Дисертації з теми "Soil nitrogen status"
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Au, William R. "Relationships between microbial physiological status and nitrogen availability in forest soils." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21506.
Повний текст джерелаColocho, Hurtarte Luis Carlos. "Plant Nitrogen status driving soil organic matter mineralization in the rhizosphere." Universidade Federal de Viçosa, 2016. http://www.locus.ufv.br/handle/123456789/10440.
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Os fatores que regulam a dinâmica do Carbono (C) e Nitrogênio (N) do solo na rizosfera são ainda pouco compreendidos. A mineralização de C na rizosfera pode ser fortemente influenciada pelo estado nutricional da planta, a concentração de CO2 na atmosfera e a temperatura do ambiente, entre outros. Em este estudo, avaliamos o status nutricional de N em plantas de Eucalyptus spp. e sua influência na dinâmica do C e do N n a rizosfera. Realizamos um experimento usando um rhizobox dividido em dois compartimentos. No compartimento de cima plantas foram cultivadas e areia lavada e supridas com uma solução nutritiva contendo todos o nutrientes e a mesma solução porém sem N . No compartimento inferior o contato das raízes com o solo foi limitado usando uma membrana de nylon com abertura de 5 μm. Observamos uma maior razão raiz:parte aérea e maiores concentrações de CO2 no solo das plantas com deficiência de N. As raízes das plantas deficientes em N, apresentaram maiores concentrações em relação as plantas não deficientes em N, de citrato e tallose, e menores concentrações de sucrose e aminoácidos. A análise de C e N da fração de matéria orgânica ligada aos minerais , junto com os dados obtidos pela termoquimolise indicam um aumento na mineralização de C e uma modificação na dinâmica do N. Devido a impossibilidade de contato físico direto com o solo, pela presença da membrana de nylon, a única forma de modificar o solo seria então pela exsudação de compostos pelas raízes. O contrastante conteúdo de aminoácidos e açúcares na raiz, junto com os dados do extrato da solução do solo e de mineralização de C, indica que a composição destes exsudatos diferiu em razão da deficiência de N. Enquanto as plantas deficientes em N exsudaram mais ácidos orgânicos, as plantas com ótimo status nutricional foram capazes de exsudar compostos energeticamente ricos. Os dados de δ13C da matéria orgânica ligada aos minerais indica que as plantas deficientes em N afetaram um maior volume de solo que as plantas supridas de N. Tudo isto mostra que, diferentes mecanismos de efeito priming foram dominantes, dependendo do status nutricional da planta. Em plantas deficiente de N, a mineralização de C no solo foi dominada pelo mecanismo chamado de “mineração de N”, enquanto no solo das plantas supridas de N o mecanismo dominante foi a “estequiometria microbiana”. Este trabalho demostra pela primeira vez, ao nosso saber, a atuação de diferentes mecanismos de efeito priming n a mesma planta, sobre diferente status de N . Assim ressaltando, a importância do manejo de nutrientes na dinâmica do C da rizosfera.
The factors that regulate the dynamics of soil Carbon (C) and Nitrogen (N) in the rhizosphere are still poorl y understood. The soil C mineralization in the rhizosphere ca n be heavil y influenced by plant’s nutritional status, atmospheric CO2 concentration and temperature, among others. In this study, we assess the influence of Eucalyptus spp. N status on the C and N dynamics in the rhizosphere. We performed an experiment us ing two compartment rhizobox. In the upper compartment, plants were cultivated in washed sand and supplied with a solution containing all nutrients or all nutrients but N. The lower compartment limited the contact of the roots with the soil using a 5 μm mesh nylon membrane. We observed a higher root-shoot ratio for the N deficient plants and an increase in its soil CO2 concentration. The roots of the –N planted treatment had higher concentrations of citrate and tallose and lower concentration of sucrose and aminoacids, when compared to the +N planted treatment. The C and N anal ysis of the mineral associated organic matter fraction, together with the thermochemol ysis data showed an increase in C mineralization in both planted treatments and changes in N dynamics. As the roots had no physical contact with the soil due to the nylon membrane, the changes in the soil must have been consequence of root exudation. The contrasting sugar and aminoacid root content, together with the citrate concentration in soil solut ion extract and the C mineralization data, indicate that exudate composition changed due to the plants N status. The data indicates that the plants in the –N treatment exudated more organic acids than the plants of the +N treatment. Still the exudate comp osition of the plants with the +N treatment may had a higher energetic content and thus affected differentl y the soil microbial communities. The δ13C data indicate that the N deficient plants affected a higher volume of soil than the plants of the +N treatment. All this together shows different priming mechanisms were dominant due to the plants N status. As the plants were N deficient, the mineralization of soil C was driven by the “N-mining” mechanism while in the soil of the +N planted treatment the dominant mechanism was “microbial stoichiometry”. This work demonstrates, to our knowledge, by the first time using the same plants, different priming mechanisms due to the plants N status. Thus highlighting, the importance of plants nutrient management in the rhizosphere C dynamics.
Guo, Jingqi. "THE INFLUENCE OF TALL FESCUE CULTIVAR AND ENDOPHYTE STATUS ON ROOT EXUDATE CHEMISTRY AND RHIZOSPHERE PROCESSES." UKnowledge, 2014. http://uknowledge.uky.edu/pss_etds/50.
Повний текст джерелаNeary, Erika L., Daniel G. Neary, Steven T. Overby, and Sally M. Haase. "Prescribed Fire Impacts on Soil Carbon and Nitrogen." Arizona-Nevada Academy of Science, 2002. http://hdl.handle.net/10150/296593.
Повний текст джерелаAu, William R. "Relationships between microbial physiological status and nitrogen availability in forest soils." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ50713.pdf.
Повний текст джерелаMasilionytė, Laura. "Skirtingo našumo dirvožemių pokyčiai ekologinėje ir tausojamojoje žemdirbystės sistemose." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20111207_081456-68509.
Повний текст джерела1. In the cropping systems alternative to the intensive cropping system, set up on a gleyic Cambisol with a different humus status, perennial grasses and biomass of catch crops are a significant reserve of biogenic elements for the productivity of crop rotation plants. 2. In the organic and sustainable cropping systems, farmyard manure and biogenic elements incorporated with it have a greater positive effect on the NPK balance and changes in available phosphorus and potassium in the soil compared with green manure. 3. Catch crops are important from the environmental viewpoint, since by accumulating nitrogen in their biomass they reduce Nmin. concentration in the soil and become a reserve of nutrients for succeeding plants. 4. In the soil with a different humus status, alternative cropping systems have a diverse effect on humus stability and changes in its quality. 5. In the sustainable and organic cropping systems, catch crops and their biomass play an important role for soil physical parameters, agrophytocenoses dominants and total energy.
Botha, Elizabeth Johanna. "Estimating nitrogen status of crops using non-destructive remote sensing techniques." Thesis, University of Limpopo, 2001. http://hdl.handle.net/10386/2562.
Повний текст джерелаBrown, Susann Melissa. "Nitrogen mineralization in boreal forest stands of northwestern Quebec." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0022/MQ29664.pdf.
Повний текст джерелаTacilla, Villanueva Antonio. "Impacts of Fertilization on Soil Properties in Loblolly Pine Plantations in the Southeastern United States." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/54020.
Повний текст джерелаMaster of Science
Selhorst, Adam Louis. "Carbon Sequestration By Home Lawn Turfgrass Development and Maintenance in Diverse Climatic Regions of the United States." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306499049.
Повний текст джерелаMontano, Natalia Margoth. "NITROGEN CYCLING IN HEADWATER WATERSHEDS AND IN MANAGED STANDS OF AUTUMN-OLIVE (ELAEAGNUS UMBELLATA THUNB.) IN SOUTHERN ILLINOIS." OpenSIUC, 2014. https://opensiuc.lib.siu.edu/theses/1393.
Повний текст джерелаNoronha, Sannervik Angela. "Modelling productivity of willow stands in Sweden : evaluation of concepts for radiation use efficiency and soil water and nitrogen availability /." Uppsala : Dept. of Short Rotation Forestry, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/s286-ab.html.
Повний текст джерелаAleshire, Emily Browning. "Forage Systems for the Southeastern United States: Crabgrass and Crabgrass-Lespedeza Mixtures." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/34206.
Повний текст джерелаMaster of Science
Niane, Badiane Aminata. "Le statut organique d'un sol sableux de la zone Centre-Nord du Sénégal." Vandoeuvre-les-Nancy, INPL, 1993. http://docnum.univ-lorraine.fr/public/INPL_T_1993_NIANE_BADIANE_A.pdf.
Повний текст джерелаKlinka, Karel, D. Bradley Collins, Louise E. M. de Montigny, M. C. (Michael Charles) Feller, and Christine Chourmouzis. "Forest floor nutrient properties in single- and mixed-species stands of Western hemlock and Western redcedar." Forest Sciences Department, University of British Columbia, 2001. http://hdl.handle.net/2429/709.
Повний текст джерелаBiggs, Thomas. "Fire Frequency, Nutrient Concentrations and Distributions, and δ13C of Soil Organic Matter and Plants in Southeastern Arizona Grassland". Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/244085.
Повний текст джерелаKanke, Yumiko. "Red edge as a potential index for detecting differences in plant nitrogen status in winter wheat." 2009. http://digital.library.okstate.edu/etd/Kanke_okstate_0664M_10645.pdf.
Повний текст джерелаWesterschulte, Matthias. "Slurry injection to optimize nutrient use efficiency in maize: Soil nitrogen dynamics and plant nutrient status." Doctoral thesis, 2017. https://repositorium.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-2017090116224.
Повний текст джерелаAngelova, Mia. "The nitrogen and sulfur status and isotopes of soils within the vicinity of a coal-fired power station in South Africa." Thesis, 2013. http://hdl.handle.net/10539/12708.
Повний текст джерелаAmplified loads of sulfate and nitrate have caused increased stress on soil systems in many areas of the world, as both are dominant components of acid rain. This is a critical environmental stress due to the damage caused to soil, water quality and ecosystem functioning. Issues concerning the rising emissions of these elements from local industries have begun to attract increasing attention in South Africa, as the rates of deposition in the Mpumalanga Highveld region alone is comparable to those experienced in First World countries. This study sought to investigate the use of natural stable isotopes of sulfur and nitrogen to identify the process transformations that these species undergo in environmental cycles. Total δ34S, δ15N and δ13C isotope signature of soils in the Mpumalanga region were combined with total elemental concentrations to determine the effect of deposition on the soil system. Soil samples from two soil depths (0 – 10 cm and 20 – 40 cm) were taken along a distance gradient from an identified pollution source, the Majuba power station. Long-term air quality data from the study area were also obtained from Eskom’s air quality monitoring stations, as well as sulfur and nitrogen deposition data from selected literature. Elemental concentrations decreased with soil depth as expected, while sites located approximately 25 km downwind of the power station were seen to contain higher concentrations of both soil sulfur and nitrogen. The mean per site soil sulfur concentration across all depths ranged from 0.009 % to 0.048 %, while the mean per site nitrogen concentration across all depths ranged from 0.056 % to 0.346 %. The mean soil carbon concentration in the top-soils ranged from 0.97 % to 7.93 %, and decreased in the sub-soils to 0.490 % to 3.270 %.The mean δ34S value for the top-soils was found to be 8.28 ‰ and increased to 10.78 ‰ in the sub-soils. Soil δ15N also increased with soil depth from 6.55 ‰ to 8.28 ‰. Soil δ13C values were seen to increase from -12.83 ‰ in the top-soils to -11.90 ‰ in the sub-soils. Lighter δ34S values at the surface may be due to anthropogenic deposition. The positive δ34S shift was attributed to a two-source mixing model (atmospheric deposition and bedrock) and isotopic fractionation processes that occur within the soil profile. The δ15N values of the top-soil were higher than what is expected if all nitrogen was derived from atmospheric nitrogen gas fixation. The increase in δ15N with depth suggested that isotope fractionation occurred during nitrogen export due to the faster reaction rate of 14N compared to 15N. The soil δ13C values indicated a typical C4 grassland system. New carbon at the top-soil depths was enriched in 13C due to the slower decay of 13C-depleted lignin; whereas in the sub-soils microbial recycling of carbon dominates and explained the higher 13C content of the older carbon. The conceptual framework presented for this project involves simultaneous processes of deposition and export in the soil system. This was particularly true for sulfur, where sites with lower isotope values had lower soil sulfur concentrations and vice versa. This indicates that high levels of deposition correspond to high net export. The sulfur and nitrogen isotopic signatures could not be used to as a direct means of source identification; however, the effectiveness of isotopes in elucidating transfer of these nutrients in the soil system was illustrated.
(12804776), Stephen Barry Johnson. "Nitrogen fixation by potential ley pasture legumes for Central Queensland." Thesis, 1997. https://figshare.com/articles/thesis/Nitrogen_fixation_by_potential_ley_pasture_legumes_for_Central_Queensland/20010641.
Повний текст джерелаYield decline following continuous cropping cycles in Central Queensland has been attributed to the declining soil nitrogen status. In this study an assessment of the level of nitrogen fixation was made to assist in the selection of potential ley pasture legumes for use in rotational systems to achieve sustainable cropping yields.
Twenty one winter and summer growing legumes were evaluated for nitrogen fixation in glasshouse trials in two seasons. Nitrogen fixation was determined using the hydrogen evolution technique (an instantaneous measure of fixation rate) in an artificial media trial and the 15N natural abundance technique (an integral measure of fixation) in a soil based trial.
Grenier, Michel R. "Effect of annual legumes on the nitrogen status of soils." 1992. http://hdl.handle.net/1993/17984.
Повний текст джерелаLevitt, Elizabeth Anne. "Sources of variation in soil nitrogen availability among postfire lodgepole pine stands in Yellowstone National Park." 2006. http://catalog.hathitrust.org/api/volumes/oclc/71826227.html.
Повний текст джерелаTypescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 27-41).
Huang, Yu-Hsin, and 黃育歆. "The investigation of soil properties, aggregates stability, nitrogen and phosphorus fractions in three forest stands in Xitou." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/67101518826359162794.
Повний текст джерела國立臺灣大學
農業化學研究所
102
Sustainability of forest ecosystems relies on good soil qualities. The diversities of vegetation in forest stands may arise differences in soil properties and affect nutrient cycling. This study aimed to investigate the soil properties, aggregates stability, nitrogen (N) and phosphorus (P) fractions in soils collected from natural broad-leaf stand (Nat-F), Japanese cedar plantation (Cedar-F) and Moso bamboo plantation (Bamb-F) in Xitou, Taiwan. The results showed that soil pH value increased in the order of Nat-F, Cedar-F and Bamb-F; organic matter content was the lowest in Bamb-F soil and no significant difference in electrical conductivity among three forest stands. Concentrations of Mehlich Ⅲ extractable P and potassium (K) decreased in the order of Nat-F, Cedar-F and Bamb-F while manganese (Mn) was the highest in Bamb-F. There was no significant difference in concentrations of Mehlich Ⅲ extractable calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu) and zinc (Zn) among three forest stands. The topsoil (0-10 cm) showed the lowest pH value and the highest electrical conductivities in all studied sites. The organic matter contents and Mehlich Ⅲ extractable P, K, Mg, Fe, Mn and Zn also showed the highest concentrations in 0-10 cm layers. Aggregate stability in Cedar-F and Bamb-F soil profiles was greater than in Nat-F, but there was no differences in aggregate stability in varied depths of the same forest stand. The concentrations of all N fractions studied were the highest in Nat-F and the lowest in Bamb-F soil with the exception of inorganic N and hydrolyzable ammonium N fractions. The concentrations of different fractions of N decreased with increase in depth and were the highest in 0-5 cm soil layer. The Nat-F soil had the highest concentrations of total P, NaHCO3-P and NaOH-P while there was no significant difference in H2O-P, HCl-P and residue-P in three forest stands. In conclusion, there were differences in soils of Nat-F, Cedar-F and bamboo-F in chosen properties, aggregate stability, different fractions of N and P.