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1
Esposito, Nicole C. "Soil Nutrient Availability Properties of Biochar". DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1096.
Testo completoAbstract (sommario):
Biochar’s high porosity and negative surface charge allows for numerous soil and plant benefits such as increased water retention, high nutrient availability, and plant growth. By analysing biochar’s effect of all of these factors, a system can be put in place in which soils can be remediated with the proper soil amendments. This report discusses and tests the effects of varying rates of biochar on pH levels, cation exchange capacity, and nutrient exchangeability (of calcium, magnesium, sodium, and potassium) in soil. Corn plants were also grown in soils of varying amendment types and analysed for plant growth and germination to determine soil effects on the plant.
Testing showed significant differences between treatment types in all areas tested except plant germination. A 2:1 ratio of biochar to compost produced the best overall results for the soil used in testing. This treatment maintained acceptable levels of exchangeable nutrients while raising pH and cation exchange capacity, and also raised the plant growth in the soil by 30%. However, for added soil health, gypsum or calcium fertilizer should be added to the soil to remediate low calcium exchangeability. This testing confirmed that biochar does have a strong positive influence on soil and plant health when used in combination with compost.
2
Kraus, Tamara Esther Caroline. "Tannins and nutrient dynamics in forest soils : plant-litter-soil interactions /". For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
Testo completo
3
Ferreira, Francisco Jardelson. "Fertilization rose bushes based on nutrient balance in the soil - plant system". Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=17134.
Testo completoAbstract (sommario):
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoRose is an economically important crop for the national and the international market and due to this fact generates income to the Ceara State. Rose is a demanding crop in relation to fertilizers, requiring knowledge of soil fertility, nutritional plant requirements and nutrients use efficiency to obtain adequate fertilization. Based on the nutritional balance through the use of mechanistic and empirical models, it is possible to develop a system to quantify the plant nutrients demands to achieve a given productivity. This paper aims to establish parameters of a fertilizer and lime recommendation system to rose crop, based on the plant nutritional balance. The experiment was conducted at the company Cearosa in SÃo Benedito - CE. Plants will be collected during five months and once a month, five rose plants from four varieties (Top Secret, Avalanche, Attache and Ambience) As contradictory Airlines plants Were grinded. Samples will be ground and nutrients content will be determined: N, P, K, Ca, Mg, S, B, Fe, Mn, e Zn. Every sampling plant time, were also soil samples collected at two depths (0-20 and 20-40 cm) In which they underwent fertility analysis. To estimate the fertilizer recommendation, the system was be subdivided into requirement subsystem (REQ), which includes the plant nutrients demands, considering the recovery efficiency of the nutrients to be applied and a rate to achieve the "sustainability" criteria and the supply subsystem (SUP) that comprises the soil nutrient supply. After determining the total REQ and SUP, held -if the nutritional balance, and if the result is positive (REQ> SUP), fertilizers application is recommended and if the result negative or zero (REQ ≤ SUP), fertilizers application is not recommended. The system estimated that there is excess nitrogen and phosphorus fertilization for all cultivars , however , there needs to be supplemental potassium fertilizer . The system estimated that the soil is able to meet the demand of plants for P and Fe for all cultivars , however , there must be supplementary nitrogen fertilizer , potassium . As for micronutrients , the system estimated that there is need for additional fertilizer for Zn in all rosebushes and Mn for the rosebushes "Top Secret " and " Avalnche " , however with very close recommendation the optimal dose , ie equal to zero
A roseira à uma cultura de grande valor no mercado interno e externo, devido a esse fato, as rosas geram benefÃcios para o estado do CearÃ. à uma cultura muito exigente em relaÃÃo à adubaÃÃo, sendo necessÃrios conhecimentos da fertilidade do solo, exigÃncias nutricionais da planta e eficiÃncia na utilizaÃÃo de nutrientes, para obtenÃÃo de uma adubaÃÃo adequada. Partindo a hipÃtese de que conhecendo-se o balanÃo nutricional da cultura, levando-se em consideraÃÃo a demanda de nutrientes pela cultura para alcanÃar uma dada produtividade e o suprimento de nutrientes pelo solo, à possÃvel determinar a quantidade de nutrientes a ser adicionada na fertilizaÃÃo do solo. O presente trabalho tem como objetivo determinar com base no balanÃo de nutrientes solo-planta a quantidade de nutrientes a ser adicionada no solo para cultura da roseira. O experimento foi conduzido na empresa Cearosa, em SÃo Benedito - CE, as plantas foram coletadas durante cinco meses, sendo uma vez por mÃs, amostrando cinco plantas aleatÃrias, de quatro cultivares de rosas: (Top Secret, Avalanche, Attache e Ambience). As partes aÃreas das plantas foram moÃdas e mineralizadas para determinaÃÃo dos teores dos nutrientes: N, P, K, Ca, Mg, S, B, Fe, Mn e Zn. Simultaneamente a coleta de plantas, tambÃm foram coletadas amostras de solo em duas profundidades, camada de 0 a 20 e de 20 a 40cm. Na qual foram submetidas à anÃlise de fertilidade. Para estimar a recomendaÃÃo de adubaÃÃo o sistema foi subdividido em: subsistema requerimento (REQ), que contempla a demanda de nutrientes pela planta, considerando a eficiÃncia de recuperaÃÃo dos nutrientes a serem aplicados, alÃm de uma dose que atende ao critÃrio de âsustentabilidadeâ e o subsistema suprimento (SUP), que corresponde à oferta de nutrientes pelo solo. ApÃs a determinaÃÃo do REQ total e SUP total, realizou -se o balanÃo nutricional, no qual se apresentar resultado positivo (REQ > SUP), recomenda-se a aplicaÃÃo de fertilizantes, e negativo ou nulo (REQ ≤ SUP), nÃo serà recomendado aplicar fertilizantes. O sistema estimou que o solo à capaz de suprir a demanda das plantas para P e Fe para todas as cultivares, no entanto, à necessÃrio que haja complementaÃÃo de adubaÃÃo nitrogenada, potÃssica. Assim como para os micronutrientes, o sistema estimou que hà necessidade de complementaÃÃo de adubaÃÃo, para Zn em todas as roseiras e Mn para as roseiras âTop secretâ e âAvalncheâ, no entanto com a recomendaÃÃo bem prÃximos a dose ideal, ou seja, igual a zero
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Barthelemy, Hélène. "Herbivores influence nutrient cycling and plant nutrient uptake : insights from tundra ecosystems". Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-120191.
Testo completoAbstract (sommario):
Reindeer appear to have strong positive effects on plant productivity and nutrient cycling in strongly nutrient-limited ecosystems. While the direct effects of grazing on vegetation composition have been intensively studied, much less is known about the indirect effect of grazing on plant-soil interactions. This thesis investigated the indirect effects of ungulate grazing on arctic plant communities via soil nutrient availability and plant nutrient uptake. At high density, the deposition of dung alone increased plant productivity both in nutrient rich and nutrient poor tundra habitats without causing major changes in soil possesses. Plant community responses to dung addition was slow, with a delay of at least some years. By contrast, a 15N-urea tracer study revealed that nutrients from reindeer urine could be rapidly incorporated into arctic plant tissues. Soil and microbial N pools only sequestered small proportions of the tracer. This thesis therefore suggests a strong effect of dung and urine on plant productivity by directly providing nutrient-rich resources, rather than by stimulating soil microbial activities, N mineralization and ultimately increasing soil nutrient availability. Further, defoliation alone did not induce compensatory growth, but resulted in plants with higher nutrient contents. This grazing-induced increase in plant quality could drive the high N cycling in arctic secondary grasslands by providing litter of a better quality to the belowground system and thus increase organic matter decomposition and enhance soil nutrient availability. Finally, a 15N natural abundance study revealed that intense reindeer grazing influences how plants are taking up their nutrients and thus decreased plant N partitioning among coexisting plant species. Taken together these results demonstrate the central role of dung and urine and grazing-induced changes in plant quality for plant productivity. Soil nutrient concentrations alone do not reveal nutrient availability for plants since reindeer have a strong influence on how plants are taking up their nutrients. This thesis highlights that both direct and indirect effects of reindeer grazing are strong determinants of tundra ecosystem functioning. Therefore, their complex influence on the aboveground and belowground linkages should be integrated in future work on tundra ecosystem N dynamic.
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Visser, Saskia M. "Modelling nutrient erosion by wind and water in northern Burkina Faso /". Wageningen : Wageningen University and Research Centre, 2004. http://www.mannlib.cornell.edu/cgi-bin/toc.cgi?5046904.
Testo completo
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Mills, Carolyn Lesley. "The nutrient economy of grazed grassland". Thesis, Queen's University Belfast, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361226.
Testo completo
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Sika, Makhosazana Princess. "Effect of biochar on chemistry, nutrient uptake and fertilizer mobility in sandy soil". Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20272.
Testo completoAbstract (sommario):
Thesis (MScAgric)--Stellenbosch University, 2012.ENGLISH ABSTRACT: Biochar is a carbon-rich solid material produced during pyrolysis, which is the thermal degradation of biomass under oxygen limited conditions. Biochar can be used as a soil amendment to increase the agronomic productivity of low potential soils. The aim of this study was to investigate the effect of applying locally-produced biochar on the fertility of low-nutrient holding, sandy soil from the Western Cape, and to determine the optimum biochar application level. Furthermore, this study investigates the effect of biochar on the leaching of an inorganic nitrogen fertilizer and a multi-element fertilizer from the sandy soil. The biochar used in this study was produced from pinewood sawmill waste using slow pyrolysis (450 °C). The soil used was a leached, acidic, sandy soil from Brackenfell, Western Cape. In the first study, the sandy soil mixed with five different levels of biochar (0, 0.05, 0.5, 0.5 and 10.0 % w/w) was chemically characterised. Total carbon and nitrogen, pH, CEC and plant-available nutrients and toxins were determined. The application of biochar resulted in a significant increase in soil pH, exchangeable basic cations, phosphorus and water holding capacity. A wheat pot trial using the biochar-amended soil was carried out for 12 weeks and to maturity (reached at 22 weeks). The trial was conducted with and without the addition of a water-soluble broad spectrum fertilizer. Results showed that biochar improved wheat biomass production when added at low levels. The optimum biochar application level in the wheat pot trial was 0.5 % (approximately 10 t ha-1 to a depth of 15 cm) for the fertilized treatments (21 % biomass increase), and 2.5 % (approximately 50 t ha-1 to a depth of 15 cm) for unfertilized treatments (29 % biomass increase). Since most biochars are alkaline and have a high C:N ratio, caution should be taken when applying it on poorly buffered sandy soil or without the addition of sufficient nitrogen to prevent nutrient deficiencies. In the second study, leaching columns packed with sandy soil and biochar (0, 0.5, 2.5 and 10.0 % w/w) were set up to determine the effect of biochar on inorganic nitrogen fertilizer leaching over a period of 6 weeks. It was found that biochar (0.5, 2.5, and 10.0 % w/w) significantly reduced the leaching of ammonium (12, 50 and 86 % respectively) and nitrate (26, 42 and 95 % respectively) fertilizer from the sandy soil. Moreover, biochar (0.5 %) significantly reduced the leaching of basic cations, phosphorus and certain micronutrients. This study demonstrated the potential of biochar as an amendment of acidic, sandy soils. Our findings suggest that an application rate of 10 t ha-1 should not be exceeded when applying biochar on these soils. Furthermore, biochar application can significantly reduce nutrient leaching in sandy agricultural soils.
AFRIKAANSE OPSOMMING: Biochar is ʼn koolstof-ryke, soliede materiaal geproduseer gedurende pirolise, wat die termiese degradasie van biomassa onder suurstof-beperkte omstandighede behels. Biochar kan gebruik word as ʼn grondverbeterings middel om die agronomiese produktiwiteit van grond te verhoog. Die doel van hierdie studie was om die effek van plaaslike vervaardigde biochar op die vrugbaarheid van die sanderige grond van die Wes-Kaap te ondersoek, en om die optimale biochar toedieningsvlak te bepaal. Verder, het hierdie studie die effek van biochar op die loging van anorganiese stikstof kunsmis en ‘n multi-elementkunsmis op sanderige grond ondersoek. Die biochar wat in hierdie studie gebruik is, is van dennehout saagmeul afval vervaardig d.m.v. stadige pirolise (450 °C). Die grond wat in hierdie studie gebruik is, is ‘n geloogde, suur, sanderige grond van Brackenfell, Wes-Kaap. In die eerste studie, is ‘n chemiesie ondersoek van die sanderige grond wat vermeng met is met vyf verskillende vlakke van biochar (0, 0.05, 0.5 en 10.0 % w/w) uitgevoer. Totale koolstof en stikstof, pH, KUK, en plant-beskikbare voedingstowwe en toksiene is in die grondmengsels bepaal. Die toediening van biochar het ‘n veroorsaak dat die grond pH, uitruilbare basiese katione, fosfor en waterhouvermoë beduidend toegeneem het. ‘n Koringpotproef was uitgevoer vir 12 weke en ook tot volwassenheid (wat op 22 weke bereik was) om die effek van die biochar op die sanderige grond teen die vyf verskillende toedieningsvlakke te bepaal. Daar was behandelings met en sonder die bykomstige toediening van ‘n wateroplosbare breë-spektrumkunsmis. Resultate toon dat die toediening van biochar teen lae vlakke koringbiomassa produksie verbeter. Die optimale biochar toedieningsvlak in die koringpotproef is 0.5 % (omtrent 10 t ha-1 tot ‘n diepte van 15 cm) vir die bemeste behandeling (21 % biomassa toename), en 2.5 % (omtrent 50 t ha-1 na ‘n diepte van 15 cm) vir onbemeste behandelings (29 % biomassa toename). Aangesien die meeste biochars alkalies is en ‘n hoë C:N verhouding besit, moet sorg gedra word wanneer dit op swak-gebufferde of lae N-houdende sanderige gronde toegedien word. Die resultate het aangedui dat die biochar versigtig aangewend moet word om grond oorbekalking te voorkom. In die tweede studie, was kolomme gepak met 2.0 kg van die sanderige grond gemeng met biochar (0, 0.05, 0.5, 2.5 en 10.0 % w/w) om die effek van biochar op die loging die anorganiese stikstof kunsmis oor ‘n tydperk van 6 weke om vas te stel. Daar is gevind dat biochar (0.5, 2.5 en 10.0 % w/w) die loging van ammonium (12, 50 en 86 % onderskeidelik) en nitraat (26, 42 en 95 % onderskeidelik) op sanderige grond aansienliek verminder. Verder, het biochar (0.5 %) die loging van basiese katione, fosfor en mikrovoedingstowwe aansienlik verminder. Hierdie studie het die potensiaal van biochar as verbeteringmiddel van suur, sanderige grond gedemonstreer. Ons bevindinge dui daarop aan dat ‘n toepassing vlak van 10 t ha-1 moet nie oorskry word nie wanneer biochar op hierdie gronde toegedien word. Die toediening van biochar op sanderige grond kan die loging van voedingstowwe aansienlik verlaag.
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Hassan, Khalida Abdul-Karim. "The effect of soil conditions on nutrient availability, nutrient uptake and productivity of spring wheat". Thesis, University of Manchester, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329590.
Testo completo
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Schofield, Hannah Kate. "A biogeochemical study of nutrient dynamics in artificial soil". Thesis, University of Plymouth, 2015. http://hdl.handle.net/10026.1/3766.
Testo completoAbstract (sommario):
Artificial soils have been employed within the Biomes of the Eden Project since its construction in 2000. Produced from sand, bark, composted green waste and lignite clay, these soils were designed to have their nutrient concentrations controlled through careful fertiliser applications. However, following variable environmental conditions, management practices and planting, the soils across the site are performing variably with regard to nutrient retention and storage. Experiments were conducted to assess the performances of an artificial soil in terms of nutrient cycling. This was carried out in three phases: Firstly, soils from the Humid Tropics and Outdoor biomes were sampled and examined, using a range of analytical techniques, to determine the nutrient characteristics of the established artificial soils from across the Eden Project site. This demonstrated that many of the nutrient concentrations of the artificial soils were consistent with those reported for naturally formed soils within comparable environments. All soil samples were of sandy loam texture (ISO 14688-1), with the sand-sized fraction representing > 50 % of the particle size composition. Statistical analyses suggested that management practices had a greater impact on the nutrient characteristics of artificial soils than environmental conditions. Secondly, an artificial soil was produced, following the Eden Project protocol, to examine its performance under controlled environmental conditions. This was packed into 4 columns (1 m height by 110 mm diameter), maintained at 15 ˚C and subjected to an irrigation regime for 52 weeks. Following 26 weeks of irrigation, 2 of the 4 columns were fertilised. Leachate was analysed for dissolved constituents as were solid samples of the fresh soil and of soil samples collected from the columns following 52 weeks irrigation. Leachate concentrations for all nutrients, excepting phosphate, were observed to decline over the irrigation period. Leached phosphate concentrations increased from weeks 0 to 2, and then remained relatively constant. Low nitrogen concentrations within the leachate from weeks 2 to 38 were caused by nitrogen immobilisation within the soil, whilst subsequent mineralisation resulted in increased concentrations from Week 38. Analyses of solid phase constituents determined little variation with depth. Fertiliser application demonstrated a significant (p < 0.05) increase in leachate concentrations for some dissolved organic nitrogen and nitrate, phosphate, magnesium and calcium and a decrease in pH. Fertiliser application observations showed less prominent differences for the extracted and solid phase constituents. Thirdly, biochar was applied to the artificial soil at three concentrations (10 %, 5 % and 2 %) plus a control (0 %), to determine whether biochar application may improve nutrient characteristics of artificial soils. The biochar amended soils were packed into mesocosms and maintained at 15 ˚C for 6 weeks. In general, leachate analyses demonstrated a decrease in nutrient losses to leaching with increasing biochar concentration, highlighting the potential for improved nutrient retention within the soils.
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Collins, Shane. "Residue composition influences nutrient release from crop residues". University of Western Australia. School of Earth and Geographical Sciences, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0171.
Testo completoAbstract (sommario):
[Truncated abstract] A greater adoption of stubble retention, minimum-till and no-till farming practices for the purposes of conserving soil, water and fertility requires a greater understanding of the complexity of physical and chemical interactions between the soil and crop residues. There is currently insufficient knowledge to allow reliable predictions of the effects of different residue types in different environments on soil fertility and crop growth, owing to the many residue characteristics and environmental interactions that have been shown to affect decomposition or nutrient release. The role of fibre and nutrient composition in nutrient release from crop residues, and implications for residue management techniques, were studied. Canola, lupin and field pea residues, obtained from farmland in Meckering and Northam, Western Australia, were separated into upper and basal stems, leaves, and siliques or pods. This was done to provide materials with a wide range of chemical and physical characteristics, and also allowed consideration of differential residue management of plant organs, such as comparing harvested canola siliques and retained canola stubble. Pre-treatment by chopping and/or humidification was applied to residues to provide some information about the processes of nutrient release. Residues were subjected to simulated rainfall to assess nutrient leaching from plant material, and placed on soil in pots in constant-temperature glasshouse conditions to assess decomposition. Amounts and rates of change of residue fibre and nutrients were determined throughout leaching and decomposition. Energy Dispersive X-ray (EDX) microanalysis was used to assess the location of diffusible ions in air-dried residues and the effects of humidification on nutrient positioning and release. ... However, the release of calcium and magnesium depended on the decomposition of the more recalcitrant components such as cellulose and lignin, as supported by microscopy results showing changes in nutrient distribution following humidification. The proportionality of amounts of calcium and magnesium leached and released during decomposition is likely to suggest a similarity of chemical form more than similarity of function or position of the two elements. Management of crop residues for maximising and optimising the timing of release of different nutrients will need to take into account the placement of different plant types and parts, particle sizes distribution and pre-treatment of material to efficiently manage short- and long-term soil fertility to sustain crops, particularly on degraded soils. Significant nutrient release of potassium, sulphur and magnesium from crop residues can be achieved from surface placement, with the release of potassium and sulphur managed by modifying residue particle size through appropriate harvesting, ploughing or sowing implement selection. High nutrient uptake crops and plant parts where they can be economically viable to grow or separated by the harvesting technique are particularly valuable as sources of nutrients and soil organic matter.
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Deenik, Jonathan Leonard. "Correcting soil nutrient deficiencies with organic materials in the atoll soils of the Marshall Islands". Thesis, University of Hawaii at Manoa, 2003. http://hdl.handle.net/10125/597.
Testo completoAbstract (sommario):
The coralline soils of atolls suffer from multiple nutrient deficiencies that severely limit crop growth. This study was conducted to assess the nutrient status of the soils of the inhabited atolls within the Marshall Islands (MI), and to determine what local materials could be used to correct deficiencies limiting crop growth. Surface and subsoils from 25 atolls were collected and analyzed for their chemical properties, and soil test results were evaluated with a missing element pot study.
Soil tests revealed that the MI soils were severely deficient in K (0.12 cmol c kg -1 ) and marginally deficient in Cu (0.13 ug g -1 ). The missing element study showed that the soil was deficient in K, S, N, P, and Cu. An incubation experiment and a series of greenhouse experiments were conducted to evaluate the ability of locally available organic materials to mineralize N and supply adequate nutrients to crops. Vigna marina and fish meal showed the highest N mineralization capacity, and the Gompertz equation provided the best fit. Chinese cabbage plants grew as well in soils amended with chicken manure, Vigna marina , and copra cake as they did in soil treated with chemical fertilizers. Plants grown in soil amended with fish meal did not grow as well due to inadequate K supply. Nitrogen recovery was highest in V. marina treatment at 92% followed by the chemical control (83%), chicken manure (34%), fish-meal (18%), and copra cake (9%). Added coconut leaves immobilized N and resulted in very poor cabbage growth. Comparisons between relative growth rate (RGR) and nutrient relative accumulation rate (RAR) showed that nutrients supplied from the V. marina amendment to the cabbage plant matched plant demand. In a rate experiment in the greenhouse, adding 10.1 g kg -1 of V. marina leaves (dry weight) supplied 350 mg N kg -1 to 5 week-old corn plants representing 38% of the total amount of N added in the amendment. Splitting the application quantity improved corn growth at the highest addition rate. Copra cake showed less promise as a suitable organic amendment. Supplementing copra with chemical N and P, and V. marina leaves with and without Cu and B did not improve crop growth compared with copra alone. The soil exhibited low P adsorption capacity, and corn and lettuce growth responded to high Olsen P soil levels.
The results of the greenhouse experiments showed that V. marina is a potential organic fertilizer material to correct soil nutrient deficiencies for good crop growth in the Marshall Islands.
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Jones, Mary Pletsch. "Evaluating Nutrient Availability in Low Fertility Soils With Resin Capsules and Conventional Soil Tests". BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/3049.
Testo completoAbstract (sommario):
Commonly used soil analysis and resin capsule procedures are used to assess nutrient status in fertile soils, but their validity in semi-arid ecosystems is unknown. Three studies were performed to assess resin capsule effectiveness in semi-arid ecosystems. An incubation study was completed in which loamy sand and sandy clay loam soils were treated with rates of N, P, Fe and Zn. Each soil treatment was implanted with a resin capsule and incubated for 60 or 120 days. Resin capsules reflected NH4-N and P fertilizer at low rates in the loamy sand. NO3-N reflected rates in both soils, but did not reflect Fe or Zn application. Resin capsule NH4-N was a better indicator than KCl-extractable NH4-N, but resin capsule NO3-N was not as effective as water extraction, and resin capsule P was poor compared to NaHCO3-P. A second study was performed in glasshouse conditions using the incubation study soils. Soils were treated with rates of N, P and resin capsules were placed in pots. Pots were seeded with squirreltail grass (Elymus elymoides) and placed in a glasshouse. Resin capsules were removed at 120 days, soil samples taken, grass harvested and yield measured. Yield and total nutrient removal was correlated to resin NH4-N, marginally related to resin or soil NO3-N, and unrelated to resin P. Yield and total nutrient removal was correlated with application rates and resin NH4-N and NaHCO3-extracted P. The third field study, compared two sites with rates of N and P application were established on clay loam and sandy loam soils. Resin capsule and conventional soil tests for NO3-N, NH4-N and P were measured and plant nutrient status examined. Resin capsules were removed and replaced and soil samples taken every 90 days. Resins P was not related to P application or to plant tissue P but NaHCO3-extracted P was, while resin NO3-N, KCl-extracted NO3-N and NH4-N were correlated to N application and plant N. Soil test P was more effective in predicting P status and bioavailability than resin capsules. Resin NH4-N and NO3-N predicted N status and bioavailability, but soil tests were just as effective in semi-arid conditions.
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Walworth, James. "Soil Sampling and Analysis". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2006. http://hdl.handle.net/10150/144813.
Testo completoAbstract (sommario):
5 pp.Soil testing is comprised of four steps: Collection of a representative soil sample, laboratory analyses of the soil sample, interpretation of analytical results, and management recommendations based on interpreted analytical results.
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Walworth, J. L. "Soil Sampling and Analysis". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011. http://hdl.handle.net/10150/239610.
Testo completo
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Donaldson, Jason. "Are forests restricted by nutrient poor soils? : an analysis of soil nutrient stocks and associated vegetation in the fynbos biome, South Africa". Bachelor's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/26584.
Testo completoAbstract (sommario):
The realized woody biomass of the Fynbos Biome in the Western Cape, South Africa falls below the climatic potential to support woody biomass. The lack of substantial tracts of woody forests has long puzzled ecologists, although patchy nutrient distribution and fire disturbance are thought to play a role. The issue has been confounded in the recent past by the invasion of non-indigenous woody plants into formerly low stature fynbos dominated areas. Despite low wood nutrient concentrations, a substantial proportion of nutrients are locked up in the wood of forests due to the large volume of wood. Nevertheless, nutrient stock analysis indicated that plant available nutrients in the poorest global soils (including fynbos soils) are sufficient to support forests (indigenous and alien). I hypothesized that soil nutrient stocks of the Fynbos Biome are sufficient in quantity to support closed canopy indigenous forests with a woody biomass greater than 225 000 kg ha⁻¹ and that alien Pinus spp. and Eucalyptus spp. have lower nutrient stocks than indigenous fynbos species. The study was conducted in the Orange Kloof Forest Reserve and Jonkershoek Nature Reserve within the Western Cape (South Africa). Soil, wood and leaf samples of representative species were collected from indigenous forest, fynbos, E. globulus and P. halepensis and assessed for nutrient contents. Estimates of potential woody biomass on four different soils indicated that indigenous forests would be limited by fynbos soil stocks to below the 225 000 kg ha⁻¹. Pine forest had lower wood nutrient concentrations (mg kg⁻¹, n=6) for N (2466), K (2433), Ca (383), and Fe (34) than indigenous forest species (n=11) N (3427), K (4254), Ca (1636) and Fe (140). The low nutrient stocks in pine wood may allow them to grow tall and be competitive in the shrubby fynbos biome where indigenous forests are limited by expensive wood costs.
16
Klinka, Karel, Pal Varga e Christine Chourmouzis. "Quantitative characterization of field-estimated soil nutrient regimes in the coastal forest". Forest Sciences Department, University of British Columbia, 1999. http://hdl.handle.net/2429/702.
Testo completoAbstract (sommario):
One of the key factors in the site classification of the biogeoclimatic ecosystem classification is soil nutrient regime. Soil nutrient regime (SNR) represents the amount of essential soil nutrients available to plants over a period of several years. SNRs classes are assessed based on field identifiable (qualitative) criteria, not using quantitative measures. There have been several studies that attempted to quantitatively characterize regional soil nutrient gradients in the Coastal Western Hemlock (CWH) zone. In the study summarized here, the soils are influenced by a perhumid cool mesothermal climate.
The objective of the study was to examine relationships between soil chemical properties and field-estimated SNRs.
17
Kramer, Matthew J. Dwyer John P. Ponder Felix. "Fertilizer effects on soil pH, soil nutrients, and nutrient uptake in swamp white and pin oak seedlings on an alkaline Missouri River bottomland". Diss., Columbia, Mo. : University of Missouri--Columbia, 2008. http://hdl.handle.net/10355/5727.
Testo completoAbstract (sommario):
The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on September 25, 2009). Thesis advisors: Dr. John Dwyer, Dr. Felix Ponder, Jr. Includes bibliographical references.
18
Klinka, Karel, Bernhard E. Splechtna e Christine Chourmouzis. "Quantitative characterization of field-estimated soil nutrient regimes in the subalpine coastal forest". Forest Sciences Department, University of British Columbia, 1999. http://hdl.handle.net/2429/759.
Testo completoAbstract (sommario):
Site classification in the biogeoclimatic ecosystem classification system is based on three differentiating properties: climatic regimes (expressed by biogeoclimatic subzones or variants), soil moisture regimes (SMRs), and soil nutrient regimes (SNRs). A SNR represents a segment of a regional soil nutrient gradient, i.e., soils which provide similar levels of plant-available nutrients over a long period. SNRs are identified in the field using a number of easily observable soil morphological properties and indicator
plant species. However, we need to know to what extent soil nutrient properties support these indirect field-estimates. There have been several studies that quantitatively characterize regional soil nutrient gradients in different climatic regions, but no study has yet been done in the subalpine coastal forest (Mountain Hemlock zone). Influenced by a maritime subalpine boreal climate, high-elevation coastal soils differ from low-elevation soils by having a thicker forest floor and a higher organic matter content. In the study summarized here, relationships between soil chemical properties and field-estimated SNRs are examined and soil chemical properties and field-identified SNRs are related to the site index of Pacific silver fir (Abies amabilis (Dougl. ex Loud.) Forbes)
- one of the major timber crop species in the Coastal Western Hemlock and Mountain Hemlock zones.
19
Smith, Craig Matthew. "An analysis of alternative soil, nutrient, and water management strategies". Diss., Kansas State University, 2011. http://hdl.handle.net/2097/10723.
Testo completoAbstract (sommario):
Doctor of PhilosophyDepartment of Agricultural Economics
Jeffery R. Williams
The two topics addressed in this dissertation are both related to surface water quality. Reservoir sedimentation and water quality trading are examined from economic and environmental perspectives. Each topic and the resulting policy implications are relevant to stakeholders at the local, state, and federal levels. Reservoir sedimentation has been recognized as a major environmental, social, and economic issue in much of the Midwestern US. There is an effort to focus public and private funds to achieve the greatest return on the investment from soil erosion and sediment reduction strategies. How can physiographical and economic relationships within the watershed be quantified in such a way to provide insights into the selection of alternative management strategies? This study focuses on answering that question by integrating a physically-based watershed model with an economic analysis of alternative sedimentation reduction strategies for the case of Tuttle Creek Lake located in northeastern Kansas. Several key finding of this study are that both physiographical and economic factors must be considered for cost-effective conservation to occur. Considering these factors and targeting BMP implementation from 8 to 23 times more cost-effective than random implementation. If targeting cannot be done effectively or if “intangible” costs of BMP implementation are too large, dredging is likely to be more cost-effective. While this research compares the cost-effectiveness of various BMP implementation approaches in Kansas with dredging, the benefits associated with each of these strategies is not addressed. While there is substantial evidence that nonpoint sources have lower nutrient reduction costs than point sources, experience with water quality trading (WQT) reveals a common theme: little or no trading activity. These outcomes suggest the presence of obstacles to trading that were not recognized in the design of existing programs. To examine the ways that various market imperfections may impact the performance of a WQT market, an agent-based model is constructed, which simulates a hypothetical point-nonpoint market. This study first presents an overview of the concepts and simulation modeling technique used and then analyzes the effects of two prominent market impediments identified in the WQT literature: information levels and trading ratios. The results imply that if market designers feel that only a limited number of trades will be consummated, creating an institution that provides accessible information about buyers’ prices is preferred to providing information about sellers’ prices. Overall, more information is always better, but it becomes less important with higher trading ratios.
20
Manuel, Theodore Llewellyn. "Effect of soil nutrient status on stress tolerance in Proteaceae". Bachelor's thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/25615.
Testo completoAbstract (sommario):
Protea lepidocarpodendron grown on low, medium and high nutrient treatments exhibited the lowest, and similar evapotanspiration rates respectively over a 9 day water stress cycle (experimental period). In stressed and unstressed treatments, stomatal conductance and transpiration rates of plants grown on the low nutrient treatment was generally lower than that of plants grown on the medium and high nutrient treatments where stomatal conductance and transpiration rates were similar. Stressed plants grown on the low, medium and high nutrient treatments exhibited the lowest, intermediate and highest photosynthetic rates respectively. Stessed plants grown on the medium and high nutrient treatments exhibited a dramatic decrease in transpiration rates ands stomatal conductance from day 5 to 7, and a dramatic decrease in photosynthetic rates from day 3 to 7. Stressed plants grown on the low nutrient treatment showed a far less dramatic decrease in transpiration rate, stomatal conductance and photosynthetic rate over the 9 day period. For stressed plants, photosynthetic rates varied between 0.08-5.39 uMOLm⁻²s⁻¹, 1.17-7.48uMOlm⁻²s⁻¹ and 1.15-8.65uMOLm⁻²s⁻¹ for plants grown on low, medium and high nutient treatments respectively. Unstressed plants grown on low. medium and high nutrient treatments exhibited the lowest, highest and intermediate photosynthetic rates respectively. In all stressed treatments, photosynthetic rates showed a steady decline from day 1 to day 7, whereafter a dramatic increase occurred in the medium and high nutrient treatments, and a less dramatic increase in plants grown on the low nutrient treatment. These decreases and increases in photosynthetic rates was not parallelled in the stomatal conductance and transpiration rates of the unstressed plants. For unstressed plants, photosynthetic rates varied between 1.4s-4.4 uMOLm⁻²-s⁻¹, 1.65-6.7 uMOLm⁻²s⁻¹ and 3.42-8.76 uMoLm⁻²s⁻¹ for plants grown on low, medium and high nutrient treatments respectively. Plants grown on low nutrient treatments exhibited the highest LSW (182.3 gm⁻²), highest whole plant mass (WPM) (1.07g), followed by high (LSW=1.76 gm⁻²,WPM=0.83g) and medium (LSW=167.28 gm⁻² ,WPM=0.79g) nutrient treatments. Total plant nitrogen content was inversely related to LSW and WPM on low (3.84 mgNplant⁻¹), high (4.18 mgNplant⁻¹) and medium (5.28 mgNplant⁻¹) treatments. Root : ratio between treatments were similar.
21
Babcock, Esther. "Soil Testing and Plant Analysis Relationships for Irrigated Chile Production". Thesis, The University of Arizona, 2010. http://hdl.handle.net/10150/193428.
Testo completoAbstract (sommario):
In a field study of irrigated chile (Capsicum annum L.) production in southeastern Arizona and southwestern New Mexico from 2008 through 2009, soil and tissue test samples were analyzed for a full spectrum of nutrients at 16 different sites, including nitrogen (N) phosphorus (P), potassium (K), zinc (Zn), iron (Fe), and boron (B), with the objective of evaluating soil and tissue nutrient testing procedures and establishing basic testing guidelines and recommendations with respect to yield potentials. Results for soil and tissue analysis were correlated to yield results. The results provide estimates for baselines which can be tested through subsequent calibration experiments for the development of recommendations for critical soil and tissue test values. These soil test and plant nutrients values will be evaluated in subsequent experiments in an effort to better define fertilizer nutrient inputs in order to gain better nutrient management efficiencies in irrigated chile production systems.
22
Klinka, Karel, Han Y. H. Chen e Christine Chourmouzis. "Quantitative characterization of field-estimated soil nutrient regimes in the subalpine interior forest". Forest Sciences Department, University of British Columbia, 1999. http://hdl.handle.net/2429/716.
Testo completoAbstract (sommario):
Site classification of the biogeoclimatic ecosystem classification system is based on climatic regime (expressed by biogeoclimatic subzone), soil moisture regime (SMR), and soil nutrient regime (SNR). A SNR represents a segment of a regional soil nutrient
gradient, i.e., a population of soils which provide similar levels of plant-available nutrients over a long period. SNR is identified in the field using a number of easily observable soil morphological properties and indicator plant species. However, we do not know the extent to which soil nutrient properties are supported by these indirect field-estimates. There have been several studies that quantitatively characterized regional soil nutrient gradients in different climatic regions (see Sciencia Silvica Number 21 for
subalpine coastal forests), but this has not been done in the subalpine interior forest (Engelmann Spruce - Subalpine Fir (ESSF) zone) where soils are influenced by a continental subalpine boreal climate. In the study summarized here, relationships between
soil chemical properties and field-estimated SNRs are examined and soil chemical properties and field-identified SNRs are related to the site index of subalpine fir (Abies lasiocarpa (Dougl. ex Loud.) Forbes) and Engelmann spruce (Picea engelmannii Parry ex
Engelmann) - two major timber crop species in the ESSF zone.
23
Mestelan, Silvia A. "Impact of long-term no till and plow till on soil properties and soil nutrient cycling". Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1199221756.
Testo completo
24
Kwari, J. D. "Effects of straw burning and drying-rewetting cycles on the fertility of some soils of North-East Nigeria". Thesis, University of Aberdeen, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379809.
Testo completoAbstract (sommario):
The effects of straw burning and drying-rewetting cycles on nutrient availability were studied in an attempt to assess the practical importance of the yearly precropping practice by farmers of burning off excess crop residues and of the seasonal climate of North-East Nigeria. Changes in soil properties resulting from heating three soils up to 700°C and from field burning of straw on three soils were determined. Heating to 250° did not affect soil texture but increased exchangeable NH4+-N, available P, Fe, Mn and phosphate adsorption. A peak of NH4+-N representing decomposed organic N, retained by cation exchange sites was observed after heating at 250°. Soil physical and chemical properties were changed by heating to ≥500^o, resulting in fusion of clay particles into sand-sized particles, decomposition of soil organic matter and alteration of soil minerals with a corresponding increase in non-exchangeable cation status of the soils. The changes observed after field burning of straw were mainly due to deposition of ash; these include a dramatic increase in phosphate adsorption and addition of considerable amounts of inorganic P and exchangeable cations. The availability to maize of the inorganic P returned in ash after field burning or released as a result of laboratory heating of soils was assessed over a 7 day period. The increased P status of the soils after straw burning or heating was not significantly reflected in plant uptake of P but K adsorption was enhanced from the ash. Fertilization of heated and field burnt + overlying ash soil samples resulted in adsorption of P with a corresponding reduction of P concentration in the soil solution and P uptake. The N mineralized after rewetting air-dried clay soils or those containing very low organic matter was insignificant. Investigations also showed that, when dried soils were rewetted, the flush of mineral N was derived mainly from soil organic matter and not from killed microbial cells.
25
Stark, S. (Sari). "Reindeer grazing and soil nutrient cycling in boreal and tundra ecosystems". Doctoral thesis, University of Oulu, 2002. http://urn.fi/urn:isbn:9514266927.
Testo completoAbstract (sommario):
Abstract
In northernmost Fennoscandia, grazing by reindeer
(Rangifer tarandus L.) has a substantial impact on
the vegetation of boreal forests and arctic-alpine tundra heaths, which
are reflected in below-ground processes, such as nutrient mineralization
and soil organic matter decomposition. In the present thesis, the effects
of reindeer grazing on soil nutrient cycling were studied by comparing
grazed situation with an ungrazed control area in ten boreal forests and
six arctic-alpine tundra heaths.
In boreal forests, reindeer grazing reduced microbial respiration in
both the oligotrophic and mesotrophic study areas, indicating a deficiency
of labile substrates for the soil microbes due to reindeer grazing.
Simultaneously, there was heterogeneity in the impact on nitrogen
mineralization rates as at some sites, mineralization was enhanced by
grazing. The fertilization effect of urine and faeces can therefore be
strong enough a factor to outweigh a reduction in quality of soil organic
matter. In the oligotrophic forests, low soil moisture content in the
grazed areas could sometimes limit the mineralization rates even when the
potential for mineralization was enhanced by grazing.
In the tundra ecosystems, there was spatial variation in the impact
of grazing on microbial respiration and nitrogen mineralization. Low
grazing intensity occurring outside the growing season had a retarding
impact on nutrient cycling in both unfertilized, nutrient-poor and
fertilized, nutrient-rich conditions. In contrast, a relatively high
grazing intensity enhanced the mineralization rates in two nutrient-poor
and two nutrient-rich tundra heaths. When three different grazing
intensities were compared in one oceanic, nutrient-rich and one
continental, nutrient-poor tundra heath, the strongest positive effect of
grazing on soil nutrient cycling occurred in the heavily grazed areas. The
data do not support the assumption that soil nutrient availability
regulates whether herbivores enhance or retard nutrient cycling in the
soil. Instead, the net effect of grazing is determined by the balance
between the underlying mechanisms that may work at opposite directions.
The most important of these mechanisms are the grazer-mediated impact on
the decomposability of the dominant vegetation and fertilization by urine
and faeces.
The duration, intensity and seasonal timing of the grazing seem to
be important factors that regulate whether reindeer grazing enhances or
retards soil nutrient cycling in each specific area. Due to the high
spatial and temporal variation in the effects of grazing observed in this
study, it is not possible to generalize the overall impact of grazing.
Further study is required in order to determine the exact conditions under
which grazing enhances or it retards soil nutrient cycling.
26
Wade, Jordon. "Soil Health and Nutrient Dynamics in Agroecosystems of the Midwestern US". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555334900543422.
Testo completo
27
Mwafulirwa, Lumbani. "The potential for root trait selection to enhance soil carbon storage and sustainable nutrient supply". Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=231426.
Testo completoAbstract (sommario):
Plant roots are central to C- and N-cycling in soil. However, (i) plants differ strongly in tissue recalcitrance (e.g. lignin content) affecting their mineralization in soil, and (ii) rhizodeposits also vary strongly in terms of the metabolites that they contain. Therefore, (i) we used 13C labelled ryegrass root and shoot residues as substrates to investigate the impact of tissue recalcitrance on soil processes through controlled incubation of soil, (ii) we assessed variations in root C-deposition between barley genotypes and their respective impacts on soil processes using 13CO2 labelled plants, (iii) using 13C/15N enriched ryegrass root residues as tracer material, we investigated the impacts of barley genotypes on mineralization of recently incorporated plant residues in soil and plant uptake of the residue-derived N, and (iv) we applied a quantitative trait loci analysis approach to identify barley chromosome regions affecting soil microbial biomass and other soil and root related traits. In the first study, addition of root residues resulted in reduced C-mineralization rates, soil microbial activity and soil organic matter (SOM) priming relative to shoot residues. Planted experiments revealed (i) genotype effects on plant-, SOM- and residuederived surface soil CO2-C efflux and showed that incorporation of plant derived-C to the silt-and-clay soil fraction varied between genotypes, indicating relative stabilization of root derived-C as a result of barley genotype, (ii) that plant uptake of residue released N between genotypes was linked to genotype impacts on residue mineralization, and (iii) barley chromosome regions that influence plant-derived microbial biomass C. These results (i) suggest that greater plant tissue recalcitrance can lower soil C-emissions and increase C-storage in soil, and (ii) demonstrate the barley genetic influence on soil microbial communities and C- and N-cycling, which could be useful in crop breeding to improve soil microbial interactions, and thus promote sustainable crop production systems.
28
Shan, Shan. "The controls of nutrient limitation on resource allocation belowground". Miami University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=miami1580078025127756.
Testo completo
29
Schalau, Jeff W. "Laboratories Conducting Soil, Plant, Feed, or Water Testing". College of Agriculture, University of Arizona (Tucson, AZ), 2016. http://hdl.handle.net/10150/625536.
Testo completo
30
Bilal, Ruba Candiga. "Soil Carbon and Nutrient Cycling Across Cover Types in Southern Appalachian Hardwood Forests". Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/85625.
Testo completoAbstract (sommario):
Appalachian mixed hardwood stands along south facing slopes of the Ridge and Valley physiographic province were used to determine fine scale soil respiration (Rs ) and nutrient dynamics among four distinct cover types, white oak (WO, Quercus alba L.), scarlet oak (SO, Quercus coccinea Muech.), chestnut oak (CO, Quercus montana Wild.) and a pine-oak co-dominant cover (PO, Pinus spp. and Quercus spp. (primarily Pinus pungens Lamb. and Q. montana)). Null hypotheses were that: (1) Rs and its relationship to environmental drivers would not differ among the cover types, (2) water and nutrient use efficiencies (WUE and NUE) would not differ among the cover types, and (3) litter decomposition would not differ among the diverse cover types. In 0.02 ha plots, replicated four times, Rs and associated variables (e.g., soil temperature and moisture) were measured. Measurements occurred in three sub-sample locations per plot, from July 2014 - December 2015. In each plot, foliage from two trees of the dominant species were collected to determine WUE using δ¹³C isotope discrimination. Nutrient (N, P and K) content of this fresh foliage was compared with that of litterfall to determine NUE. Litterbags, collected over a one and half year period were used to determine decomposition rate constants for each dominant species. Soil temperature and moisture explained 71% of the variability in Rs. Although only slight, there were statistically significant differences in the Rs models due to cover type. At the same soil temperature, the PO cover type had the highest Rs while the SO, WO cover types had the lowest Rs. WUE, and NUE varied among cover types. SO had significantly greater WUE than the other species, including Table mountain pine, which had the highest NUE. Higher elevation cover types (i.e., PO and CO) ad greater decomposition rate constants. Among the factors driving decomposition, soil C: N ratio had the strongest correlation to decomposition. Correlations between decomposition and productivity variables of total above ground biomass, total stand biomass, and aboveground net primary production also exist. In conclusion, carbon and nutrient cycling varies across the level of cover type within the southern Appalachian hardwood forests. Future efforts to focus on carbon and nutrient dynamics in the context of land use or global change should consider these finer-scale differences.Ph. D.
31
Lindberg, Niklas. "Impact of climate change on soil fauna diversity : effects of experimental drought, irrigation, soil warming and nutrient addition /". Uppsala : Swedish Univ. of Agricultural Sciences, 2001. http://epsilon.slu.se/avh/2001/99-3576673-X.pdf.
Testo completo
32
Simmons, Jason. "Influence of Poultry Litter on Dark Tobacco Growth and Soil Nutrient Availability". TopSCHOLAR®, 2004. http://digitalcommons.wku.edu/theses/516.
Testo completoAbstract (sommario):
Due to the relatively high value of dark tobacco compared with fertilizer costs, nitrogen is recommended at levels as high as 338 kg ha"1. Such rates of inorganic fertilizers increase the osmotic pressure of the soil solution and soil acidity, often causing reduced stands, Mn toxicity, Mo and Ca deficiencies, and reduced yield and quality of the cured leaf (Sims et al., 1984). Poultry litter utilized as a nutrient source is an inexpensive alternative to this dilemma due to its relatively neutral or alkaline composition. However, due the amount of chloride present in poultry litter, the University of Kentucky advises that application be limited to a maximum of 9 Mg ha"1 (Wells, 1996). Environmental concerns such as nitrate contamination of groundwater, P runoff into surface water, and accumulation of heavy metals in the soil are often related to excessive application of poultry litter. Studies were conducted at Western Kentucky University's Agricultural Research and Education Complex in Bowling Green, Kentucky and a farm in Owensboro, Kentucky to evaluate the influence of poultry litter on dark tobacco growth and soil nutrient concentrations. Results from these studies indicate that when applied at recommended rates, poultry litter in most cases can alleviate soil acidification often associated with the use of inorganic fertilizer sources. In general, poultry litter amendments increased soil pH, while inorganic fertilizers had the opposite effect. Data from the Rate Study suggests that rate of inorganic fertilizer and soil pH are negatively correlated. Due to the high nutrient content of poultry litter, its utilization could possibly lead to an accumulation of P2O5 and certain heavy metals, such as Cu and Zn. Data from the Bowling Green Timing Study indicated that poultry litter amendments increased postharvest soil P availability compared to inorganic fertilizer amendments. At the Owensboro location there were no differences in soil P availability among treatments. Results from the Rate Study suggest that soil P availability and poultry litter rate were positively correlated. Data from all studies indicate that in some cases, soil Cu availability was greater in poultry litter treated plots than in plots treated with inorganic fertilizers. With one exception, plots receiving poultry litter were higher in soil Zn availability than inorganic fertilizer plots at the Bowling Green Timing Study. Data from the Rate Study suggests that increasing the poultry litter rate increased soil Zn availability in poultry litter plots receiving a sidedress application. Data from the Owensboro Timing Study indicated that regardless of application timing, cured lamina tissue chloride concentration in poultry litter amended plots were greater than the tobacco industry standard of 1%. Chloride concentrations in the lamina and stem were higher in plots receiving poultry litter than plots treated with inorganic fertilizers. Despite these concentrations there were no noticeable differences in curing and USDA quality rating. Data from the Timing Studies indicated that total yields were equivalent in poultry litter and inorganic fertilizer treated plots, however yields of certain grades did vary. Plots receiving a source of fertilizer had higher total yields than the untreated control. Results from the Rate Study showed that total yields were quite variable, which may be attributed to poor water drainage from the study area. In the Rate Study, a general trend emerged in which increasing the rate of poultry litter in combination with a sidedress application increased trash, lug, and total yield, but decreased tip yield.
33
Kabzems, Richard Darwin. "Quantitative classification of soil nutrient regimes of some mesothermal Douglas-fir ecosystems". Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24691.
Testo completoAbstract (sommario):
Previous attempts to classify nutrient regimes of forest soil have been qualitative evaluations utilizing vegetation and/or physiographic site characteristics, morphological soil properties, and parent material. The major objective of this study was to describe and classify the soil nutrient regimes (SNR) of some Pseudotsuga menziesii ecosystems on southern Vancouver Island, British Columbia. The order of increasing variability for forest floor properties was pH(H₂0) Graduate
34
Holtham, Deborah Anne Lydia. "Enhanced soil structuring beneath white clover and its impact on nutrient transport". Thesis, University of Plymouth, 2006. http://hdl.handle.net/10026.1/2315.
Testo completoAbstract (sommario):
Previous work at IGER has revealed that soil structural differentiation under white clover is phenomenally rapid and enhanced when compared with ryegrass. White clover is one of the most nutritious and widely distributed forage legumes. Its use is advocated in sustainable systems of livestock production because of its ability to acquire atmospheric N through biological fixation in the root nodules. It thus provides an economically viable alternative to the N-demanding conventional system, and a possible solution to reduce the environmental impacts of nitrate leaching from agricultural land. There are, however, potentially negative impacts associated with improving soil aggregation through the use of clover that need further investigation. It appears that legume-based systems are not environmentally benign: similar amounts of N and P are leached from beneath grass-clover swards as those leached from beneath fertilised grass operating at the same level of production. In some circumstances, clover rich swards can give rise to very high levels of nitrate leaching. Thus, this observation of clover induced soil aggregation has important implications for the pollutant transport qualities of soils and for the organic/conventional agriculture debate. Re-packed soil columns of four soil series and 0.5 m intact monoliths of the Crediton series were planted with white clover, perennial ryegrass and a mixture of the two species, and managed according to an organic and conventional farming regime. Visual observations revealed a rapid enhancement in soil structure beneath white clover compared to ryegrass and unplanted soil. A novel technique to determine oxygen diffusion as an indicator of soil porosity, gave a diffusion rate that was nearly nine times greater than that of the grass treatments and fifteen times greater than the unplanted control soil, with intermediate values for the mixed treatment Thus enhanced structural differentiation beneath white clover was supported by greater permeability to air and freer drainage to water. Structural stability tests suggested that white clover improved the ability of the soil to maintain its structure under the action of water, and was estimated to be three times more stable than ryegrass. There was also evidence which implied improved shear strength and resistance to mechanical forces. Differences in soil structure were verified with water retention measurements, which showed a greater proportion of macropores. The void structure was simulated with the 30 Pore-Cor network model, which also suggested a number of larger pores and a saturated hydraulic conductivity which was four times greater than ryegrass. This also highlighted inadequacies in the current standard ISO protocol for water retention. The solute transport studies showed elevated levels of nitrate and phosphate leaching. Concomitant transport of bromide inferred structural differentiation and changes in leaching dynamics. In addition, white clover allowed the passage of greater volumes of water. Most importantly, this was manifested at the soil profile scale and therefore likely to be of consequence in the field. The implications of the research are that enhanced soil structure beneath white clover alters the transport of gases, water, nutrients and other dissolved substances. Further understanding of these soil processes are needed before advocating the use of forage rich legumes in sustainable systems, and for the development of management strategies.
35
Cairney, John W. G. "Basidiomycete linear mycelial structures as nutrient absorbing and translocating organs in soil". Thesis, University of Liverpool, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380064.
Testo completo
36
Asandei, Ancuta. "Global warming : carbon-nutrient interactions and warming effects on soil carbon dynamics". Thesis, University of Exeter, 2014. http://hdl.handle.net/10871/17537.
Testo completoAbstract (sommario):
In order to predict how terrestrial ecosystems will respond to global change, there is growing recognition that we need to better understand linkages between plant and soil processes. Previously the factors and processes with potential to influence the terrestrial carbon (C) cycle have been investigated in isolation from each other. This study investigated the interactions of nutrient availability and warming in controlling the soil carbon dynamics, with regards to the fate of already sequestered carbon in soil, under conditions of increasing atmospheric temperatures. The project objectives were addressed by three independent experiments designed to explain specific components of the carbon-nutrient cycle interactions, and the findings brought together to describe the implications for future soil carbon storage. The main measurements collected throughout this project included soil carbon dioxide (CO2) fluxes, partitioned into autotrophic and heterotrophic components, net ecosystem exchange and respiration fluxes, and background soil moisture and temperature data, backed by gas, soil and biomass analyses. In the two field experiments, these measurements were taken from plots with or without any inorganic nutrient additions or in the presence or absence of legumes providing biological nitrogen addition to the ecosystem. In the laboratory, temperature and nutrient availability were manipulated within the ecosystem. The reduction in decomposition rates, without reduction of productivity as a result of inorganic nutrient additions, indicated the potential for increasing C storage. There was also evidence that nutrient availability controls the strength of the link between plant and soil processes in semi-natural grasslands. The yields, decomposition rates and soil C fluxes recorded in the presence and absence of legumes provided some evidence of N2 fixation, improving ecosystem productivity and soil properties while reducing soil C effluxes, in a managed grassland. In the laboratory, the warming of soils from lysimeters with and without plants, receiving or not receiving fertiliser, supported the findings from field experiments regarding the importance of the soil-plant link in controlling C fluxes. However, C stocks and δ13C analyses showed that over a year’s worth of warming and nutrient manipulations made little difference to the amount of C stored in the soil, indicating that edaphic factors have greater control over the response of C dynamics to increased temperatures.
37
Hollinger, Eric, of Western Sydney Hawkesbury University e Faculty of Environmental Management and Agriculture. "Links between management of a market garden and stormwater losses of sediment, nitrogen and phosphorus". THESIS_FEMA_XXX_Hollinger_E.xml, 1998. http://handle.uws.edu.au:8081/1959.7/306.
Testo completoAbstract (sommario):
Market gardening is commonly characterised by intensive cultivation, high inputs of both organic and inorganic fertilisers, chemical over/misuse, frequent irrigation, and a low degree of soil cover. While market gardening is readily perceived to be detrimental to waterways, there is remarkably little data to quantify the impacts. Soil and nutrient loss in stormwater runoff varies with soil type, climate and production systems. Therefore local data are needed to determine the impact of market gardening on the Hawkesbury-Nepean. This should lead to a better understanding of how land management influences runoff quantity and quality so that practices can be improved. Objectives of this research were to : quantify sediment, N and P loss and assess the implications for waterways; relate sediment, N and P losses to specific land management practices and assess their impacts on profitability; and, reflect on this research in terms of extension and adoption of better land management. An 8.8 ha property with 6.6 ha of market garden was used as a case study in the Hawkesbury-Nepean Catchment. Soil samples were collected at the beginning and end of the study. Sediment core samples were collected from the drainage channel. A rainfall simulator was used to compare runoff volume from green manure and bare fallow beds. The research produced several recommendations for the extension and adoption of improved land management. In order to reduce sediment, N and P losses in stormwater, the primary focus should be on improving soil and nutrient management, in particular matching fertiliser inputs more closely to nutrient requirements. The secondary focus should be on utilising structural measures, in particular farm dams, to prevent pollutants from entering waterways. The outcome should be decreased costs to the farmer and decreased impacts on waterways. The use of N-fixing green manure to decrease the use of poultry manure should be explored.Master of Science (Hons)
38
Campbell, John Mark. "Release of carbon and nitrogen from acid peats as influenced by some tree species". Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/13300.
Testo completo
39
Selin, Steven J. "Soil Heterogeneity Changes During Forest Succession: Test of a Model Using Univariate and Geostatistics". Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/32485.
Testo completoAbstract (sommario):
We sampled forest stands in upland forests of the Southeastern US along a chronosequence of a replicated successional forest sere (1, 6, 10, 25, and 80 years) to elucidate the temporal changes in soil spatial heterogeneity. Samples were collected from loblolly pine plantations representing reorganization through aggradation phases of succession, and from one set of oak-hickory stands to signify the steady-state phase of the model. These trends are characterized and compared to a conceptual model of pattern dynamics. Variability in soil properties (NO3, NH4, pH, Total N, Total C) and forest floor litter at scales relevant to individual plants was quantified using univariate and geostatistical procedures. Global variation (using both coefficient of variation and standard deviation), patch size and proportion of spatially structured variation were examined for individual variables at each successional stage. These patterns were also averaged to produce a generalized model of spatial heterogeneity change during succession. Individual variables often showed differing patterns. However, when patterns from individual variables were averaged, overall patterns emerged. Early in succession global variability was largest and patch sizes were smallest. As succession progressed, trends in the data showed that global variability decreased and patch sizes increased to the middle stage of succession. Both of these trends fit our conceptual model of pattern dynamics. However, the slopes in these trends were not significant at alpha=0.05.Master of Science
40
Murata, Monica Rujeko. "The impact of soil acidity amelioration on groundnut production and sandy soils of Zimbabwe". Diss., University of Pretoria, 1995. http://upetd.up.ac.za/thesis/available/etd-08152003-155125.
Testo completo
41
Lin, Wen. "Nutrient Uptake Estimates for Woody Species as Described by the NST 3.0, SSAND, and PCATS Mechanistic Nutrient Uptake Models". Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/34325.
Testo completoAbstract (sommario):
With the advent of the personal computer, mechanistic nutrient uptake models have become widely used as research and teaching tools in plant and soil science. Three models NST 3.0, SSAND, and PCATS have evolved to represent the current state of the art. There are two major categories of mechanistic models, transient state models with numerical solutions and steady state models. NST 3.0 belongs to the former model type, while SSAND and PCATS belong to the latter. NST 3.0 has been used extensively in crop research but has not been used with woody species. Only a few studies using SSAND and PCATS are available. To better understand the similarities and differences of these three models, it would be useful to compare model predictions with experimental observations using multiple datasets from the literature to represent various situations for woody species. Therefore, the objectives of this study are to: (i) compare the predictions of uptake by the NST 3.0, SSAND, and PCATS models for a suite of nutrients against experimentally measured values, (ii) compare the behavior of the three models using a one dimensional sensitivity analysis; and (iii) compare and contrast the behavior of NST 3.0 and SSAND using a multiple dimensional sensitivity analysis approach. Predictions of nutrient uptake by the three models when run with a common data set were diverse, indicating a need for a reexamination of model structure. The failure of many of the predictions to match observations indicates the need for further studies which produce representative datasets so that the predictive accuracy of each model can be evaluated. Both types of sensitivity analyses suggest that the effect of soil moisture on simulation can be influential when nutrient concentration in the soil solution (CLi) is low. One dimensional sensitivity analysis also revealed that Imax negatively influenced the uptake estimates from the SSAND and PCATS models. Further analysis indicates that this counter intuitive response of Imax is probably related to low soil nutrient supply. The predictions of SSAND under low-nutrient-supply scenarios are generally lower than those of NST 3.0. We suspect that both of these results are artifacts of the steady state models and further studies to improve them, such as incorporating important rhizospheric effects, are needed if they are to be used successfully for the longer growth periods and lower soil nutrient supply situations more typical of woody species.Master of Science
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Formaglio, Greta [Verfasser]. "The effect of reduced management intensity on soil nutrient dynamics in a large-scale oil palm plantation: soil nitrogen cycle, asymbiotic nitrogen fixation and nutrient leaching losses / Greta Formaglio". Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://d-nb.info/121533852X/34.
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Singbo, Arnaud. "The effect of zinc and soil ph on grain yield and nutrient concentrations in spring wheat cultivated on potted soil". Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2845.
Testo completoAbstract (sommario):
Thesis (MTech (Agriculture))--Cape Peninsula University of Technology, 2018.Zinc deficiency on various soil types have been reported in arable soils of sub Saharan Africa (SSA) including South Africa. A pot trial was conducted at the Cape Peninsula University of Technology, Wellington campus to investigate the interaction of different application rates of Zn at various soil pH on the grain yield and quality of spring wheat in a completely randomized factorial design replicated three times. The four soil pH tested were: pHA: 5.1, pHB: 5.6, pHC: 6.1, pHD: 6.6 which correspond to lime application at 0, 0.5, 1 and 1.5 t/ha. Five Zn rates (Zn1: 3.5; Zn2: 4.5; Zn3: 5.5 Zn4: 6.5, and Zn5: 7.5 mg /kg soil which correspond to Zn1: 7; Zn2: 9; Zn3: 11; Zn4: 13 and Zn5: 15 kg /ha) were applied at two (planting and flowering) growth stages. Yield and yield component data collected were analyzed using SAS version 9.2 and means were separated by Duncun’s Multiple Range Test (DMRT). The results showed that grain yield and yield components were significantly affected by lime application pHC (6.1): 1t/ha at planting. Zn application at planting had no significant effect on the grain yield and yield components. However, at flowering, the simultaneous increase of Zn along with increase in lime positively affected grain yield and yield components. Plant analysis showed that at both stages (planting and flowering), Zn application, especially at pH 6.6, significantly increased P, K, Ca, Na, Mg Fe, Cu and B concentrations in wheat grain, but the concentrations of N, Mn, Zn and protein remained unaffected. Zn application had no effect on most nutrients due to the presence of lime. While the absence of lime, Zn4: 6.5mg/kg (corresponding to 13kg/ha) significantly increased the nutrients. In addition, Zn3: 5.5mg/kg (corresponding to 11kg/ha) promoted Zn absorption by grain in all treatments.
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Grans, Catherina. "Tractors and horses in viticulture. Research on soil, grapes, must and labor". Master's thesis, ISA-UL, 2016. http://hdl.handle.net/10400.5/13342.
Testo completoAbstract (sommario):
Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL / Institut National d'Études Agronomiques, MontpellierHorses versus machines? Who would believe nowadays a mere animal can compete with the power of human engineering. This thesis has the objective to examine the effects of modern technology in viticulture in comparison to an old fashioned way of working with draft animals such as horses. Analyses were carried out during nine months and one vintage in two different vineyards with differences in cultivation practices with horses as draft animals on mostly bare soil or tractors with an alternate natural grass cover in the wine region Palatinate, Germany. Soil textures are the same in both comparable sites. The vineyard which was cultivated with horses is referred as vineyard horse and the vineyard which is cultivated mechanically is referred as vineyard tractor. Organic matter shows higher contents in the vineyard horse in topsoil as well as in subsoil. The C/N Ratio shows no big differences. Mineral contents of soil were measured as nitrogen, phosphor, potassium and magnesium with differences in values. The vineyard tractor counts with a higher average number of clusters per vine. Differences in percentage regarding total botrytis are minimal and vineyards show a higher infestation frequency in the vineyard horse but the infestation strength within the grape is lower in this vineyard. The cultivation with horses show higher values as density level, degree in Oechsle, total extract, pH, total acidity, tartaric acid and malic acid. The analyses of nutrients in must show higher contents of macronutrients in the vineyard horse as nitrogen, phosphor, potassium, calcium, sodium and magnesium. Very high differences can be found within the amounts of nitrogen. The micronutrients in must such as iron, zinc, manganese and copper resulted in very similar values. The labor in working with draft animals in vineyards is more than two times higher compared to the vineyard that is mechanized. It is necessary to get a more detailed view including more vintages and more vineyards which can be analyzed in order to come to a more scientifically sound conclusion.
N/A
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Minca, Kristen Kathleen. "Using Soil Nutrient Tests and 1M HNO3 to Predict Total and Bioaccessible Pb in Urban Soils". The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1325176659.
Testo completo
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Sheldrick, William Francis. "The development of a nutrient audit model for estimating time-series soil nutrient balances at the national, regional and global scales". Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394725.
Testo completo
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Hedlund, Anna. "Nutrient management in smallholder peri-urban farming systems : a case study in southern Vietnam /". Uppsala : Dept. of Soil Sciences, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/9212291.pdf.
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Ceruti, Portia Odessyl. "Crushed rock and clay amelioration of a nutrient decifient, sandy soil of Maputaland". Master's thesis, University of Cape Town, 1999. http://hdl.handle.net/11427/9881.
Testo completoAbstract (sommario):
Bibliography: leaves 57-62.Various studies have suggested the possibility that food derived through subsistence agriculture in the Mseleni region of Maputaland contributes to malnutrition within the local community, particularfy within the high proportion of the population which suffers from a severe, disabling form of osteoarthritis. This study was conducted to determine if the application of local crushed rock or black clay to these nutrient deficient, sandy soils would increase available nutrient concentrations and improve the growth of plants in the ameliorated soil.
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Sheppard, Paul A., Pere Cassals e Emilia Gutiérrez. "Relationships Between Ring-Width Variation and Soil Nutrient Availability at the Tree Scale". Tree-Ring Society, 2001. http://hdl.handle.net/10150/262537.
Testo completoAbstract (sommario):
Within the framework of the linear aggregate model of dendrochronology, the potential role of soil nutrient availability in explaining multi-decadal variation in radial growth at the tree level was studied in the central Spanish Pyrenees. Increment cores were collected from 20 mature Pinus uncinata Ram. and analyzed dendrochronologically. One ion-exchange resin capsule was buried within the root zone of each sampled tree for just over eight months. The resins were chemically extracted and measured for NH₄, NO PO₄, Ca, and K. Statistical relationships between indexed tree growth and soil nutrient availability were determined with regression analysis and bivariate plots. The single most important soil nutrient with respect to decadal-scale dendrochronological tree-growth variables in this study was N in the form NO which explained 22% of variation of trend in growth since 1950. The 20 values of NO₃ availability fell into two subgroups, one of trees with relatively higher NO₃ availability and the other with lower NO₃ availability. When the tree-growth data were grouped based on NO₃ availability, the two resultant index chronologies had different low-frequency features since 1950. Trees with low NO₃ availability have been growing as expected based on past growth, but trees with high NO availability have been growing better than expected. Measuring and analyzing soil nutrient availability at the tree level might enhance environmental applications of dendrochronological research. With soils information at this spatial scale, it is possible to distinguish between subgroups of trees within a tree-ring site and thereby construct subchronologies that differ significantly, especially for variation at the decadal scale. Subsite-chronologies may then lead to different and presumably more informative environmental interpretations relative to those based on a full-site chronology.
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Tregoning, Bailey. "Characterization of ion-selective electrodes for an on-field soil nutrient analysis system". Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/123261.
Testo completoAbstract (sommario):
Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2019Cataloged from PDF version of thesis.
Includes bibliographical references (page 48).
There is an established need for more careful application of soil nutrients and fertilizer to maximize crop yield for an ever-growing population. This study focuses on the manufacturing and characterization of ion-selective electrodes (ISEs) to further study if they could be used to reliably measure soil markers like nitrate, phosphate, potassium, and pH for farming applications. Research into a low-cost design for a soil nutrient analysis system to characterize the viability of farming soil has already begun through proof-of-concept prototypes and testing. This study builds upon such early-stage testing. The goal of this investigation was to build an understanding of the accuracy of these ion-selective electrodes in soil samples. To arrive at the end goal of this investigation, we divided this project into three main stages for these nitrate, phosphate, potassium, and pH ISEs.
Stage one focused on characterizing the performance of ISEs cured in environments with two different oxygen levels, in effort to describe the variation in slope and detection limit contributable to curing environment. This study found that ISEs cured in lower oxygen settings (-10 ppm) were more reliable. Stage two focused on characterizing the selectivity of ISEs for the target ion over interfering ions commonly found in soil, in effort to describe the magnitude of error in a soil measurement due to interfering ions with the ranges found in soils. This study found that the nitrate electrodes tested performed with reasonable selectivity for the interfering phosphate, sulfate, and carbonate ions. Stage three focused on benchmarking the accuracy of the ISEs against standard lab techniques for a library of soil samples. The soil concentrations calculated from the potentials measured by the ISEs were reasonable for some of the soil sample ranges, but not all of them.
The results from these three stages of testing imply that the manufacturing process needs to be updated to include conditioning the ISEs in strontium chloride in effort to improve the reliability and stability of the ISEs.
by Bailey Tregoning.
S.B.
S.B. Massachusetts Institute of Technology, Department of Mechanical Engineering