for a locally important cultivar and to revise guidelines if necessary for the management of irrigation with saline water. A drainage lysimeter was used to evaluate the effect of saline irrigation on apricot (Prunus armeniaca cultivar Palsteyn) trees over a period of four years at Stellenbosch (S33° 55’; E18° 53’) in the Western Cape.
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HASSAN, HESHAM MAHMOUD. "ESTIMATION OF EVAPOTRANSPIRATION AND IRRIGATION UNIFORMITY FROM SUBSOIL SALINITY (ARIZONA)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/188001.
Повний текст джерелаАнотація:
Irrigation uniformity, efficiency, leaching fraction, salt and water ages, and evapotranspiration rate were estimated from subsoil salinity data for three cotton fields in Arizona. The estimation of these parameters was based on the assumption of steady-state water and salt flow through the crop root zone. The levels of salt concentration in the irrigation water were 21.3, 11.5, and 11.6 meq/L for Fields 1, 2, and 3, respectively. Two of these fields were furrow irrigated, and the third was subsurface drip irrigated. Each field was sampled for salt concentrations to a depth of 1.5 m at 10-15 sites. A total of 514 soil samples were collected. Significantly lower salt concentrations were observed in the soil profiles in Fields 1 and 2 compared to Field 3, but lower variations in the salt concentrations were observed in Field 3 compared with Fields 1 and 2. These variations in salt concentration could be due to restricted water movement within the soil profile caused by stratified soil. Since a soil-water extract model indicated little or no chemical precipitation of salt within the soil profile, there was no need to correct the data for chemical effects. The calculated irrigation uniformity was highest in Field 3 and lowest in Field 1. This may be related to more accurate land leveling in field 2 than Field 1. The irrigation efficiencies were 83.0%, 89.0%, and 80.0% for Fields 1, 2, and 3, respectively. The correlation coefficient between the ages of salt and water was 0.98, 0.99, and 0.97 for Fields 1, 2, and 3, respectively. Leaching fraction was highest in Field 3 and lowest in Field 2. Mean actual ET calculated from the Blaney-Criddle method were 372, 314, and 308 mm for Fields 1, 2, and 3, respectively. Mean ET calculated from the salinity data were 1,250, 1,590, and 1,140 mm for Fields 1, 2, and 3, respectively. Statistically significant correlation coefficients were, however, found between both methods of estimating ET. These values were 0.97, 0.86, and 0.93 for Fields 1, 2, and 3, respectively.
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Hengari, Simeon Ngaitungue. "The growth response of Eucalyptus grandis x E. camaldulensis to salt stress, ectomycorrhizae and endomycorrhizae double colonisation /." Thesis, Link to the online version, 2007. http://hdl.handle.net/10019/390.
Повний текст джерела
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Farrell, Claire. "Leaf-litter and microsite on seedling recruitment in an alley-planted E. sargentii and Atriplex spp. saline agricultural system." University of Western Australia. School of Plant Biology, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0110.
Повний текст джерелаАнотація:
[Truncated abstract] In order to assess the sustainability of mixed plantings on saline land, this thesis examined the importance of leaf-litter trapping and microsites on recruitment in a salt affected alley-belted (tree/shrub) agricultural system in Western Australia. Located in the low rainfall region (MAR <330 mm) of the wheatbelt, the 60 ha site consists of concentric rows of Eucalyptus sargentii trees with mounded (6 - 11 cm high) 10 -15 m inter-rows of Atriplex spp. Sustainability of this system and fulfilment of productive and ameliorative functions is dependant on successful recruitment (perennials). Although the present study site was conducted on farmland in a Mediterranean-type climate, low annual rainfall and spatial arrangement of perennial shrubs and trees, allow useful comparisons to be made with naturally occurring banded semi-arid systems and vice-versa. Of key interest were leaf-litter redistribution and trapping by tree and shrub rows and whether litter-cover/microsites facilitated/interfered with seedling recruitment (establishment, growth and survival). Litter from the tree row, redistributed by prevailing winds and rain, accumulated adjacent to saltbush seeding mounds, creating a mosaic of bare and littered areas across the site (total litter 10 t/ha over 22 months). Accumulated litter was hypothesized to differentially influence seasonal soil abiotic parameters (depending on litter-cover density) including; salinity, water availability, infiltration rates, water repellency and temperature. These abiotic conditions were also hypothesized to vary between tree and shrub microsites. Biotically, recruitment at this site was also hypothesized to be determined by interactions (positive and negative) between perennial components and understorey annuals/perennial seedlings. Accumulation of litter and resultant heterogeneity was influenced by shrub morphology, microtopography, wind direction and distance from litter source, with increased litter on the leeward sides of hemispherical Atriplex undulata shrubs and shrubs closest to tree rows. ... The importance of tree/shrub microsites varied seasonally, with no influence in winter due to moderate temperatures and increased water availability. In warmer months saltbush mid-row microsites were most favourable for seedling recruitment due to moderate litter-cover; reducing salinity, temperatures and increasing infiltration; and reduced root-competition/shading by the tree row. Tree microsites also directly inhibited seedling recruitment through increased salinities and water repellency. However, trees also indirectly facilitated recruitment in adjacent areas through provision of leaf-litter. As litter-trapping and recruitment patterns at this site mirror those found in semi-arid natural and artificial systems, the results of this study provide useful insights into creating appropriate mimics of low rainfall natural banded woodland and chenopod shrublands. Saltbush seeding mounds, shrub morphology and litter were key components for litter trapping and recruitment heterogeneity at this site. In this tree/shrub alley planting, where litter quantities directly influence vegetation cover densities, future saline plantings need to consider appropriate tree/shrub row spacings and orientation for efficient resource (seeds, litter and water) capture.
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McDonald, Kathi. "Variation in morphology, salinity and waterlogging tolerance and resource allocation in strawberry clover (Trifolium fragiferum L.) : implications for its use in mildly saline soils in southern Australian farming systems." University of Western Australia. School of Plant Biology, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0105.
Повний текст джерелаАнотація:
[Truncated abstract] In southern Australian farming systems the replacement of deep-rooted perennial native vegetation with shallow-rooted annual crops and pastures has resulted in rising groundwater tables and an increased incidence of dryland salinity. It has been suggested that to address this issue by restoring hydrological balance, large areas of agricultural land need to be vegetated with perennial plants. One of the most agriculturally productive ways to do this is to introduce perennial pastures, both into upslope groundwater
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Cleland, Jonelle. "Western Australia's salinity investment framework : a study of priority setting in policy and practice." University of Western Australia. School of Agricultural and Resource Economics, 2008. http://theses.library.uwa.edu.au/adt-WU2009.0120.
Повний текст джерелаАнотація:
In March 2002 the Western Australian Minister for Environment and Heritage adopted a policy framework to guide investment decisions on salinity management. Promoted as Western Australia's Salinity Investment Framework (or the SIF), it offered a set of principles for prioritising investment decisions that were generally grounded in economic theory. This represented a significant landmark in terms of the government's appreciation of the scale of salinity problem and its acknowledgement that a full turnaround in the situation was beyond the reach of both volunteers and the public purse. The evolution of the SIF policy, including an initial trial in the Avon Basin, provided an opportunity to evaluate pre-policy processes; observe policy on the run; and test stakeholder reactions to the investment principles embodied in the the SIF, as well as their reaction to its implied outcomes. The intention of the study was to highlight any barriers standing in the way of effectively implementing a policy to prioritise investments in salinity management and identify any novel approaches developed in an attempt to overcome them. The evaluation was multifaceted to incorporate retrospective and prospective modes of inquiry. The retrospective investigation involved the construction of a series of policy narratives using evidence from notes and minutes taken at SIF meetings, as well as other formal and informal documents. It systematically captured the influence of key people, events and decisions on the SIF up until June 2008. This evaluation highlighted the impact of (1) policy entrepreneurs; (2) time lags; (3) vertical silos, and (4) priority setting hierarchies. The prospective investigation involved the execution of a community survey featuring attitudinal questions, paired comparisons and a choice modelling experiment. The survey involved 269 personal interviews with rural landholders, townspeople and landcare officers across the Avon Catchment. It captured perceptions towards past funding strategies and proposals for future allocations and explored the nature of priority setting decisions in relation to trade-offs between: (1) the mix of assets protected; (2) the degree of risk; (3) the level of community involvement in the decision, and (4) the distribution of benefits. This evaluation highlighted the importance of (1) incentives and disincentives for change; (2) awareness of priority setting concepts; (3) the capacity of regional bodies; and (4) elements perceived to be crucial in priority setting.
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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.
Повний текст джерелаАнотація:
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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Камаєва, І. О. "Екологічна безпека гірничо-хімічних виробництв в умовах аеротехногенного забруднення довкілля (на прикладі Калуського промислового району)". Thesis, Івано-Франківський національний технічний університет нафти і газу, 2009. http://elar.nung.edu.ua/handle/123456789/4306.
Повний текст джерелаАнотація:
Дисертація присвячена вивченню проблеми аеротехногенного забруднення навколишнього середовища в районі дії гірничо-хімічних підприємств. У дисертаційній роботі вирішено важливе науково-практичне завдання встановлення особливостей формування екологічної небезпеки гірничо-хімічних виробництв та виявлення масштабів їх впливу на довкілля, а також розроблено природоохоронні заходи та засоби зменшення впливу відходів калійних виробництв на довкілля.
Побудовано математичну модель розсіювання шкідливих речовин в атмосфері з врахуванням висоти джерела викиду, швидкості вітру, густини та розміру частинок. Наведено результати експериментальних досліджень аеротехногенного забруднення зони аерації солевідвалами Домбровського кар’єру та обґрунтовано явище підвищення водопроникності глинистих ґрунтів у випадку зростання концентрації сольового фільтруючого розчину. Для спрощеної моделі балансу маси речовини, розчиненої в елементі водоносного пласта, запропоновано методику визначення рівня забруднення підземних вод на основі розрахунку концентрації мігруючої речовини. Винайдено спосіб очищення повітря від пилу, який буде використано у процесі реконструкції калійних виробництв ВАТ “Гірхімпром”.Диссертация посвящена изучению проблемы аэротехногенного загрязнения окружающей среды в районе воздействия горно-химических предприятий. В диссертационной работе решена важная научно-практическая задача по установлению особенностей формирования экологической опасности горнохимических предприятий и выявлению масштабов их влияния на элементы окружающей среды, а также разработаны природоохранные мероприятия и средства, уменьшающие влияние отходов калийных производств на окружающую среду. Рассмотрена концепция изучения процесса распространения выбросов промышленных предприятий в приземном слое атмосферы. Построена математическая модель рассеивания выбросов, а также получены зависимости дальности полета частиц от их плотности, размера, высоты источника выбросов и скорости ветра. Рассматривая солеотвалы Домбровского карьера как источник вредных выбросов, также построена математическая модель пылевого рассеивания под воздействием силы ветра. Разработанные математические модели рассеивания вредных веществ позволяют оперативно оценить масштабы загрязнения территорий, подвергшихся аэротехногенному влиянию не только при лимитированных выбросах, но и при аварийных. Приведены результаты экспериментальных исследований аэротехногенного загрязнения зоны аэрации соле-отвалами Домбровского карьера. Изучено и обосновано явление повышения водопроницаемости глинистых почв при увеличении концентрации солевого фильтрующего раствора. Для упрощенной модели баланса массы вещества, растворенного в элементе водоносного пласта, предложена методика определения уровня загрязнения подземных вод путем расчета концентрации мигрирующего вещества. Для эффективного подавления пыли на территории дробильно-сортировочного комплекса разработана автоматизированная установка и проведены ее испытания с использованием поверхностно-активных веществ. Изобретен способ очистки воздуха от пыли воздушно-механической пеной высокой кратности при транспортировке и переработке калийных руд. Этот способ будет использован при реконструкции калийных производств ОАО “Гирхимпром”.
Dissertation is devoted to the investigation of the aerotechnogenical contamination problem in the area of mine-chemical enterprises activity. In the dissertational work the important scientific-practical task of establishment features of forming ecological danger by mine-chemical productions and size detection of their influence on the environment is decided, and also the nature protections measures and means of decrease the potassiums production wastes influence on the environment are elaborated. The mathematical model of the harmful matters dispersion in the atmosphere, taking into account the height of ejection source, speed of wind, density and size of particles, is constructed. The results of experimental researches of aerotechnogenical contamination of the environment by salt dumpes of Dombrov quarry are presented and the phenomenon of increasing water permeability of clay soils with growing concentration of salt filtering solution is substantiated. For the simplified model of the admixture mass balance, placed in the water stratum element, the methodics for definition the pollution level of the underground water basing on the estimation of the concentration the migrated admixture, is suggested. The method for cleaning air from dust is invented. This method will be introduced at the reconstruction of potassiums productions OAC “Girhimprom”.
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Asghari, Hamid Reza. "Effects of arbuscular-mycorrhizal fungal colonization on management of saline lands." Thesis, 2004. http://hdl.handle.net/2440/37965.
Повний текст джерелаАнотація:
The overall aim of the research presented in this thesis was to evaluate the importance of arbuscular-mycorrhizal ( AM ) colonization of plants in management of saline lands. Some aspects of application of AM fungi in revegetation of saline lands are also reported. Effects of AM pre-inoculation on mycorrhiza-responsive and non-responsive plant growth and establishment were evaluated under glasshouse conditions. The advantages of mycorrhizal fungal inoculation in increasing plant salinity tolerance and establishment in saline conditions were related to the responses of host species to AM fungi. Pre-inoculation with Glomus intraradices increased plant growth, nutrient uptake and establishment of mycorrhiza responsive Trifolium subterraneum in saline conditions, but non-mycorrhiza responsive Festuca arundinacea did not get growth benefits from AM in saline conditions. The main mechanism underlying increased plant growth and establishment in saline conditions in mycorrhiza responsive plants was increased plant nutrient uptake, particularly phosphorus ( P ) , at an early growth stage. The improvement could be explained by higher soil volume exploration by hyphae and / or roots, faster nutrient uptake and microbial changes in the soil rhizosphere.
AM inoculation and P application effects on salinity tolerance were compared in Trifolium subterraneum. Application of P increased plant growth and salinity tolerance in saline conditions, but AM inoculation increased nutrient uptake and plant salinity tolerance more efficiently than P application. Effects of salinity on AM colonization of chenopods were investigated under glasshouse conditions. Salinity had no effects on AM colonization of Atriplex nummularia, but AM inoculation increased plant growth and nutrient uptake. The growth improvement was attributed to benefits from low AM colonization, and changes in bacterial community composition in the rhizosphere. Roles of AM fungi in influencing P leaching from soil were investigated in experiments with repacked cores under both non-saline and saline conditions. Increased plant size via AM inoculation significantly decreased P leaching in the soil profile under both non-saline and saline conditions in low P soils. Increased root volume and extension external hyphal network were the main effects of AM fungi in increasing plant size under saline and non-saline conditions, which led to scavenging more P and depleting more soil available P, thereby decreasing P losses via leaching. Application of P increased plant size and decreased P leaching, but on the other hand increased soil available P and decreased AM colonization.Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2004.
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Alfatesh, Ibrahim Yahya. "Sodium, calcium, and magnesium changes in soils upon application of saline-sodic waters." 1986. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1986_240_sip1_w.pdf&type=application/pdf.
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