Dissertations / Theses on the topic 'Soil and Water Sciences'
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Ekanayake, Jagath C. "Soil water movement through swelling soils." Lincoln University, 1990. http://hdl.handle.net/10182/1761.
Full textPoon, David. "Re-conceptualizing the soil and water assessment tool to better predict subsurface water flow through macroporous soils." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119707.
Full textLes stratégies d'intervention ciblées sur la prévention de l'eutrophisation des eaux de surface en milieu agricole devraient prendre en compte que relativement plus de phosphore chemine vers les drains souterrains par les macropores du sol qu'en cheminement matriciel. Afin de décrire les phénomènes de transport de phosphore aux drains, le modèle hydrologique SWAT (Soil and Water Assessment Tool) doit être en mesure de distinguer ces processus de transfert. La présente étude avait pour objectif d'évaluer la performance d'un nouvel algorithme séparant les écoulements matriciels et préférentiels, en mettant à profit des jeux de données existantes et suivant une démarche compatible avec l'approche de modélisation inhérente à SWAT. L'algorithme a d'abord profité d'une validation conceptuelle, hors du modèle SWAT, puis d'une évaluation suivant son intégration à une nouvelle version du modèle hydrologique, SWAT-QC2. La validation conceptuelle de l'algorithme a démontré que les flux matriciels épisodiques prédits augmentent avec les précipitations journalières, à la condition que le taux d'infiltration ait atteint un seuil limite, relativement moins élevé en sol argileux. Bien que l'algorithme n'ait pas amélioré la prédiction du débit total d'un petit bassin versant du Sud du Québec (30 km2), il a néanmoins amélioré la performance du modèle SWAT à répartir les écoulements de surface et souterrains. La comparaison des prédictions du modèle hydrologique avec les résultats de séparation des hydrogrammes à l'exutoire du même bassin versant suivant une méthode chimique témoigne d'une performance réaliste de SWAT-QC2 à prédire la répartition des flux souterrains préférentiels et matriciels. A l'instar de la validation conceptuelle de l'algorithme, les flux préférentiels prédits sont relativement plus importants en sol argileux qu'en texture plus grossière. En décrivant la proportion des écoulements souterrains qui emprunte la voie préférentielle, et qui contrôle potentiellement les transferts souterrains de P, l'algorithme d'écoulement en macropores constitue une assise pour le développement ultérieur de SWAT intégrant une description des transferts souterrains de phosphore vers les drains souterrains. Afin d'améliorer la performance de SWAT-QC2 à séparer les flux préférentiels et matriciels, les développements futurs du modèle hydrologique devraient prendre en compte la nature dynamique de la connectivité des macropores, de même que les effets de l'humidité du sol sur l'écoulement préférentiel. Cette démarche appelle cependant à une meilleure caractérisation expérimentale de la variabilité spatio-temporelle des flux préférentiels en sols agricoles.
Subedi-Chalise, Kopila. "Impacts of Crop Residue and Cover Crops on Soil Hydrological Properties, Soil Water Storage and Water Use Efficiency of Soybean Crop." Thesis, South Dakota State University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10265200.
Full textCover crops and crop residue play a multifunctional role in improving soil hydrological properties, soil water storage and water use efficiency (WUE). This study was conducted to better understand the role of crop residue and cover crop on soil properties and soil water dynamics. The study was conducted at the USDA-ARS North Central Agricultural Research Laboratory, located in Brookings, South Dakota. Two residue removal treatments that include low residue removal (LRR) and high residue removal (HRR) were established in 2000 with randomized complete block design under no-till corn (Zea mays L.) and soybean (Glycine max L.) rotation. In 2005, cover crop treatments which include cover crops (CC) and no cover crops (NCC) were integrated into the overall design. Soil samples were collected in 2014, 2015 and 2016. Data from this study showed that LRR treatment resulted in lower bulk density (BD) by 7 and 9% compared to HRR in 2015 and 2016, respectively, for 0-5 cm depth. Similarly, LRR treatment significantly reduced soil penetration resistance (SPR) by 25% in 0-5 cm depth compared with HRR treatment. In addition to this, LRR treatment significantly increased soil organic carbon (SOC) concentrations and total nitrogen (TN) by 22 and 17%, respectively, in 0-5 cm. Similarly, CC treatment resulted in lower BD and SPR by 7% and 23%, respectively, in 0-5 cm depth in 2015 compared with NCC treatment. The LRR significantly increased soil water infiltration by 66 and 22% compared to HRR in 2014 and 2015, respectively. Similarly, the CC treatment significantly increased infiltration by 82 and 22% compared to the NCC in 2014 and 2015, respectively. The significant impact of a crop residue was observed on soil water retention (SWR) in 2014 and 2015 for the 0-5 cm depth. The LRR and CC treatments increased the soil volumetric moisture content (VMC) and soil water storage (SWS) on the surface 0-5 cm depth. However, the trend was not always significant during the growing season. The CC treatment significantly impacted the soybean yield by 14% and WUE by 13% compared with NCC treatment. Some interaction of residue by cover crops was observed on BD, SPR, VMC, and SWS, which showed that the use of cover crops with LRR can be beneficial in improving the soil properties.
Dryden, Garri A. "Optimum gravel size for use as a soil surface cover for the prevention of soil erosion by water." Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/280469.
Full textShahadha, Saadi Sattar. "Measured Soil Hydraulic Properties as RZWQM2 Input to Simulate Soil Water Dynamics and Crop Evapotranspiration." UKnowledge, 2018. https://uknowledge.uky.edu/pss_etds/110.
Full textUndercoffer, Jason. "Monitoring Phosphorus Transport and Soil Test Phosphorus From Two Distinct Drinking Water Treatment Residual Application Methods." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1243532451.
Full textPricope, Narcisa. "Modeling Soil Erosion in the Upper Green River, KY." TopSCHOLAR®, 2006. http://digitalcommons.wku.edu/theses/258.
Full textZelasko, Amanda Jean. "Soil reduction rates under water saturated conditions in relation to soil properties." NCSU, 2007. http://www.lib.ncsu.edu/theses/available/etd-07172007-154810/.
Full textLIU, ZHIJUN. "Effective modeling of agricultural practices within large-scale hydrologic and water quality simulations." MSSTATE, 2006. http://sun.library.msstate.edu/ETD-db/theses/available/etd-11082006-162139/.
Full textBastviken, Paulina. "Soil water solution DOC dynamics during winter in boreal hillslopes." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-229128.
Full textPeng, Sheng. "Characterizing air-water interfacial area in variably saturated sandy porous media." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280732.
Full textKirsch, B. H. "Solute movement in soil under conditions of evaporating water." Thesis, University of Oxford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357424.
Full textShetterly, Benjamin James. "Soil Phosphorus Characterization and Vulnerability to Release in Urban Stormwater Bioretention Facilities." PDXScholar, 2018. https://pdxscholar.library.pdx.edu/open_access_etds/4354.
Full textLebel, Sarah. "Hydrological modelling of an agricultural watershed in India using the soil and water assessment tool." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104731.
Full textLa productivité des cultures dans le bassin versant Padmalaya en Inde est en-deçà de son plein potentiel, dû à une pauvre disponibilité des ressources en eau. Des structures de collection de l'eau pluviale ont été mises en place, ayant comme objectif d'augmenter la disponibilité de l'eau pour la production agricole. Le modèle hydrologique SWAT a été calibré manuellement pour l'aspect hydrologique, en utilisant des données de débit d'eau dans le basin versant de janvier à juillet 2010. Les simulations ont été faites pour la période 1977-2007, dans différentes conditions de gestion des terres, à l'aide de données météorologiques de la ville de Jalgaon. 16 scénarios ont été construits pour évaluer les impacts sur les processus hydrologiques et les rendements agricoles des changements climatiques, des systèmes de collection de l'eau pluviale, des changements d'affectation des terres, ainsi que des améliorations de pratiques de gestion de l'eau, sur une période de 30 ans. Les résultats des simulations démontrent que les structures de collection de l'eau pluviales contribuent de façon significative à la recharge des aquifères. De plus, l'augmentation des précipitations attribuable aux changements climatiques est susceptible d'engendrer une augmentation des rendements agricoles et de la productivité de l'eau pour les cultures. Malgré le fait que les résultats de ces simulations sont limités à ce bassin versant, les leçons apprises ici en termes d'applicabilité des stratégies de collection de l'eau pluviale dans le cadre des changements climatiques pourront être appliquées à de semblables agro-écorégions de l'Inde.
Harlow, Jeanette. "Assessing Spatial and Temporal Patterns of Groundwater Recharge on Catalina Island, California, from Soil Water Balance Modeling." Thesis, California State University, Long Beach, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10743700.
Full textQuantifying groundwater recharge is of crucial importance for sustainable groundwater management. While many recharge quantification techniques have been devised, few provide spatially and temporally distributed estimates for regional-scale water resource assessments. In this study, a GIS-based and USGS-developed recharge quantification tool ? the Soil Water Balance (SWB) model ? was applied to produce fine-tuned recharge constraints and document spatial and temporal dynamics of recharge. SWB has, as of yet, been tested solely in coastal and continental temperate-humid climate zones. This study expands testing of SWB to a Mediterranean climate zone, focusing on Catalina Island, California. Catalina has experienced significant water supply issues due to a prolonged drought. Using available climate, land use/land cover and hydrology data, the SWB model yields annual recharge values for the time period 2008-2014 of 0.05 mm/year to over 82 mm/year. Results of this thesis provide information on spatial and temporal patterns of groundwater recharge on Catalina Island.
Shiffler, Amanda Kathryn. "Pressurized Hot Water and DTPA-Sorbitol, Viable Alternatives for Soil Boron Extraction." BYU ScholarsArchive, 2004. https://scholarsarchive.byu.edu/etd/328.
Full textMahmood-Ul-Hassan, Muhammad. "Water movement through the unsaturated zone." Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244907.
Full textMiranda, Casey R. "Effects of Recycled Water On Landscape Plants." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/354.
Full textRodriguez, Andres F. "Soil Building Processes in Reconstructed Tree Islands in The Everglades, Florida." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/1021.
Full textThurston, Jeanette Ann. "Occurrence of human pathogenic microsporidia in irrigation water and ultraviolet light and chlorine inactivation of enteric adenovirus type 40 and feline calicivirus." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/290101.
Full textNambuthiri, Susmitha Surendran. "Soil water and crop growth processes in a farmer's field." Lexington, Ky. : [University of Kentucky Libraries], 2010. http://hdl.handle.net/10225/1140.
Full textTitle from document title page (viewed on May 12, 2010). Document formatted into pages; contains: xii, 310 p. : ill. (some col.). Includes abstract and vita. Includes bibliographical references (p. 298-309).
Kurth, Emma Morgan Kurth. "Three field studies to examine cropping management effects on: runoff quantity and quality; soil water content and temperature; and selected soil quality indicators." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1511961519903924.
Full textWraith, Jon M. "Soil Temperature Influence on Water Use and Yield Under Variable Irrigation." DigitalCommons@USU, 1989. https://digitalcommons.usu.edu/etd/1996.
Full textGhezzi, Jessique L. "INFLUENCE OF CLAY MINERALOGY ON SOIL DISPERSION BEHAVIOR AND WATER QUALITY." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/289.
Full textVins, Wesley J. "Residential Septic Tank Effluent Treatment by Disturbed Darien Soil." Connect to resource online, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1266610669.
Full textArneth, Almut. "Fluxes of carbon and water in a Pinus radiata plantation and a clear-cut, subject to soil water deficit." Lincoln University, 1998. http://hdl.handle.net/10182/1955.
Full textReynolds, Sallee. "An Investigation of the Utilization of Soil Water and Nitrogen Among Diverse Forage Plant Species and Mixtures." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/832.
Full textSzafruga, Pawel J. "Soil Water Flux Estimates From Streaming Potential and Penta-Needle Heat Pulse Probe Measurements." DigitalCommons@USU, 2014. https://digitalcommons.usu.edu/etd/3091.
Full textWang, Li. "Simulation of soil water movement model (SWaMM) using the Spider Distributed System." CSUSB ScholarWorks, 2003. https://scholarworks.lib.csusb.edu/etd-project/2419.
Full textMaas, Ellen DvL. "The Cascading Effects of Climate Change on Soil Organic Matter." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1492076671912468.
Full textBartsch, Kevin P. "Modeling Soil Loss to Determine Water Erosion Risk at Camp Williams National Guard Base, Utah." DigitalCommons@USU, 1998. https://digitalcommons.usu.edu/etd/3656.
Full textGoble, Peter. "Maximizing the utility of available root zone soil moisture data for drought monitoring purposes in the Upper Colorado River Basin and western High Plains, and assessing the interregional importance of root zone soil moisture on warm season water." Thesis, Colorado State University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10139009.
Full textRoot Zone Soil Moisture (RZSM) data have both drought monitoring and seasonal forecasting applications. It is the lifeblood of vegetation, an integral component of the hydrologic system, a determining factor in irrigation requirements, and works to govern the means by which energy imbalances are settled between land and atmosphere. The National Integrated Drought Information System (NIDIS) has worked in conjunction with the Colorado Climate Center to improve regional drought early warning through enhanced monitoring and understanding of RZSM. The chief goals of this research have been as follows: 1. Examine regional drought monitoring in the Upper Colorado River Basin and eastern Colorado with specific inquiry as to soil moisture’s role in the process. 2. Develop operational products that can be used to improve the weekly drought monitoring process in the Upper Colorado River Basin and eastern Colorado with an emphasis on utilization of soil moisture data. 3. Review in-situ soil moisture data from high elevation Snow Telemetry measurement sites in Colorado in order to understand the descriptive climatology of soil moisture over the Colorado Rockies. 4. Compare output from soil sensors installed by the Snow Telemetry and Colorado Agricultural Meteorological Network using current calibration methods in order to better understand application of direct comparison between output from the two different sensor types. Engineer a soil moisture core measurement protocol that is reliable within ten percent of the true volumetric water content value. This protocol, if successful on a local plot, will be expanded to alpha testers around the United States and used by the USDA for drought monitoring as well as NASA for ground validation of the Soil Moisture Active Passive (SMAP) Satellite. 5. Expose the seasonality and spatial variability of positive feedbacks that occur between RZSM and the atmosphere across the Upper Colorado River Basin and western High Plains using reanalysis data from the North American Land Data Assimilation System Phase-2 (NLDAS).
Regional drought monitoring was found to involve assimilation of data from a bevy of sources. The decision-making process includes assessment of precipitation, soil moisture, snowpack, vegetative health, streamflow, reservoir levels, reference evapotranspiration, surface air temperature, and ground reports from the regional agricultural sector. Drought monitoring was expanded upon in this research through the development of several products intended for future Colorado Climate Center use. In-situ soil moisture timeseries are now being created from select SNOTEL and SCAN measurement sites. Reservoir monitoring graphics are being produced to accompany spatial analyses downloaded from the bureau of reclamation. More soil moisture data is being used, and now come from an ensemble of models rather than just the VIC model.
While only ten years of data were collected in analyzing the descriptive soil moisture climatology of the Colorado Rockies, these data were telling in terms of the expected seasonal cycle of soil moisture at high elevations. SNOTEL measurements reveal that soil moisture levels peak prior to snowmelt, large decreases in soil moisture are expected in June and early July, a slight recovery is anticipated in association with the North American Monsoon, and the sign of near-surface water balance flips back to positive in the first two weeks of September before soils freeze. Seasonal variance and distribution of volumetric water content varies in ways that are useful to understand from a drought monitoring standpoint. The data show that measurements are affected when soil freezes.
Comparing output from soil sensor relays using sensor types and calibration methods consistent with current SNOTEL and CoAgMet specifications revealed large differences in output regardless of being subject to the same meteorologic conditions.
Soil moisture measurement protocol development proved to be a trial and error process. The data collected at Christman Field was not sufficient proof that soil coring results did come within ten percent of ground truth perhaps due to microscale variations in infiltration. It was possible to develop a protocol of an acceptable standard that could be followed by citizen scientist for an estimated cost of $50.
Results from statistical modeling of post-processed NLDAS data from the last 30 years point primarily to a time frame between May and July in which soil moisture anomalies become significantly correlated with seasonal temperature and precipitation anomalies. This time of year is partially characterized by a climatologic maximization of downwelling solar radiation and a northward recession of the polar jet, but also precedes the anticipated arrival of the North American Monsoon. (Abstract shortened by ProQuest.)
Berg, Karin. "Simulations of groundwater levels and soil water content : Development of a conceptual hydrological model with a continous soil profile." Thesis, Linköping University, Department of Thematic Studies, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1910.
Full textTransport of chemical substances through a catchment depend to a large extent on the water content of the soil through which they are transported. When the groundwater level rise and fall, redox conditions change in the soil and the transport of substances is affected.
The aim of this study is to develop a hydrological model which is able to simulate soil water content at different depths and groundwater level in a soil profile. A new type of conceptual model is developed, which uses a continous represenation of the soil and soil water from the soil surface down to the bedrock. The model is intended to be applied on small catchments at a later stage.
The results show that the simulation of groundwater levels was greatly improved compared to previous results. Simulation of soil water content at selected depths is not yet satisfactory. The runoff simulation was accurate at one of the sites but did not work as well at the other. At one of the sites it was also possible to combine good simulations of runoff and groundwater levels but at the other it was only possible to obtain acceptable simulations of either runoff or groundwater.
It is suggested that model performance could be improved by letting the porosity decrease and the soil water content increase non-linearly with depth. Calculations of evaporation from soil and runoff also need to be modified.
Malizia, John Paul. "Effect of Water Content and Density on the Strength and Deformation Behavior of Clay Soils." Kent State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=kent1460407680.
Full textLaBrie, Holli, and Holli LaBrie. "The Potential Impacts of the Nogales International Wastewater Treatment Plant on the Santa Cruz River." Thesis, The University of Arizona, 2016. http://hdl.handle.net/10150/621145.
Full textFernelius, Kaitlynn Jane. "Post-fire Interactions Between Soil Water Repellency, Islands of Fertility, and Bromus tectorum Invasibility." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3850.
Full textClough, Tim J. "Fate of urine nitrogen applied to peat and mineral soils from grazed pastures." Lincoln University, 1994. http://hdl.handle.net/10182/1030.
Full textSvedin, Jeffrey David. "Characterizing the Spatial Variation of Crop Water Productivity for Variable-Rate Irrigation Management." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/6878.
Full textSöderholm, Simon, and Rebecka Karlsson. "Transport of organic chlorine through soil : A study of organic chlorine in soil water from a catchment in northern Sweden." Thesis, Linköping University, Linköping University, Linköping University, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15226.
Full textChlorine is an element commonly found in the environment of our planet, in the atmosphere, the earth crust and the oceans. Chlorine occurs in two forms, inorganic chloride (Clin) and organically bound chlorine (Clorg), also called organochlorine. For a long time, the organic halogens (among them the organic chlorine) had been considered as produced only by human activities. However, the research of the recent decades suggests a considerably amount of naturally produced organic chlorine in soil and water. Through the research, a hypothesis have emerged, suggesting that there occur a formation of organic chlorine in the top soil layer where chloride is consuming, while the organic chlorine is degrading on deeper soil levels, causing a release of chloride. The study in this thesis attempts to explore the transportation of organic chlorine through soil. 49 soil water samples were collected at three transects, S04, S12 and S22, nearby a stream in northern Sweden and analysed for Clorg, using an AOX-analyser. The results suggest a decrease in concentrations of Clorg by soil depth for transects S04 and S12. The study also indicates that concentrations of Clorg are decreasing with increasing distance from the stream, where the highest mean concentration was found in the organic matter-rich riparian transect S04. Further conclusions are that the spring flood and changes in groundwater level may influence the concentrations of Clorg.
Ämnet klor är vanligt förekommande på vår planet och finns både i atmosfären, jordskorpan och världens oceaner. Klor uppträder i två olika former: oorganisk klorid (Clin) och organiskt bundet klor (Clorg). De organiska halogenerna (bland vilka organiskt klor ingår) har under lång tid ansetts härstamma från enbart antropogena källor. De senaste decenniernas forskning har dock tytt på en naturlig produktion av organiskt klor i mark och vatten. Genom denna forskning har en hypotes tagit form som föreslår en bildning av organiskt klor i de övre marklagren, där klorid binds, medan det i djupare marklager sker en nedbrytning av det organiska kloret vilket medför ett frigörande av klorid. Denna studie syftar till att studera transporten av organiskt klor genom mark. 49 stycken markvattenprover insamlades vid tre provpunkter (S04, S12 och S22) på ett avrinningsområde i norra Sverige och analyserades med hjälp av ett AOX-instrument. Resultaten tyder på en minskning av Clorg med ökande markdjup för provpunkterna S04 och S12. Studien visar även en minskning i koncentration av organiskt klor med ökande avstånd till vattendraget, där den högsta medelkoncentrationen återfanns i provpunkten S04 som ligger nära bäcken och är rik på organiskt material. Vidare slutsater är att vattenflödena under vårflod samt variasionen i grundvattennivå har en påverkan på koncentrationerna av Clorg.
Holleran, Molly E. "Quantifying catchment scale soil variability in Marshall Gulch, Santa Catalina Mountains Critical Zone Observatory." Thesis, The University of Arizona, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1538334.
Full textThe quantification and prediction of soil properties is fundamental to further understanding the Critical Zone (CZ). In this study we aim to quantify and predict soil properties within a forested catchment, Marshall Gulch, AZ. Input layers of soil depth (modeled), slope, Saga wetness index, remotely sensed normalized difference vegetation index (NDVI) and national agriculture imagery program (NAIP) bands 3/2 were determined to account for 95% of landscape variance and used as model predictors. Target variables including soil depth (cm), carbon (kg/m2), clay (%), Na flux (kg/m 2), pH, and strain are predicted using multivariate linear step-wise regression models. Our results show strong correlations of soil properties with the drainage systems in the MG catchment. We observe deeper soils, higher clay content, higher carbon content, and more Na loss within the drainages of the catchment in contrast to the adjacent slopes and ridgelines.
Hart, Timothy David. "Diffusion of ions and water through microbial polysaccharides in the rhizosphere." Thesis, University of Surrey, 1997. http://epubs.surrey.ac.uk/842747/.
Full textSanger, Luke. "Acidic deposition effects on upland organic soils and their drainage water." Thesis, University of Aberdeen, 1993. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU058910.
Full textCulumber, Catherine Mae. "Soil Nutrient Cycling and Water Use in Response to Orchard Floor Management in Stone-Fruit Orchards in the Intermountain West." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/5030.
Full textHedley, Carolyn B. "The development of proximal sensing methods for soil mapping and monitoring, and their application to precision irrigation : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Soil Science at Massey University, Palmerston North, New Zealand." Massey University, 2009. http://hdl.handle.net/10179/1217.
Full textTurmel, Marie-Soleil. "Soil properties and the response of rice production to water regime and fertilizer source in low fertility soils of the Republic of Panama." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103713.
Full textLe Système de Riziculture Intensive (SRI) est un système de production du riz qui préserve les ressources naturelles en utilisant l'irrigation intermittente et la fertilisation organique. SRI apparait comme une alternative aux systèmes de production de riz conventionnels qui utilisent l'irrigation continue et seulement des engrais minéraux; cependant les améliorations de rendement avec le SRI ont été très variables. L'objectif de cette recherche a été de déterminer si les améliorations de rendement dépendent des propriétés du sol avec SRI et quels sont les mécanismes chimiques et biologiques sous-jacents. Une méta-analyse de 72 tests SRI vs systèmes traditionnels dans 16 pays a révélé une réponse significative du rendement au SRI sur sols à faible fertilité (P<0.0001) mais pas de différence sur des sols à moyenne et forte fertilité. Ces résultats ont été validés par une étude en serre. Des sols bas en P (≤7.1 mg P kg-¹) ont réagis positivement à l'irrigation intermittente et aux engrais organiques en augmentant la biomasse de la plante, l'assimilation P, la disponibilité du P du sol, les concentrations microbiennes de P, comparativement aux sols avec irrigation continue et modifiés avec des engrais minéraux NPK seulement. Une étude de terrain investiguant les interactions des types d'alimentation en eau et des types d'engrais a démontré que dans les conditions de limitation de P, les rendements étaient plus importants avec NPK + fumier de vache (compost) qu'avec l'engrais NPK seul sur sols irrigués par intermittence (6.6 t ha-¹ vs 4.9 t ha-¹) et sur sols irrigués en continue (6.8 t ha-¹ vs 6.2 t ha-¹). La concentration P a été augmentée de façon significative par le compost et corrélée au rendement (P=0.007). Selon l'analyse du Système Intégré de Diagnostic et Recommandation (DRIS), lorsque l'N était la substance nutritive la plus limitée, les rendements étaient meilleurs sur des sols à irrigation continue (5.2 t ha-¹) que sur sols à irrigation intermittente (2.7 t ha-¹) en utilisant l'engrais NPK seulement, mais les rendements n'étaient pas différents quand le compost était utilisé. Le compost avait un effet positif sur l'équilibre des substances nutritives de la récolte selon l'analyse de DRIS (P=0.0007). Des essais du SRI dans les fermes à différents endroits du Panama ont montré une augmentation moyenne du rendement de 47% et ont utilisé 86% de moins d'eau. SRI est recommandé en tant que système de production du riz pour préserver l'eau et pour augmenter les rendements de production du riz dans les conditions de limitation du P. La fertilisation organique est recommandée pour améliorer l'équilibre des substances nutritives de la récolte et du rendement dans les conditions de sols irrigués par intermittence.
Shrestha, Paliza. "Water Quality Performance And Greenhouse Gas Flux Dynamics From Compost-Amended Bioretention Systems & Potential Trade-Offs Between Phytoremediation And Water Quality Stemming From Compost Amendments." ScholarWorks @ UVM, 2018. https://scholarworks.uvm.edu/graddis/851.
Full textTvergyak, Jennifer Louise. "Organic By-Product Materials as Soil Amendments." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1339463187.
Full textShrestha, Pratap Kumar. "Incorporating local knowledge in participatory development of soil and water management interventions in the middle hills of Nepal." Thesis, Bangor University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288134.
Full textComte, Irina. "Landscape-scale assessment of soil properties, water quality and related nutrient fluxes under oil palm cultivation: a case study in Sumatra, Indonesia." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=117091.
Full textLa rapide expansion de la culture du palmier à huile en Asie du Sud-Est soulève maintes interrogations sur ses impacts environnementaux. Les planteurs doivent désormais assurer de hauts rendements tout en minimisant leurs impacts. Les impacts environnementaux associés à la déforestation lors de la phase initiale d'établissement d'une plantation sont déjà bien documentés. En revanche, les impacts d'une plantation mature sur la qualité de l'eau a été très peu étudiée. Le palmier à huile est généralement cultivée sur des sols tropicaux peu fertiles d'où la nécessité de forts apports de fertilisants, apports susceptibles de menacer les écosystèmes aquatiques. En Indonésie, les petits planteurs n'utilisent que des fertilisants minéraux tandis que les industriels appliquent, en plus des fertilisants minéraux, des fertilisants organiques issus de leurs usines. Les caractéristiques du sol et la gestion de la fertilisation des palmeraies sont susceptibles d'influer sur la fertilité du sol et sur les transferts de nutriments vers les rivières. Etant donné que les plantations s'étendent généralement sur plusieurs milliers d'hectares, l'effet de la gestion de la fertilisation sur la réponse du sol et les transferts de nutriments vers les rivières nécessite des études à l'échelle du paysage. Celles-ci doivent tenir compte tant de la variabilité du sol au sein de la plantation que de la variabilité des séquences de fertilisation pluriannuelles. Le premier objectif de cette étude est (i) de réaliser une revue de littérature sur les pratiques agricoles utilisées dans les palmeraies ainsi que sur les processus hydrologiques impliqués dans les transferts de nutriments vers les rivières, (ii) d'évaluer l'effet de séquences pluriannuelles de fertilisation minérale et organique sur la réponse du sol, tenant compte de la variabilité des sols, (iii) de caractériser et quantifier les processus hydrologiques dominants impliqués dans le transfert de nutriments, (iv) et enfin d'évaluer l'effet de la gestion de la fertilisation et des caractéristiques du sol sur la qualité des eaux souterraines et sur les flux de nutriments vers les rivières. La zone d'étude est située dans le centre de Sumatra, en Indonésie. Le climat y est tropical humide et les sols peu fertiles (Ferralsols). Il s'agit d'un paysage de 100 km² incluant une plantation villageoise de 1500 ha et une plantation industrielle de 4 000 ha, pratiquant une gestion raisonnée de la fertilisation. Cette étude a montré une amélioration significative des propriétés chimiques des sols suite à des applications continues de fertilisants organiques, avec une amélioration encore plus sensible sur les sols sablo-limoneux que sur les sols limoneux. Une gestion spatiale de la fertilisation à l'échelle de la plantation devrait compléter la gestion à la parcelle pour une meilleure stratégie d'application des fertilisants adaptée à la variabilité des sols au sein de la plantation. Le suivi multi-site sur un an de la qualité des eaux de surface dans le paysage a montré des niveaux de concentrations de nutriments en deçà des limites maximales recommandées par les standards indonésiens. Dans cette étude de cas, la culture d'une palmeraie mature ne semble pas avoir contribué à l'eutrophisation des cours d'eaux. Les raisons en seraient la dilution du système par la forte pluviosité locale, et la pratique d'une fertilisation raisonnée. L'évaluation des flux de nutriments a montré que les sols sablo-limoneux étaient plus sensibles que les sols limoneux aux pertes de nutriments et que la fertilisation organique pouvait réduire significativement ces pertes. Le renouvellement rapide des eaux souterraines induit une grande réactivité du système aux intrants qui peuvent être rapidement drainés vers les cours d'eau. Des apports massifs de nutriments (fertilisation non raisonnée) ou des pesticides liés à la matière organique dissoute pourraient donc entraîner un risque de pollution en aval de l'agrosystème.
Kusumo, Bambang Hari. "Development of field techniques to predict soil carbon, soil nitrogen and root density from soil spectral reflectance : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Soil Science at Massey University, Palmerston North, New Zealand." Massey University, 2009. http://hdl.handle.net/10179/1015.
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