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Jamieson, Nicola. "Competition between roots and soil micro-organisms for fertiliser N." Thesis, University of Aberdeen, 1992. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU548165.
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Low fertiliser recoveries are often found for temperate coniferous forests and appear to be associated with the 'locking-up' of residual fertiliser N in stable organic forms. This phenomenon may well be caused by strong microbial immobilisation, out competing uptake by tree roots. This thesis investigates root/microbe competition for fertiliser-derived N (FDN) in microcosms of coniferous forest soil (supporting Sitka spruce seedlings) as well as in re-seeded blanket peat (supporting a mixed grass pasture). Combinations of selective microbial inhibitors, both with and without either 15N-labelled urea or NH4NO3, were applied to microcosms to selectively inhibit target microbial groups which may be competing with roots for FDN and determine the role of microbial immobilisation as a mechanism controlling N flow to seedlings/herbage. The dynamics of FDN novement into microcosm N pools was also studied in microcosms to which 15N-labelled urea was applied alone. At harvest, plant and soil N pools were analysed for 15N and total N (15 N &'43 14N). The impact of biocide and fertiliser N treatments on concentrations of target and non-target soil organisms were also determined. Biocidal (benlate and to a lesser extent streptomycin) inhibition of soil micro-organisms (particularly fungi) increased the uptake of both urea-derived N and NH4O3 N by Sitka spruce seedlings. Increases were associated with reduced percentages of FDA active hyphae and concentrations of FDN immobilised in the microbial biomass of LFH layer and peaty mineral soil. The results suggest that roots were competing with soil microbes for both fertiliser N forms. In conclusion this study has demonstrated the role of microbial biomass, particularly the dominant fungal component as a major competitive sink for fertiliser N and a major factor contributing to the low efficiency of fertiliser N in temperate coniferous forests. The study also has identified selective biocidal manipulation as a powerful technique for characterising competition between roots and microbes for nutrients in soil.
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Harty, Mary. "Evaluation of fertiliser formulations on grassland N use efficiency and nitrous oxide emissions." Thesis, Queen's University Belfast, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.706688.
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Obligations to reduce greenhouse gas emissions (GHG) in agriculture (30% below 1990 levels by 2030) have seen renewed interest in switching from ammonium nitrate (AN) based to urea based fertilisers as a mitigation strategy for GHG emissions. The performance of a comprehensive range of urea based formulations was compared to Calcium AN in a two-year study over three sites across the island of Ireland. The performance criteria were nitrous oxide (N2O) emissions, ammonia (NH3) emissions, grassland yield and N uptake encompassing a range of soils and climatic conditions. The results of the main field experiments showed that all urea formulations reduced N2O emissions relative to CAN in all site-years with larger reductions under the heavier and wetter soil conditions. The inclusion of the urease inhibitor NBPT also reduced NH3 emissions relative to urea and maintained yield and N uptake relative to CAN in all six site-years. In contrast, the nitrification inhibitor dicyandiamide (DCD) showed inconsistent effects on NH3 emissions compared to urea and reduced yield and N uptake relative to CAN in three and four of six site-years respectively. The most climate favourable option was urea incorporating NBPT, however as it is more expensive than urea, a tax on urea or financial incentive to use NBPT will be required to ensure farmers select the stabilised urea incorporating NBPT over urea. In addition, the assessment of N2O emissions from the same fertilisers also contributes to a more detailed accurate national inventory of mineral fertiliser N2O emissions. The tier 1 reporting of emission factors (EF) under the Intergovernmental Panel on Climate Change (IPCC) requirements uses a default EF for N2O from soils of 1% of the N applied, irrespective of its form even though N2O emissions tend to be higher from nitrate-containing fertilisers compared to urea. This research generated tier 2 emission factors for mineral N fertiliser by formulation and soil type.
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Frimpong, Kwame Agyei. "N2O emission and inorganic N release following combined application of crop residues and inorganic N fertiliser into soil." Thesis, University of Aberdeen, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.540326.
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Experiments were conducted at the University of Aberdeen under controlled laboratory conditions to examine the interactive effect of combining crop residues barley (Hordeum vulgare), clover (Trifolium pretense), cowpea (Vigna unguiculata), Leucaena (Leucena leucocephala) and Mucuna (Mucuna pruriens) and inorganic N fertiliser on N2O emission and mineral N dynamics. Emissions of N2O increased following sole application of the residues dependent on their utility or chemical composition. In general emissions were significantly higher from soils amended with low C:N ratio clover, cowpea, Leucena and Mucuna residues compared to the high C:N ratio barley species. N2O emission was further increased following combined application of crop residues and inorganic N fertiliser but the magnitude of emission was influenced by the proportional ratios at which the residue-N and the fertiliser-N were combined, and the C:N ratio, lignin and polyphenols contents of the residues, with the low lignin and low polyphenols cowpea treatment emitting higher N2O over 30 days compared to the high lignin Mucuna and the high polyphenols Leucena treatments. Results from experiments demonstrated that whilst there is the potential for N2O emission to be controlled through varying ratios of residue:fertiliser input, the magnitude and direction of interactions between these N sources varies between different species as a result of their differing qualities. Based on our applications of Leucaena, Mucuna and cowpea residues, the 75:25 residue: fertiliser ratio at 100 mg N kg-1 soil is recommended from this study as offering the best compromise between release of N for crop uptake and management of N2O emission, but this requires further investigation at field scale.
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Burns, Lisa C. "Cycling of fertiliser-derived N in a Sitka spruce ecosystem after 15N-urea application." Thesis, University of Aberdeen, 1992. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU545404.
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Low recovery rates of fertiliser N in tree biomass are frequently reported due to the inefficiency of N fertilisers in afforested ecosystems. At Culloden (North East Scotland), only 13&'37 of 15N-urea fertiliser applied to Sitka spruce could be recovered in the above-ground tree biomass two years after fertilisation. Fertiliser N not taken up by trees was largely 'locked-up' in stable organic forms of N within the LFH layers of the soil profile. 15N-labelled litter was used in both field and microcosm experiments, the release and fate of litter-derived-N (LDN) being traced over the course of two growing seasons. In both experiments, the microbial biomass acted as a major sink for LDN. Measurement of soil microbial biomass was calibrated for Culloden soil samples by determination of a kEN-factor. Tree uptake of LDN, in the field, occurred within one month of labelled-litter application, with the foliage being the largest sink for LDN. Approximately 30&'37 of the N within the labelled-litter layer was taken up by the trees over the course of two growing seasons and was equivalent to 5.4 kg LDN ha-1 y-1. There was considerable mixing of the LFH and peat layers in Sitka spruce microcosm soil profiles. This was probably due to elevated soil animal population densities. After 18 months, approximately 83&'37 of LDN had been redistributed to other N pools in the microcosm. Uptake of LDN by seedlings accounted for 15.7&'37 of LDN after 12 months, the largest sink being the foliage, equivalent to 6.16 kg LDN ha-1 y-1. Again, the microbial biomass was a major sink for LDN. Measurement of availability (NH4+) N in Culloden soil samples incubated at different matric potentials and temperatures, appeared not to reflect N mineralisation rates. There was a strong interaction between temperature and soil matric potential, seedling uptake of N being greatest at 15oC and -16.0 kPa. The rate of turnover of the microbial biomass pool was identified as the key determinant of the rate of processing of LDN in forest soils.
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Ben, Mahmud Merfat, and s3037372@student rmit edu au. "The effect of Burkholderia as biofertiliser on cereal productivity." RMIT University. Applied Sciences, 2009. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20090304.124323.
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Biofertilisers are rhizosphere microorganisms inoculated to reduce the need for N or P fertiliser application and maximise plant growth and nutrition, resulting in greater grain yield and N or P content. This study aimed to evaluate the effectiveness of diazotrophic bacteria isolated from the rhizosphere of wheat in Victoria, Australia. This thesis shows that N2-fixing Burkholderia species have great potential as biofertilisers on wheat productivity. In Chapter 2, strains of bacteria were isolated from wheat-growing soils in main Victoria wheat belt at Horsham and Birchip in North West Victoria. Strains were identified as Burkholderia spp. by their closest matches in the 16S DNA and by morphology and physiology. In Chapter 3, one selected strain from each of Birchip and Horsham were used to inoculate wheat in a pot trial in a glasshouse during winter-spring. Soil was collected on site from wheat fields. Pots were inoculated with these strains to evaluate the effects of Burkholderia inoculum as biofertiliser on the plant growth and yield. Different nitrogen sources (urea 46% N and ammonium sulphate 21% N) were used as fertiliser at one of four levels (0, 50, 100 and 150 kg N/ ha). There was a greater effect in Birchip than in Horsham soil and with ammonium sulphate than with urea due to waterlogying in Horsham soil. In Chapter 4, field-grown wheat was inoculated with the same strains of Burkholderia. Three experiments were carried out in plots at two sites, dryland and irrigated fields at Horsham and a dryland field at Birchip, during the winter wheat season of 2006, to evaluate the effect of Burkholderia species inoculum and different types of nitrogen source at one of four levels of added N (0, 50, 100 and 150 kg N/ha) on wheat growth and yield. The effects of both bacterial inoculation and N fertiliser on growth promotion and grain yield. Since 2006 was a year of drought, dry land crops were unsuccessful. Grain %N as well as total N content in grain per area in the Horsham irrigated field increased with increasing N fertiliser levels up to 100 kg N/ha. In Chapter 5, acetylene reduction (ARA) activity was measured in the pots for both inoculated and uninoculated plants at various growth stages and populations of nitrogen-fixing bacteria associated with the wheat roots and bulk soil were measured in addition to biomass and N content of plants and grain. Molecular tracing using specific primers showed that the inoculum was present only in inoculated treatments. Up to 60% of the increased N content of the grain in inoculated plants was potentially derived from nitrogen fixed by the inoculum in the rhizosphere. It was concluded that the most significant result due to inoculation was the consistent maximal increase of N content in grain in inoculated treatments with ammonium sulphate fertiliser at 100 kg N/ha. Inoculation with Burkholderia consistently increased %N in wheat grain, with the potential benefit of decreasing the production cost and reducing use of chemical fertilisers.
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Liyanage, Anuga. "The impact of using urban derived compost on nitrogen use efficiency, greenhouse gas emissions and productivity from tropical cropping systems." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/134463/2/Anuga%20Liyanage%20Thesis.pdf.
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This thesis is a multiyear study in Sri Lanka to evaluate the impact of using urban derived compost in combination with synthetic N fertiliser on nitrogen use efficiency, greenhouse gas emissions, and productivity from tropical cropping systems. The study demonstrated the high potential for N losses in low CEC tropical soils. However, the high relative cost of OA compared to synthetic N fertilisers requires substantial additional benefits above the value of the nutrients alone to make their use economical.
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Hall, Jennifer M. "Manipulation of N mineralisation/immobilisation dynamics to investigate poor fertiliser recovery in improved grass pasture on ombrotrophic peat." Thesis, University of Aberdeen, 1995. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU068793.
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The spring application of fertiliser N often fails to stimulate grass growth in improved grass pastures on peaty soils. Fertiliser utilisation efficiencies under these conditions have been found to be low, suggesting that available N is not taken up by the plant. Previous work has suggested that in this type of system, the soil microbial biomass may function as a strong sink for fertiliser N and therefore limit plant growth in the Spring. A series of laboratory based experiments utilising reconstituted and intact cores, and homogenised peat, was set up to identify the factors controlling the competition between N uptake by plants and N immobilisation by soil microorganisms following the addition of fertiliser N to peat. Microbial biomass N concentrations were determined in order to quantify the amount of N present in the microbial pool. The use of 15N labelled fertilisers and selective biocides provides a powerful tool with which to characterise the microbial population responsible for the immobilisation of N under these conditions. Improvement of a grass pasture at Sletill Hill has resulted in the formation of a distinct layer comprised of partially decomposed roots, underneath the surface vegetation and it was within this layer, that microbial immobilisation of fertiliser N was found to occur. Approximately 30% of applied N (equivalent to ca 50 kgN ha-1) was found within the microbial biomass in this layer, 30 days after the addition of fertiliser N. Intact cores were removed from Sletill Hill and maintained under controlled abiotic conditions. Water table level and temperature were found to be important in controlling the extent of microbial immobilisation of applied N. Lowering the water table level increased the quantity of N present in plant and microbial N pools, particularly at lower temperatures (8°C). At higher temperatures (20°C), plant uptake of N tended to be less due to a restriction on plant growth caused by 'droughty' soil conditions.
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AlMulla, Abdulaziz Abdulrahman. "Understanding the impacts of changing soil temperature, water irrigation source and fertiliser types on C and N cycling in arid soils." Thesis, Bangor University, 2016. https://research.bangor.ac.uk/portal/en/theses/understanding-the-impacts-of-changing-soil-temperature-water-irrigation-source-and-fertiliser-types-on-c-and-n-cycling-in-arid-soils(8fe82678-4c35-4a67-b38b-74b2c958863c).html.
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Nitrogen (N) is a key regulator of ecosystem development, and the cycling and competition for N resources in ecosystems remains poorly understood. Arid ecosystems are primarily found in North Africa, Middle East and Australia, and cover about one-third of the total global area. Soil organic N (SON) and C cycles are linked; both immobilization and mineralization of N pathways are linked by heterotrophic microorganisms that require C from organic material for production of energy and growth. Therefore, studies into N and C cycles are key to understanding biogeochemical cycles in these areas. Typical agricultural practices in Saudi Arabia (KSA) focus on the production of dates. This study focussed on Al-Hassa oasis - the largest oasis and date supplier in Eastern KSA. The aim of this thesis was to investigate the effect of changing soil temperature, water irrigation sources and fertiliser types on soil C and N cycles within the oasis. To increase our understanding of the effect of aridity on N and C cycle we used 14C techniques to investigate the rate of DON or DOC mineralization by soil microorganisms in response to different temperatures, moisture content and different water types. Initial experiments showed that soil properties decreased dissolved organic nitrogen (DON) and carbon (DOC) mineralization rate whereas, temperature increased mineralization rate in the soil by altering carbon dioxide (CO2) emissions and C partitioning between catabolic and anabolic processes within the microbial biomass. Therefore, we would recommend the farmers and government managers to reduce fertiliser on hot summer that can reduce environmental pollution and cost. Higher C mineralization rates were observed in the soil with the lowest contents of silt, clay, and salinity. The rate of 14CO2 evolution from DON is greater than from DOC compounds with shorter half-life for DON substrates because they are likely to be processed by different metabolic pathways inside the cell. Following on from this, further experiments showed that changing the irrigation water source significantly increased the mineralization of C contained in insoluble plant residues in comparison to that present in the soluble component. The rate of insoluble plant material mineralization was slower than for the soluble component leading to lower rates of 14CO2 loss and a ca. 11-fold longer half-life compared to soluble fractions. Results from the final experiments indicated that applying organic fertilisers would reduce nitrate (NO3-) leaching more than inorganic fertilisers. The information contained in this thesis has improved our fundamental understanding of C and N cycling in arid soil systems. We would recommend the farmers and government managers to reduce inorganic fertiliser and use more organic N fertiliser that can reduce environmental pollution, cost, save more water, and increased yield. Further studies are, however, still needed to investigate the long-term effects of changing soil temperature, water irrigation source and fertiliser types on soil microbial processes in arid soil for developing better water and fertiliser management and reducing N or C gaseous emissions.
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Noellsch, Adam J. "Optimizing crop N use efficiency using polymer-coated urea and other N fertilizer sources across landscapes with claypan soils." Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/5643.
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Thesis (M.S.)--University of Missouri-Columbia, 2008.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 12, 2008) Includes bibliographical references.
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Ditsch, David C. "Fate of ¹⁵N-depleted fertilizer N in a corn-rye cropping sequence: plant uptake and soil distribution." Diss., Virginia Tech, 1991. http://hdl.handle.net/10919/37238.
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Li, Rick Hao Chen. "Modelling nitrogen emissions from soils fertilized with dairy slurry." Master's thesis, ISA-UL, 2016. http://hdl.handle.net/10400.5/13395.
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Mestrado em Engenharia do Ambiente - Instituto Superior de Agronomia - ULDiffuse nitrogen (N) emissions from agriculture have been increasing for the past decades constituting a major environmental problem. Instruments have been implemented during the last years such as legislations, technologies and measures to reduce emissions, but the diversity of the cropping systems allied with the complex diffuse N pathways resulted in an overall inefficiency of these instruments. As such, a holistic approach is needed, being the system modelling one important tool for that. The Root Zone Water Quality Model was tested for a sandy soil (Haplic Arenosol) and a sandy loam soil (Haplic Cambisol), cultivated with winter oats (Avena Sativa L.) fertilized with dairy slurry. Field data was collected at Horto de Química Agrícola of the Instituto Superior de Agronomia in Lisbon, consisting of soil water, temperatures and drainage from 2014 to 2016. Data from previous studies (2012 to 2014) relative to nitrate leaching and N2O emissions was also used. The model was then used for scenario analysis. For the winter oats in the sandy soil, the model predicted soil water and drainage with efficiencies of 86 and 94 % respectively, while for nitrate fluxes below the root zone and the N2O emissions to the atmosphere efficiency was 89 and 93% respectively. For the sandy loam system, the calibrated model yielded efficiencies of 87, 94, 62, 76 and 85%, for the control variables. Scenario analysis showed the occurrence of pollution swapping as the hydrologic year changed from very dry to wet, decreasing the N lost through gaseous emissions. As to the temperature scenarios results show that for this type of production systems, the most unfavourable climate change scenario was A1B1 (+4ºC) may produce an increase of 25 and 18 % in the N gas loss contributions for the sandy loam and the sandy soil respectively
N/A
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Vig-Dinescu, Ina-Mariana. "Tillage, rotation, and N fertilizer rate effects on surface soil physical properties." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0019/MQ37306.pdf.
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Vig-Dinescu, Ina. "Tillage, rotation, and N fertilizer rate effects on surface soil physical properties." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28031.
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In 1991, a project was initiated at Quinn and Ormstown, two sites with soils representative of Quebec's present-day agriculture. Three field management techniques were studied related to their possible impact on the soils: tillage, rotation, and N fertilization. The three treatments were randomly assigned in two blocks of a split-split-plot design. The main treatment, tillage, had two levels, conventional tillage (CT) and no-till (NT). The sub-treatment was represented by five 4-year rotations, starting from 1991 as follows: CCCC (continuous corn), CSAC (corn-soybean-alfalfa-corn), CSCS (corn-soybean-corn-soybean), SCSC (soybean-corn-soybean-corn) and SSSS (soybean monocrop). The third factor was N fertilization, at three different rates: 0, 90, and 180 kg/ha, excepting the continuous soybeans which received lower rates of, respectively, 0, 20 and 40 kg N/ha. Soil sampling was performed in 1994, during the last year of the 4-year rotations, at two different moments over the growing season, June and August, for all analysed soil properties, except aggregate stability and organic matter for which samples were taken only in September. (Abstract shortened by UMI.)
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Charteris, Alice Fiona. "¹⁵N tracing of microbial assimilation, partitioning and transport of fertilisers in grassland soils." Thesis, University of Bristol, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.720812.
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Mendes, Bastos Leonardo. "N fertilizer source and placement impacts nitrous oxide losses, grain yield and N use efficiency in no-till corn." Thesis, Kansas State University, 2014. http://hdl.handle.net/2097/18797.
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Master of ScienceDepartment of Agronomy
Charles W. Rice
Agricultural lands receiving N inputs are considered the primary source of N2O, a potent greenhouse gas. N fertilizer management has shown variable effects on both N2O losses and corn grain yield. The objectives of this study were to assess the impact of N source and placement on N2O emissions, fertilizer-induced emission factor (FIEF), corn grain yield, yield-scaled N2O emissions (YSNE) and N fertilizer recovery efficiency (NFRE). The experiment was conducted from 2013 through 2014 at the Agronomy North Farm located at Kansas State University, Manhattan, KS. The soil was a moderately well-drained Kennebec silt loam. The treatments were broadcast urea (BC-Urea), broadcast urea ammonium nitrate (UAN) (BC-UAN), broadcast coated urea (BC-CU), surface-band UAN (SB-UAN), subsurface-band UAN (SSB-UAN), subsurface-band UAN + nitrification inhibitor (SSB-UAN+I) and a 0 N control. In 2013, SSB- UAN emitted significantly more N2O (2.4 kg N2O-N ha-1), whereas control (0.3 kg ha-1) and BC- UAN (0.6 kg ha-1) emitted the least. In 2014, most treatments emitted between 3.3 and 2.5 kg N2O-N ha-1. Only SSB-UAN+I (1.03 kg ha-1) and control (0.26 kg ha-1) were significantly lower. The use of a nitrification inhibitor decreased N2O emissions by 62% and 55% in 2013 and 2014, respectively. BC treatments had cumulative emissions significantly higher in 2014 compared to 2013. Only SSB-UAN+I had a significantly lower FIEF (0.4%), and 2013 FIEF (0.68%) was significantly lower than that of 2014 (1.38%). In 2013, banded treatments had significantly higher grain yields (from 9.1 to 10.5 Mg ha-1), whereas in 2014 fewer differences among N treatments were observed, ranging from 7.2 to 8.6 Mg ha-1. Banded treatments had significantly lower grain yields in 2014 compared to 2013. Only BC-UAN and SSB-UAN+I had significantly lower YSNE, and 2013 had lower YSNE than 2014. In 2013, SSB-UAN had the greatest NFRE, whereas BC treatments had the lowest. In 2014, N treatments did not differ in NFRE. SSB-UAN and SSB-UAN+I had significantly lower NFRE values in 2014 compared to 2013. Fertilizer source and placement have the potential to mitigate N2O emissions and promote high yields and NFRE in corn, however, the response is dependent on the rainfall pattern after fertilizer application. The option of banding UAN without any additive promoted higher N2O losses on a year when precipitation was well distributed, but also enhanced grain yield and NFRE. On the other hand, under the same precipitation conditions, broadcasting N fertilizer promoted lower N2O losses, grain yield and NFRE, but those were all improved in a wet year. Therefore, the subsurface band placement would be the best option under a normal year, whereas broadcasting fertilizer would be the best option under a wetter year. Further, the use of NI with subsurface band UAN provides the most sustainable option, since the NI decreased N2O losses compared to UAN alone in both years. Further research should evaluate N source and placement combinations under different environments in order to better understand how they impact crop performance and the negative environmental aspects of N fertilization. It is important to test those treatments under different precipitation scenarios and look for trends that indicate the best N management option at the local level.
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Marx, Marie-Claude. "The study of hydrolytic enzymes in grassland soils with long-term N fertilizer management." Thesis, University of Reading, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413411.
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Riley, E. A., T. L. Thompson, S. A. White, and M. J. Ottman. "Tissue Testing Guidelines for N Management in Irrigated Malting Barley, Maricopa, 1999." College of Agriculture, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/205159.
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Malting barley is not a widely planted crop in the Southwest, due to grain protein contents that can sometimes exceed the industry standard of 11.4 %. To achieve < 11.4% grain protein, careful nitrogen (N) management is needed. Tissue testing guidelines for N management for reduced grain protein and acceptable yields have not yet been determined for malting barley in the Southwest. The objectives of this study were to: (i) correlate NO₃-N in dried stem tissue with sap NO₃-N, and (ii) develop stem NO₃-N guidelines for N management in malting barley. In November 1998 two varieties of malting barley, Morex and Crystal, were planted at the Maricopa Agricultural Center. Five N rates (0, 60, 120, 180, and 240 lbs/acre) were applied in four split applications. Each treatment was replicated three times in a randomized complete block design. Samples were collected from lower stems at the 3-4 leaf 2 node, and flag leaf visible growth stages. Grain yields ranged from 1011 lbs/A to 2677 lbs/A for Morex and 827 lbs/A to 2641 lbs/A for Crystal. Grain protein ranged from 6.94 -11.5% (Morex) and 8.48-13.0% (Crystal). Correlation coefficients between stem NO₃-N and sap NO₃-N were 0.83 for Morex and 0.85 for Crystal. For Morex and Crystal, grain protein was within the malting industry grain protein range of 10.5-11.4% and yield was optimized at 180 lbs N/A. Sap NO₃ analysis can be a useful tool for determining N status of malting barley.
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Mohamed, Abdellatif Abdellatif 1956. "Response of cotton to N and water applied via a trickle irrigation system : growth, yield, and nutrient uptake." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/191128.
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The crop growth rate (CGR); the relative growth rate (RGR); seed yield; plant uptake of N, P, K, Ca, Mg, Fe, and Na; and the water use efficiency (WUE) were studied in relation to N fertilizer and water application rate interactions in trickle-irrigated cotton. Increasing water application rate significantly increased CGR, but no significant differences were detected among the RGR values at the various water levels. Nitrogen fertilizer additions significantly increased the CGR. Nitrogen and water applications significantly increased seed yield, however, the effect of the interaction between N and water was not significant. Water levels had a positive significant effect on the cotton reproductive growth. Increased N and water significantly increased total N-uptake by cotton plants. Nitrogen additions significantly increased N% of leaves, burrs and seed. However, N% of stem was significantly reduced with high N applications. Total uptake of P, K, Ca, and Mg significantly increased with the increased application of N and water. Addition of 1.2 consumptive use (Cu) irrigation rate significantly increased P% in cotton stems, however, K% in stem was reduced. The irrigation rate of 0.9 CU and 1.2 CU significantly increased Mg% in both leaves and stems. Nitrogen application rates of 224 and 336 kg N/ha significantly decreased Mg% in leaves and stems. Increasing the irrigation rate from 0.9 CU to 1.2(1.3) CU reduced the WUE by cotton plants. However, WUE appeared to increase as N fertilizer increased up to 33 kg N/ha with water level of 0.9 CU.
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Zhang, Feng 1962. "Effects of N formulation, application rate, and application time on corn yield and quality in eastern Canada." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61039.
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An experiment was conducted to investigate the effects of N formulation, application rate, and application time on corn yield and quality under Eastern Canadian conditions, to evaluate the hypothesis that application of N will increase corn grain yield and protein concentration without decreasing the total energy content. Three N formulations, each with the rates of 90, or 180 kg ha$ sp{-1}$ were applied at different times. The results indicated that the grain yield increased with increasing N fertilizer rate and with increasing numbers of N application times. N application significantly increased grain protein concentration, on both a per kernel and a dry matter basis, and protein yield. Such as, N application increased the averaged protein concentration, on a dry matter basis, of corn grain by about 8.40% as compared to the control. The protein concentration was not affected by the number of N application times before the plants were 90 cm high. Neither lipid nor non-structural carbohydrate concentration, on both a per kernel and a dry matter basis, were significantly affected by N application in most of the location-years. In addition Near infrared reflectance (NIR) was used to determine the lipid concentration in the aerial corn tissue at different growth stages. The correlation coefficients between the standard analytical method and the NIR method of lipid concentration were all above 0.95, and were significant at 0.01 level.
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Seman-Varner, Rachel Nicole. "The role of cover crops in agroecosystem functioning." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/83232.
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Current interest in cover cropping is focused on enhancing ecosystem services beyond soil conservation. Cover crop (CC) species function uniquely in their effects on ecosystem services when grown in monoculture or mixtures. This research integrated field experiments and a literature synthesis to evaluate the role of cover crops in improving nitrogen (N) management and simultaneously providing multiple ecosystem services. Legume CC fertilized with poultry litter (PL) could replace 101 to 117 kg N ha-1 of fertilizer in corn (Zea mays L.) production. Rye (Secale cereale L.) CC fertilized with PL had a negligible effect on corn production. Biculture fertilizer equivalence ranged between -12 to +75 kg N ha-1. Fertilizer equivalence of legume-containing treatments increased across time. Without CC, fall-applied PL failed to supply N to corn. Ecosystem services of CC and PL illustrate complex species functions. Bicultures produced more total biomass than monocultures in year 1 but less than rye in year 2. Bicultures were as effective in suppressing weeds as rye, produced corn yield similar to legume, and by the second year had similar amounts of available soil N as the legume. Poultry litter effects and interspecific effects cover crop species biomass differed. Rye yield increased, while legume yield decreased slightly in biculture. Poultry litter increased legume N content and a decrease in legume C:N, while rye N content and C:N were unaffected. The synthesis corroborates that mixed and biculture cover crops yield more than the individual component species. Overyielding was transgressive in 60% of cases studied. Mixture effects varied by species: rye and brassica yield increased, while legume decreased in mixtures. The effect of mixed CC on crop yields varied by crop species and management practices, though generally crops increased 8 to 18% overall. This work can be applied to the design of complex CC and PL systems that optimize individual species functions to enhance ecosystem services.Ph. D.
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Ervin, Clara Ray. "Poultry Litter Ash as an Alternative Fertilizer Source for Corn." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/103199.
Full textAbstract:
Poultry litter ash (PLA) is a co-product from manure-to-energy systems that originated in response to increased poultry litter (PL) volumes generated in concentrated poultry production regions. Investigating PLA as a crop fertilizer is an alternative solution to balancing poultry and crop regional nutrient cycling in the Commonwealth of Virginia. As the expanding world population places pressure on the poultry industry to meet consumption demands, increased PL production presents an obstacle to identify alternative uses for increased volumes. Currently, Virginia produces 44 million broilers with PL produced predominately in the Shenandoah Valley and Eastern Shore. Likewise, a growing world population places pressure on crop production areas and subsequently finite natural resources used for crop fertilization. Poultry litter ash is an alternative phosphorus (P) and potassium (K) source enhancing transportation logistics, repurposing PL nutrients, and offers dual purpose as a fertilizer and an energy source when compared to PL.
Three PLA products [(fluidized bed bulk (FB Bulk), fluidized bed fly (FB Fly), and combustion Mix (CMix)], two manufactured co-products [(granulated poultry litter ash (GPLA), and ash coated urea (ACU)] were evaluated as P, K, and N sources for corn (Zea Mays L.) production in comparison to industry fertilizers [(PL, triple superphosphate (TSP), muriate of potash (KCL), and urea). A comprehensive examination of elemental composition, P speciation, P and K solubility, improved functionality into granulized forms, and field testing were conducted to discern PLA potential as an alternative fertilizer source.
Poultry litter ash products were evaluated by total elemental analysis, backscatter-electron dispersive (BSED) microscopy, and X-ray absorption near edge structure (XANES) spectroscopy. Poultry litter ash elemental concentrations were highly variable ranging from 50.6 to 102.0 g P kg -1 and 62.6 to 120.0 g K kg -1 and were comparatively higher than PL concentrations. Phosphorus structures that provided and controlled P solubility were Ca and Ca-Mg-phosphate compounds. Spectroscopy confirmed Ca structures as predominately monetite (dicalcium phosphate anhydrous; CaHPO4; log K ̊ 0.30) and brushite (dicalcium phosphate dihydrate; CaHPO4.2H20; 0.63 log K ̊ ) species that were supported by BSED and elemental stoichiometric ratios (Ca:P; 1.12 to 1.71:1). Additionally, GPLA acidified from FB Fly had higher brushite and monetite percentages described by spectra models, translating into a more soluble Ca-phosphate species when compared to FB Fly original P species.
Granulated poultry litter acidulation trials successfully identified a desired granulation point of 29% (14.5 g acid to 50 g PLA) phosphoric acid (75% H3PO4) acidulation. Acidulation dose response relationships created simple linear regression (SLR) equations that sufficiently (R2 > 0.80) described changes in total measurable P and water soluble P, pH, and exothermic reaction temperatures to increasing H3PO4 acidulation. Solubility tests included: sequential extraction, particle size effect on solubility, carbon effect on water soluble P, and Mehlich-1 extraction of PLA sources that confirmed decreased P solubility. A majority PLA P was found in bound plant unavailable fractions (87.7 to 97.7% P of total P). Granulated poultry litter ash had improved P plant available P of 36.0% P of total P. Carbon (C) effects on PLA P were examined by ashing PLA samples in a muffle furnace at 550 ̊C. Differences in total carbon content negatively impacted FB Bulk and CMix total P (1.30 and 4.56 g P kg -1); however, muffle furnace temperatures increased FB Fly total P by 6.74 g P kg -1.
All fertilizer products were investigated under field conditions in separate P, K and N corn studies across Virginia coastal plain soils to determine fertilizer effects on corn plant parameters [(most mature leaf (V6), corn ear leaf (R1), and grain (R6)]. Poultry litter P treatments, averaged over rate, recorded highest yield in both years. At eight of nine field sites, FB Bulk resulted in numerically or significantly higher Mehlich-1 concentrations than other P sources post-harvest. Although Mehlich-1 P increased, yield and plant parameters did not; which leads to the conclusion that PLA sources increased soil residual P that did not translate into immediate plant availability recorded within a growing season. Across plant efficacy parameters examined, PLA K is a comparable nutrient source and improved plant parameters when compared to control. Eighteen out of twenty-one plant parameters examined found similar ACU and urea effects on N concentrations. Therefore, ACU is a comparable N source to urea. When compared to industry fertilizer sources, we concluded that PLA is a slowly available P source, decreased P availability negatively affected early plant growth, K is a comparable nutrient source and improved plant parameters compared to control, and ACU effectively provided N to maintain sufficient corn growth. In conclusion, PLA co-products serve as a densified nutrient source that may provide plant available nutrients if processed to aid in nutrient distribution to grain producing areas.Doctor of Philosophy
Poultry litter ash (PLA) is a co-product from manure-to-energy systems that originated in response to increased poultry litter (PL) volumes generated in concentrated poultry production regions. Investigating PLA as an alternative crop fertilizer is essential to balancing poultry and crop regional nutrient cycling in the Commonwealth of Virginia. As the expanding world population places pressure on the poultry industry to meet consumption demands, heightened PL production presents an obstacle to identify alternative uses for increased volumes. Currently, Virginia produces 44,683,904 broilers with PL produced predominately in the Shenandoah Valley and Eastern Shore. Likewise, a growing world population places pressure on crop production areas and subsequently finite natural resources used for fertilization vital to maintaining crop yields. Poultry litter ash, a co-product from manure-to-energy systems, is an alternative phosphorus (P) and potassium (K) source enhancing transportation logistics, repurposing PL nutrients, and offers dual purpose as a fertilizer and an energy source when compared to PL. In this dissertation, three PLA products [(fluidized bed bulk (FB Bulk), fluidized bed fly (FB Fly), and combustion Mix (CMix)], two manufactured co-products [(granulated poultry litter ash (GPLA), and ash coated urea (ACU)] were evaluated as P, K, and N source for corn (Zea Mays L.) production in comparison to industry fertilizers (PL, triple superphosphate (TSP), muriate of potash (KCL), and urea). Each of the following chapters provides a comprehensive examination of the following topics: elemental composition, P speciation, P and K solubility, improved functionality into granulized forms, and field testing designed to provide parameters to conclude PLA potential as an alternative P, K and N source. In the second chapter, PLA products were evaluated by total elemental analysis, backscatter-electron dispersive (BSED) microscopy, and X-ray absorption near edge structure (XANES) spectroscopy. Poultry litter ash elemental concentrations are highly variable and are comparatively higher than PL concentrations. Phosphorus structure and species identified Ca as the primary element controlling P structure and subsequent solubility. The third component of this dissertation is granulation trials investigating phosphoric acid effects on granulizing and increasing total and water soluble P. Our results identified 29% (14.5 g acid to 50 g PLA) phosphoric acid acidulation for desired granule size. The third dissertation component examines PLA solubility. The results demonstrated PLA decreased P water solubility when compared to industry fertilizer sources. Granulated poultry litter ash demonstrated improved P plant availability due to the granulation process. The final and fourth dissertation components investigated PLA sources under field conditions in separate P, K and N corn studies across Virginia coastal plain soils to determine fertilizer effects on corn plant parameters. Minority of plant parameters tested revealed P control yielded numerically higher P concentrations than PLA P sources tested. Poultry litter P treatments, averaged over rate, recorded highest yield in both years. At eight of nine field sites, FB Bulk resulted in numerically or significantly higher Mehlich-1 concentrations than other P sources post-harvest. Although Mehlich-1 P concentrations increased, yield and plant parameters did not; which leads to the conclusion that PLA sources increased soil residual P that did not translate into immediate plant availability recorded within a growing season. Across plant efficacy parameters examined, PLA K is a comparable nutrient source and improved plant parameters when compared to controls. The majority of plant parameters examined found similar ACU and urea effects on N concentrations. Therefore, ACU is a comparable N source to urea. When compared to industry fertilizer sources, field results concluded that PLA is a slowly available P source, decreased P availability negatively affected early plant growth, K is a comparable nutrient source and improve plant parameters compared to control, ACU effectively provides N to maintain sufficient corn growth. In conclusion, PLA co-products serve as a densified nutrient source that may provide plant available nutrients if processed to aid in nutrient distribution to grain producing areas.
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Rech, Ioná. "Produção e avaliação da eficiência de ureia enriquecida com aditivos para o controle da liberação do nitrogênio." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-19032014-111122/.
Full textAbstract:
Devido à importância do aumento da eficiência agronômica dos fertilizantes nitrogenados em função do custo cada vez maior dos fertilizantes na produção agrícola, o objetivo do presente estudo foi desenvolver formulações de fertilizantes nitrogenados a base de ureia com a adição de compostos inibidores de urease (NBPT, Cu, B), enxofre elementar e um argilomineral do grupo das zeolitas compondo os grânulos internamente, a fim de minimizar as perdas de N por volatilização de amônia e por lixiviação de amônio e nitrato. O primeiro experimento foi conduzido em casa de vegetação entre janeiro e março de 2013, no departamento de ciência do solo da ESALQ, onde foram avaliadas dez formulações produzidas no Laboratório de Tecnologia de Fertilizante da Embrapa Solos, mais alguns fertilizantes comerciais (FH Nitro Mais®, FH Nitro Gold®, Super N®, sulfato de amônio e ureia). Colunas de PVC com 15 cm de diâmetro por 45 cm de altura foram montadas e preenchidas com amostra de um Latossolo Vermelho Amarelo de textura média. A volatilização de amônia foi determinada através de uma câmara semi-aberta estática instalada na parte superior de colunas. A avaliação da lixiviação do nitrato e amônio foram feitas ao final do experimento de volatilização por meio da percolação de água, simulando chuva de 15 mm por 4 dias consecutivos, nestas mesmas colunas. Em seguida foi realizada coleta de solo nas camadas de 0-10, 10-20 e 20-45 cm com a finalidade de quantificar o teor de amônio e nitrato acumulado no perfil. Em outro experimento, conduzido em casa de vegetação entre abril e maio de 2013, foi testada a eficiência de uso de N pelas plantas de milho com quatro formulações produzidas e três fertilizantes comerciais, os quais apresentaram as menores perdas de N por volatilização, acrescidos do tratamento ureia comercial e controle, sendo avaliado o N acumulado e a massa seca produzida pelo milho cultivado em vasos com 6 kg de solo. As formulações produzidas com inibidores de urease (NBPT, B, Cu) incorporado nos grânulos e estes combinados com o argilomineral apresentaram maior eficiência na redução das perdas de N por volatilização em comparação aos fertilizantes comerciais com tecnologia de revestimento desses inibidores. Os resultados da lixiviação de amônio e nitrato e o acúmulo desses íons no solo não apresentaram diferenças expressivas entre os fertilizantes produzidos e os comerciais. O acúmulo de N nas plantas com a adubação referente aos fertilizantes produzidos foi similar aos fertilizantes comerciais, porém superior à ureia comercial. No entanto, é possível afirmar que a incorporação de inibidores de urease na ureia é mais eficiente na redução das perdas de N por volatilização, comparado aos fertilizantes produzidos com a tecnologia de revestimento desses mesmos aditivos.Due to the importance of increasing the agronomic efficiency of nitrogen fertilizers and the increasing fertilizer costs in agricultural production, the aim of this study was to develop urea-based formulations of nitrogen fertilizer with the addition of urease inhibitors (NBPT, Cu, B), elemental sulfur and clay minerals of the zeolite group, composing beads internally to minimize N losses by volatilization and leaching of ammonium and nitrate. The first experiment was conducted in greenhouse from January to March 2013 in the Department of Soil Science of ESALQ, where was assessed ten formulations produced in the Fertilizer Technology Laboratory of Embrapa Solos and some commercial fertilizers (FH Nitro Mais®, FH Nitro Gold®, Super N®, ammonium sulfate and urea). PVC columns with 15 cm in diameter and 45 cm in height were assembled and filled with soil samples of Latossolo Vermelho Amarelo medium-texture. Ammonia volatilization was determined using a semiopen static chamber installed on the top of columns. Evaluation of nitrate and ammonium leaching was taken at the end of the volatilization experiment by water percolation, simulating a rain of 15 mm for 4 consecutive days. Furthermore, soil samples were collected at 0-10, 10- 20 and 20-45 cm depth layers in order to determine the concentration of ammonium and nitrate accumulated in the profile. Another experiment, conducted in greenhouse from April to May of 2013, was carried out to test N use efficiency by corn plants with four produced formulations and three commercial fertilizers which obtained the lowest N losses by volatilization, including urea and a control treatment, being assessed N accumulated and dry matter produced by corn grown in pots with a volume of 6 kg. The formulations produced with urease inhibitor alone (NBPT, B, Cu) embedded in beads and those inhibitors combined with the clay mineral showed greater efficiency in reducing losses by volatilization compared to commercial coated fertilizer with the same inhibitors. Ammonium and nitrate leaching and soil accumulation showed no significant differences between produced formulations and commercial fertilizers. The N accumulation in corn plants grown with the new formulations was similar to commercial fertilizer, being higher to commercial urea. However, it is clear that the incorporation of a urease inhibitor in urea fertilizer is more efficient in the reduction of losses by volatilization compared to coated fertilizers produced with the same additives.
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Rembon, Fransiscus Suramas. "Impact of no-tillage versus conventional tillage, soybean-corn rotations, and fertilizer N rates on soil N levels and grain yields in two Eastern Canadian soils." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22794.
Full textAbstract:
Corn (Zea mays L.) production under monoculture and conventional-tillage management may cause soil degradation and nitrate (NO$ sb3 sp-)$ pollution. This study was conducted from 1991 to 1993 to evaluate the impact of conventional-tillage (CT) and no-tillage (NT) practices under corn-soybean (Glycine max L. Merill) rotations (C-S-C and S-C-S), continuous corn (C-C-C) and continuous soybean (S-S-S) systems on optimum N fertilization rates, yield and soil residual N levels. Field experiments were carried out on a Ste. Rosalie clay (Humic Gleysol) and an Ormstown silty clay loam (Humic Gleysol). Overall, tillage had little effect on soil and crop N levels or grain yields. Residual soil NO$ sb3$-N in the fall was related to fertilizer N rates in C-C-C, but not with S-S-S or soybean in rotation. Residual NO$ sb3$-N values after soybean were high and at zero added N were equivalent to 90 kg N with C-C-C. Consequently, soybean contributed the equivalent of 90 kg N ha$ sp{-1}$ to subsequent corn. Corn yields following soybean were higher than following corn, and less fertilizer N was required following soybean than following corn.
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Andrade, Marta Maria Santos de Jesus. "Programs of profit sharing and results - law n. 10.101/2000 and functional comprometimento in bahian fertilizer industries." Universidade Federal do CearÃ, 2007. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=3529.
Full textAbstract:
nÃo hÃThe objective of the present research is to evaluate the relative importance of the Program of Participation in Profits and Results (PPLR) â Law number 10.101, for the commitment of employees in comparison with other factors of functional commitment. Exploratory and descriptive research was conducted, through case studies, with the use of a questionnaire middle structured questionnaire and an interview by topic with managers of PPLR and employees of the administrative, commercial, and operational areas of two large fertilizer companies in Bahia. The research involved two managers and seventy nine employees. The results were analyzed quantitatively and qualitatively. The research allowed to confirm that in spite of the importance of the PPLR for organizational strategies and objectives, there was no agreement between the companies in what it concerns to the prevalence of the Program when related to factors of affective, normative compromising and other calculatives related in the study. It is suggested that several aspects compete for the dissonance among the case studies researched, as the geographical location, demographic subjects and the style of the administration.
A presente pesquisa tem como objetivo avaliar a importÃncia relativa do Programa de ParticipaÃÃo nos Lucros e Resultados (PPLR) â Lei no. 10.101, para o comprometimento dos empregados em comparaÃÃo com outros fatores de comprometimento funcional. Realizou-se uma pesquisa exploratÃria e descritiva, por meio de estudo de caso mÃltiplo, com a aplicaÃÃo de um questionÃrio semi-estruturado e uma entrevista por pauta, junto a gestores dos PPLR e empregados das Ãreas administrativa, comercial e operacional de duas grandes empresas de fertilizantes da Bahia. A pesquisa envolveu dois gestores e setenta e nove empregados. Os dados foram tratados quantitativa e qualitativamente. A pesquisa permitiu constatar que, apesar da importÃncia dos PPLR para as estratÃgias e objetivos organizacionais, nÃo houve consenso entre as empresas pesquisadas no que concerne à prevalÃncia do Programa quando relacionado com fatores de comprometimento afetivos, normativos e demais calculativos relacionados no estudo. Sugere-se que vÃrios aspectos concorrem para a dissonÃncia entre os estudos de caso pesquisados, como a localizaÃÃo geogrÃfica, questÃes demogrÃficas e o estilo da gestÃo.
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Nabati, Daryoosh A. "Responses of two grass species to plant growth regulators, fertilizer N, chelated Fe, salinity and water stress." Diss., Virginia Tech, 1991. http://hdl.handle.net/10919/39783.
Full textAbstract:
A series of studies were initiated to investigate growth responses of Kentucky bluegrass (Poa praetensis L.) and creeping bentgrass (Agrostis palustris Huds.) to foliar applications of two plant growth regulators (PGR) and/or chelated Fe (Na Fe diethylene triamine pentaacetate). Environmental variables considered were N levels, soil moisture regimes, and saline irrigations.
The two materials investigated for PGR properties were a commercial product called Roots (a cold-water extract of seaweed and peat humus fortified with "intermediate metabolites" and thiamine) and the systemic fungicide propiconazole, trade name: (Banner) and chemical name: [1- {(2-(2,4-dichlorophenyl)-4-propyl-l,3-dioxolan-2yl}methyl-l H-1,2,4-triazole]. Fortified seaweed extract (FSE) was applied at 9.3 L/ha, and propiconazole (PPC) was applied at 0.93 L a.i/ha. Each was applied alone or in conjunction with chelated Fe at 0.11 kg a.i/ha.
Kentucky bluegrass foliage height, root and shoot dry weight, and several foliar nutrients increased following PGR treatments when grown under either limited soil moisture or saline irrigation.
Foliar applications of PGR and/or chelated Fe to creeping
bentgrass reduced wilting and evapotranspiration, and increased leaf water status, root strength, and shoot dry matter at two levels of N during and after drought stress.Ph. D.
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Heumann, Sabine [Verfasser]. "Net N mineralization in agricultural soils : experimentally parameterized modelling for N fertilizer recommendations and inhibition effects in soils with specific former land-uses / Sabine Heumann." Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2019. http://d-nb.info/1179909232/34.
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Oliveira, Sueyde Fernandes de. "Use efficiency of controlled release fertilizer on the growth of croton and petunia and N loss by leaching." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-10052016-134408/.
Full textAbstract:
The market of flowers and ornamentals such as croton (Codiaeum variegatum) and petunia (Petunia×hybrida Vilm.-Andr) have been created new technologies to constantly development, as one of the most promising segments of horticulture. Fertilization providing adequate nutrition and less leaching to the environment is the objective of numerous studies around the world. Therefore, two studies were conducted to evaluate the use of controlled release fertilizer (CRF) on the growth of two ornamental species, and N loss by leaching. The first experiment aim to evaluate sources and rates of CRF and water soluble fertilizer (WSF) on croton growth and nitrogen concentration on drained solution. Results showed that treatments with WSF and low rates of CRF provided higher plants growth, and the amount of N leached was higher for WSF treatments. The second experiment objective to compare plant performance and cost for strategies that potentially provide adequate nutrition during both the production and consumer phases for container-grown Petunia plants. In addition, two experiments were conducted to evaluate nutrient release in sand containers inside of the greenhouse and under controlled temperature conditions without plants. Results showed that during production phase all fertilizer treatments produced high quality plants, and during consumer phase, plants grown with WSF only during the production phase were nutrient-deficient, while plants receiving CRFs were still growing vigorously, especially in a high rate. The release rates of all CRF products were temperature-dependent. In conclusion CRF provided plant growth at the same rate that WSF, with less N leaching and extra cost less than U$0.065 per plant with CRF during production.O mercado de flores e plantas ornamentais tais como cróton (Codiaeum variegatum) e petúnia (Petunia×hybrida Vilm.-Andr) apresenta-se em constante desenvolvimento tecnológico, caracterizando-se como um dos mais promissores segmentos da horticultura. A adubação, visando o aumento da eficiência do fertilizante e redução de perdas, são temas de estudos em todo o mundo. Assim, foram realizados dois experimentos para avaliar o uso de fertilizantes de liberação controlada (FLC) no crescimento de duas espécies de plantas ornamentais e a perda de nitrogênio por lixiviação. O primeiro experimento teve como objetivo avaliar fontes e doses de FLC e solução nutritiva no crescimento de cróton e a concentração de nitrogênio (N) na solução drenada dos vasos. Os resultados revelaram que a solução nutritiva e as menores concentrações de FLC proporcionaram o maior crescimento das plantas, e as taxas de N perdidas por lixiviação foram superiores para o tratamento com solução. O segundo experimento objetivou comparar estratégias de adubação que proporcionem nutrição adequada durante a fase de produção e do consumidor com menor custo, as quais incluíam FLC e solução nutritiva. Simultaneamente, foram realizados dois experimentos para avaliar a liberação de nitrogênio pelos fertilizantes, sem as plantas, nas condições de cultivo das plantas (estufa) e em câmaras de crescimento sob três temperaturas de incubação. Os resultados mostraram que durante a fase de produção todos os tratamentos resultaram em plantas nos padrões comerciais, e no período que simulou a fase do consumidor as plantas que receberam apenas solução nutritiva durante a fase de produção apresentaram deficiência nutricional, enquanto com os FLC as plantas cresceram vigorosamente, principalmente para os tratamentos com as maiores doses. Os fertilizantes avaliados apresentaram diferença quanto à temperatura na liberação dos nutrientes, sendo maior a taxa de liberação quanto maior a temperatura. De acordo com os resultados o FLC proporcionou o crescimento das plantas na mesma proporção que a solução nutritiva, com uma redução na concentração de N por lixiviação e acréscimo inferior a U$0.065 no custo por planta quando utilizado FLC durante a produção.
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Lewis, Emily Kathryn. "Assessment of Spectral Reflectance as Part of a Variable-Rate Nitrogen Management Strategy for Corn." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/44620.
Full textAbstract:
Spectral reflectance-based, remote sensing technology has been used to adjust in-season nitrogen (N) fertilizer rates for wheat to account for spatial variability in grain yield potential at a sub-meter resolution. The objective of this study was to examine the relationships among spectral reflectance indices, corn tissue N content, chlorophyll measurements, plant size and spacing measurements, and grain yield to develop a similar strategy for variable-rate N management in corn. Irrigated and non-irrigated studies were conducted during the 2002 and 2003 growing seasons in eastern Virginia. Plots were treated with various rates of preplant, starter, and sidedress N fertilizer to establish a wide range of grain yield potential. Spectral measurements, tissue N, chlorophyll measurements, and plant physical measurements were collected at growth stages V6, V8, and V10. At maturity, grain yield was determined and correlated with in-season data and optimum N rate to calibrate in-season, variable-rate N fertilization strategies. Results from these studies indicate that spectral reflectance is well correlated with plant N uptake and chlorophyll meter readings and can also be correlated with final grain yield. These relationships may be used to develop a model to predict in-season, variable N application rates for corn production at a sub-meter resolution.Master of Science
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Shen, Juecui. "Microbial communities and enzyme activities related to C and N cycling in fertilized and unfertilized forests." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/23239.
Full textAbstract:
The study was conducted at the fertilization demonstration plots of the Salal Cedar Hemlock Integrated Research Program. PH, moisture, N availability (NO₃⁻ and NH₄⁺), microbial biomass C,N and P, phospholipid fatty acids (PLFA), and enzyme activities were measured in the forest floor and mineral soil of western red cedar stands and western hemlock stands ten years following fertilization with N or P, or both.
Results showed that forest floor had the largest effect on microbial and soil chemical variables, followed by forest type, and fertilization. N fertilization significantly increased overall bacterial PLFA abundance and reduced fungal PLFA abundance, while P fertilization significantly reduced AM fungal abundance in the organic layer of the hemlock stands. In addition, the stimulatory effect of N fertilization and inhibitory effect of P fertilization on phosphatase activity was still apparent 10 years after fertilization. Moreover, the effect of fertilization on microbial communities was more pronounced in the forest floor than at depth in the soil. Correlations between microbial community structure and function were weak.
After 10 years, fertilization had not inhibited enzyme activities related to lignin decomposition, but had a significant effect on microbial community composition. Future effort should be directed to long-term and in situ research to understand microbial processes at a fundamental level, as well as linking this research with external factors, such as C costs related to fertilization treatment and shorted rotation length, to understand how microbial processes contribute to the bigger picture of C cycle related with forestry.
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STAFANATO, Juliano Bahiense. "Perdas por volatiliza??o de N-NH3 e avalia??o de fertilizantes nitrogenados contendo micronutrientes na cultura do milho (Zea mays)." Universidade Federal Rural do Rio de Janeiro, 2013. https://tede.ufrrj.br/jspui/handle/jspui/1540.
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CAPES
This study aimed to evaluate the dynamics of nitrogen losses by volatilization of ammonia from urea fertilizers pelletized with different micronutrients (zinc, copper and boron), and to evaluate possible residual effect of these nutrients as well as the effect on the growth and development of corn (Zea mays) plants. The studies took place in a greenhouse at the experimental area of the Soils Department of Federal Rural University of Rio de Janeiro. The soil used in this study was sampled from surface horizon of a Fragiudult soil and had sandy texture. For testing volatilization and residual effect of nitrogen two doses (100 and 200 kg ha-1) were applied. The fertilizers were evaluated for N losses for a period of 21 days. After the period of the N losses evaluation, corn seeds were planted in the same soil, to assess the residual effect of these pelletized fertilizer containing micronutrients. After these two experiments, they were selected, among the 15 pelletized urea formulas, 9 products that showed the best results, especially those which resulted in decreasing N losses by volatilization. These products were then evaluated for their effect on growth and development of corn plants, using the variety Sol da Manh?. The amount of the micronutrient boron in the pelletized urea positively influenced the reduction of N losses by NH3 volatilization, particularly when in higher concentration (4.0% B), reducing N losses by 50% (rate of 100 kg ha-1) and 64 % (dose of 200 kg ha-1) compared to the pearly urea. In general, the pelletized urea containing micronutrients, especially B, single or associated with Zn and Cu, showed to be a promising alternative for new fertilizers, with the goal of reducingN losses by volatilization. There was no effect of the different nitrogen fertilizers application as for increasing residual N in the soil. The application of the pelletized urea containing Zn, Cu and B micronutrients, single and / or associated, increased their quantities in the soil. The largest additions of the micronutrients Zn, Cu and B in the soil, using the pelletized urea, consequently, reflected in greatest amounts of these elements in the maize plant. The addition of zinc by application of pelletized urea did not show positive effect in the growth of corn plant as expected. Possibly, due to zinc quantities in the soil sufficient to supply the plants requirement. The presence of boron in the pelletized urea influenced the accumulation of N in the plants, especially for B concentrations in the fertilizer above 2.0 %.
Este trabalho teve como objetivo avaliar a din?mica de perdas de nitrog?nio por volatiliza??o da am?nia oriundo de fertilizantes pastilhados de ureia com diferentes micronutrientes (zinco, cobre e boro), avaliando o poss?vel efeito residual destes nutrientes como tamb?m seu efeito sobre o crescimento e desenvolvimento de plantas de milho (Zea mays). Os estudos foram realizados em casa de vegeta??o localizada na ?rea experimental do Departamento de Solos da UFRRJ. O solo utilizado neste trabalho foi proveniente de um horizonte superficial de um Planossolo H?plico (textura arenosa). Para o ensaio de volatiliza??o e efeito residual foram utilizados duas doses de N (100 e 200 kg ha-1), onde os diferentes fertilizantes foram avaliados quanto as perdas de N por um per?odo de 21 dias. Ap?s o per?odo de avalia??o das perdas de N foram plantadas no mesmo solo, sementes de milho com intuito de avaliar o efeito residual destes fertilizantes pastilhados contendo micronutrientes. Ao t?rmino destes dois ensaios, foram ent?o selecionados dentre os 15 pastilhados de ureia, 9 produtos que apresentaram os melhores resultados, principalmente aqueles que resultaram em maiores redu??es nas perdas de N por volatiliza??o, que foram ent?o avaliados quanto ao seu efeito no crescimento e desenvolvimento de plantas de milho, variedade Sol da Manh?. O micronutriente boro presente nos pastilhados de ureia influenciaram positivamente na redu??o das perdas de N-NH3 por volatiliza??o, principalmente quando presente na maior concentra??o (4,0% B), reduzindo as perdas de N em 50% (dose de 100 kg ha-1) e em 64% (dose de 200 kg ha-1) as perdas em rela??o a ureia perolada. De forma geral, os pastilhados de ureia contendo micronutrientes, principalmente B de forma isolada e/ou associado com Zn e Cu demonstraram ser uma alternativa promissora de novos fertilizantes com objetivo de reduzir as perdas de N por volatiliza??o. N?o houve efeito da aplica??o dos diferentes fertilizantes nitrogenados em aumentar as quantidades residuais de N no solo. A aplica??o dos pastilhados de ureia contendo os micronutrientes Zn, Cu e B isolados e/ou associados aumentaram as quantidades destes no solo. As maiores adi??es dos micronutrientes Zn, Cu e B no solo via ureia pastilhada refletiram-se, consequentemente, em maiores quantidades destes elementos na planta de milho. A adi??o de zinco via aplica??o de ureia pastilhada n?o apresentou efeito positivo em incrementar o crescimento da planta de milho como esperado. Possivelmente, pois as quantidades de zinco no solo foram suficientes para suprir as necessidades das plantas. A presen?a de boro nos pastilhados de ureia influenciaram o ac?mulo de N nas plantas, principalmente para concentra??es de B no fertilizante acima de 2,0%.
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Scharf, Peter Clifton. "Development of field-specific spring N rate recommendations for winter wheat." Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/40078.
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Schindler, Frank Vincent. "Redistribution and fate of applied ??N-enriched urea under irrigated continuous corn production." Thesis, North Dakota State University, 1996. https://hdl.handle.net/10365/28973.
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Understanding the redistribution and fate of N is essential for justification of Best Management Practices (BMP). This project was conducted on a Hecla fine sandy loam (sandy, mixed, Aquic Haploboroll) soil at the BMP field site near Oakes, North Dakota. One objective of this investigation was to evaluate the residence times of N03- -N in 20 undisturbed lysimeters and its infiltration time through the soil profile to tile drains. Corn (Zea mays L.) was fertilized with 135 kg N ha -1 as ??N-enriched urea plus 13.5 and 48.1 kg N ha -1 preplant for 1993 and 1994, respectively. Urea-N was band applied to 20 and 10 undisturbed lysimeters at 2.0 and 5.93 atom percent (at %) ??N in 1993 and 1994, respectively. Average resident times of N03- -N in the lysimeters was 11.7 months. Lysimeter and tile drainage indicate the presence of preferential pathways. Residence times of N03- -N depend on frequency and intensity of precipitation events. Another objective was to determine what portion of the total N in the crop was from applied urea-N and what portion was from the native soil-N. Nitrogen plots received ??N enrichments of 4.25 and 5.93 at % ??N in 1993 and 1994, respectively. At the end of the 1993 and 1994 growing season, 41.5% and 35.7% of the labeled fertilizer N remained in the soil profile, while the total recovery of applied ??N in the soil-plant system was 86.2% and 75.4%, respectively. Low recoveries of applied N may have been the result of soil or aboveground plant biomass volatilization, or denitrification or preferential flow processes. Further research needs to be conducted with strict accountability of gaseous loss and the mechanism(s) responsible.U.S. Bureau of Reclamation
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Buyarski, Christopher R. "Photosynthetic capacity of deciduous tree species growing in the Duke FACE experiment with elevated CO₂ and N fertilization." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5677.
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Koetlisi, Andreas. "Influence of soil texture, water management and fertilizer N on the biomass production and antimicrobial properties of Mentha longifolia L." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/79999.
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Thesis (MScAgric)--Stellenbosch University, 2013.ENGLISH ABSTRACT: Soil texture, plant available water and fertilizer N would influence growth, biomass production and antimicrobial properties of locally used medicinal plants.This research was aimed at investigating how various soil textures (loamy sand, sandy loam and loam) with varying amounts of plant available water (PAW) and nitrogen fertilizer rates would influence the biomass production and antimicrobial properties of Mentha longifolia L. In this research, a two-way factorial experiment was used. It was produced by 3 X 3 factors, viz. three different soil textures (loam, sandy loam and loamy sand) and three levels of PAW in the first trial (0 %, 50 % and 90 % depletion of PAW) and three levels of N fertilizer rates in the second trial. The elemental fertilizers KNO3, K2SO4, KH2PO4, KCl Ca (NO3)2.2H2Oz, CaSO4.2H2O and Mg SO4.7H2O were used to prepare a nutrient solution for fertigation to meet 0Kg ha-1, 150Kg ha-1 and 250Kg ha-1 fertilizer N. This was replicated four times. The experiment was conducted in a tunnel. From the first trial the highest biomass production was obtained from 0% depletion of PAW treatments whereas 50% and 90% depletion of PAW matched each other at lower biomass productions. In terms of soil texture a higher biomass production was gained from loamy sand followed by loam and sandy loam. In the second trial similar influences of soil texture were evident and the significant biomass productions were highest, intermediate and low from 250Kg ha-1, 150Kg ha-1 and 0Kg ha-1 of fertilizer N, respectively. Accordingly, Mentha longifolia L revealed a minimal bacterial inhibition activity at 20g 100ml-1 against Staphylococcus aureus (gram positive bacteria) under Minimum Inhibitory Concentration assay–susceptibility test. It was therefore concluded that soil texture does influence biomass production. In a like manner, the PAW had a significant impact on the total biomass production. An increase in N fertilizer increased vegetative biomass production. Plant material obtained from Mentha longifolia L has antimicrobial properties. Medically the plant can be used to combat Staphylococcus aureus – a major and ubiquitous pathogen for humans. The significance of this study is thus that it will benefit and help the medical community and future research as the guide to sustainable production and utilization of Mentha longifolia L.
AFRIKAANSE OPSOMMING: Grondtekstuur, plant beskikbare water en kunsmis N sal plantegroei, biomassaproduksie en antimikrobiese-eienskappe van plaaslike medisinale plante affekteer. Die doel van die navorsing was om die effek van grondteksture, plant beskikbare water (PAW) en stikstof op die biomassaproduksie en antimikrobieseeienskappe van Mentha longifolia L. te bestudeer. 'n Tweerigting-faktoriaal-eksperiment is gebruik deur drie verskillende grondteksture (leem, sanderige-leemgrond en leemsand) en drie vlakke van PAW in die eerste geval (0%, 50% en 90% uitputting van PAW) en drie vlakke van N-kunsmistoedienings in die tweede geval. Die basiese kunsmis KNO3, K2SO4, KH2PO4, KClCa(NO3)2.2H2Oz, CaSO4.2H2O en MgSO4.7H2O is gebruik in so „n mate dat 0Kg ha-1, 150kg ha-1 en 250 kg ha-1 Nas sproeibemesting toegedien is. Dit is vier keer herhaal. Die eksperiment is uitgevoer in 'n tonnel. Die hoogstebiomassaproduksie is van die eerste geval verkry van 0% uitputting van PAW behandelings, terwyl 50% en 90% uitputting van PAW ooreenstem met mekaar op laer biomassaproduksies. In terme van grondtekstuur is 'n hoër biomassaproduksie verkry in leemsand gevolg deur leem en sanderigeleem. In die tweede geval is soortgelyke invloede van grondtekstuur duidelik en die beduidende biomassaproduksies was die hoogste, intermediêre en laagste van 250 kg ha-1, 150kg ha-1 en 0Kg ha-1 van kunsmis N, onderskeidelik. Gevolglik, Mentha longifolia L onthul 'n minimale bakteriese inhibisie aktiwiteit op 20g 100ml-1 teen Staphylococcus aureus (gram positiewebakterieë) onder Minimum inhiberende konsentrasie assay-vatbaarheidtoets. Die gevolgtrekking is dus dat grondtekstuu biomassaproduksie beïnvloed. In 'n soortgelykewyse, het PAW 'n beduidende impak op die totale biomassaproduksie. 'n Toename in N-kunsmis verhoog vegetatiewe biomassaproduksie. Plantmateriaalverkry van Mentha longifolia L het antimikrobiale-eienskappe en kan as Die medisinale plante gebruik word om Staphylococcus aureus te bestry - 'n groot en alomteenwoordige patogeen in die mens. Die belangrikste bydrae van die navorsing is die bydra wat dit tot die mediesegemeenskap gemaak het. Die studie het ook riglyne gestel vir toekomstige navorsing vir volhoubare produksie van Mentha longifolia L.
NRF and DST for the funding of this study through the Seboka Project
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CHIAZZESE, MURJAL. "Estimation of N2O and CO2 emissions from organic and N fertilizers by coupling field measurements with modelling analysis." Doctoral thesis, Università Cattolica del Sacro Cuore, 2015. http://hdl.handle.net/10280/6529.
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L'effetto dei gas serra sul cambiamento climatico ha portato molti esperti a considerare la riduzione delle emissioni di gas serra come strategia per il riscaldamento globale. In particolare tale fenomeno è causato dall’anidride carbonica (CO2), metano (CH4) e il protossido di azoto (N2O). E 'ampiamente accettato che la principale fonte antropica di gas a effetto serra (tranne CO2) è dovuta alle attività agricole. Lo scopo di questo studio è quello di definire concetti e strumenti per facilitare il settore agricolo a ridurre le emissioni di gas serra. In particolare, abbiamo posto la nostra attenzione ai sistemi di misurazione delle emissioni dal suolo, testando un nuovo sistema (SASSFlux) e le sue caratteristiche a confronto con due strumenti ampiamente utilizzati (Bruel & Kjaer e gascromatografia). Inoltre abbiamo testato due modelli di simulazione (DNDC e SPACSYS) valutando i dati simulati e quelli misurati su un esperimento effettuato su lisimetri. In fine abbiamo applicato le conoscenze acquisite in pieno campo per la valutazione delle emissioni di CO2 e N2O con diversi concimi e lavorazione del terreno. La tesi si propone di fornire una visione completa dei diversi aspetti da affrontare nella valutazione delle emissioni di gas serra provenienti da diversi scenari di gestione agricola.The effect of greenhouse gases (GHG) on climate change led many experts to consider the reduction of GHGs emissions as a crucial strategy to tackle the predicted global warming. In particular, atmospheric warming is caused mainly by carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). It is widely accepted that the main anthropogenic source of GHG (except CO2) is due to agriculture activities. The purpose of this study was to help define concepts and tools to facilitate agricultural sector to reduce greenhouse gas emissions. In particular we based our focus on measuring systems for CO2 emissions, testing the performance of novel system (SASSFlux) and its features in different condition with two widely used instruments (Bruel&Kjaer and gas chromatography). Moreover we testing two process-based models, DNDC and SPACSYS, evaluating their performance and the agreement between simulated and measured data on a experiment carried out on lysimeters. At the end we applied all the knowledge acquired on a field experiment evaluating CO2 and N2O emissions from different organic and mineral fertilizers and tillage. The complete thesis aims to provide a comprehensive view of the different aspects to be addressed in the assessment of GHG emissions from different scenarios of agricultural management.
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Ramos, Adriana. "Análise do desenvolvimento vegetativo e produtividade da palmeira pupunha (Bactris gasipaes Kunth) sob níveis de irrigação e adubação nitrogenada." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/11/11143/tde-04022003-163955/.
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O presente trabalho tem como objetivo avaliar o efeito da aplicação de lâminas de irrigação com níveis de adubação nitrogenada no desenvolvimento vegetativo, produtividade de palmito e na distribuição espacial do sistema radicular da pupunheira. O experimento foi conduzido dos 12 aos 34 meses após o plantio (abril/2000 a fevereiro/2002), período este que corresponde à fase de maior crescimento da cultura, no campo experimental de Irrigação e Drenagem, da Fazenda Areão da Escola Superior de Agricultura "Luiz de Queiroz" - ESALQ/USP, localizada no município de Piracicaba - S.P. à latitude de 22° 42'30"S e longitude de 47° 30'00"W. O delineamento empregado foi em blocos casualizados, com os tratamentos distribuídos em esquema fatorial 3 x 4. Os tratamentos referentes às lâminas de irrigação foram L1, L2, L3 e L4 equivalentes a 0, 50%, 100% e 120% da evapotranspiraçõo de referência determinada em função do Tanque Classe A. Os níveis de nitrogênio aplicados foram N1, N2 e N3 correspondentes a 0, 200 kg ha -1 ano -1 e 400 kg ha -1 ano -1 de N, aplicado sob a forma de nitrato de potássio, nitrato de cálcio e uréia. Foram realizadas fertirrigações semanais, pelo emprego de uma bomba injetora de diafragma. Já, as avaliações do desenvolvimento vegetativo foram feitas pelas medidas de algumas variáveis de crescimento e produtividade. A distribuição espacial do sistema radicular foi determinada pelos métodos: direto, com abertura de trincheiras e digitalização de imagens e indireto, em que a área potencial de absorção das raízes foi estimada em função da variação de umidade entre dias subseqüentes. Houve efeito significativo dos tratamentos (irrigação e adubação) para todos os parâmetros de crescimento e de produção de palmito, em grande parte dos períodos avaliados. Os tratamentos com déficit hídrico (L2) e sem irrigação (L1) apresentaram os menores crescimentos nos parâmetros avaliados acarretando uma redução de 18% a 27% na produção total de palmito. Apesar de não ter ocorrido diferenças estatísticas entre os tratamentos L3 e L4, os maiores crescimentos e produtividades foram obtidas em L3 (100% ETo). Para nitrogênio, N2 e N3 também não diferiram estatisticamente entre si, entretanto, maiores respostas foram obtidas em N2 (200 kg ha -1 ano -1 ). Portanto, levando-se em conta o crescimento da planta e os custos de aplicação de lâminas e fertilizantes, os resultados indicam que a irrigação com 100% ETo e adubação com 200 kg de N ha -1 ano -1 são as recomendadas para a pupunheira cultivada em condições agroclimatológicas semelhantes à região do presente estudo. As regressões para as lâminas de irrigação apresentaram efeitos lineares significativos para todas as variáveis analisadas, com exceção do número de perfilhos, vindo confirmar o alto consumo de água da cultura e a importância da irrigação quando cultivada em áreas com déficit hídrico. Para o nitrogênio, com exceção dos parâmetros relacionados à produção de palmito, todos os demais apresentaram efeitos lineares das regressões, ressaltando a importância do nitrogênio no desenvolvimento vegetativo da pupunheira. Todos os tratamentos (lâminas) aplicados resultaram em uma distribuição radicular (área e comprimento) bastante superficial, variando de 97,8%, 92%, 86,7% e 97,8% de raízes distribuídas até a profundidade de 0,40 m.Peach palm (Bactris gasipaes Kunth) plants were subjected to different irrigation and N fertilizer treatments in an experiment field conducted at the Irrigation and Drainage Area (22° 42'30"S and 47° 30"00"W) of Areão Agricultural Experiment Area, ESALQ/USP, Piracicaba, SP, Brazil. The principal aim was to study the growth, development and yield of peach palm in the first plant yield cycle (April 2000 to February 2002), and also the spatial distribution of the root system. The irrigation (0%, 50%, 100% and 120% of ETo) and N fertilizer (0kg.ha -1 .year -1 , 200kg.ha -1 .year -1 and 400kg.ha -1 .year -1 ) treatments were grouped in randomized blocks resulting in a 3x4 factorial experiment. The water and N were applied through the use of a diaphragm-activated injection pump in a weekly basis. Plant parameters (as LAI obtained by the use of LAI 2000) were measured monthly to accompany the plant growth and development and the spatial distribution of the root system was evaluated by the use of a direct method (measuring by image analysis of the length and area of roots exposed by digging a soil-trench within the crop) and an indirect one (recording the moisture level differences between subsequent days). Significative differences among treatments were found in almost the total duration of the experiment. The water deficit treatments (0% and 50% of ETo) showed the lowest values of all parameters resulting in yield losses of 18% to 27%. On the other hand, the 100% of ETo treatment exhibited the highest ones, although the 120% of ETo treatment did not differ statistically from the former. Also, the 200kgN.ha -1 .year -1 and 400kgN.ha -1 .year -1 treatments did not differ statistically, showing the 200kgN.ha -1 .year -1 treatment the highest values. All parameters except offshoot number increased linearly with increasing water and except yield with increasing N. The root system in all treatments concentrated in the shallow layers of the soil with 97,8%, 92%, 86,7% and 97,8% of roots distributed until 40 cm depth.
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Casarini, Edivaldo. "Doses de N e K aplicados via fertirrigação na cultura da roseira (Rosa sp.) em ambiente protegido." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/11/11143/tde-16122004-163854/.
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A fertirrigação em rosas é uma técnica bastante utilizada pelos produtores de flores. O nitrogênio e o potássio são os nutrientes mais exigidos nas distintas fases da cultura, onde a aplicação de quantidades corretas aumenta a produtividade e a qualidade das flores. Com o objetivo foi avaliar a produtividade e a qualidade das hastes florais na cultura da roseira, cultivar Versilha, em ambiente protegido conduziu-se um experimento na área experimental do Departamento de Engenharia Rural da ESALQ/USP, localizado no município de Piracicaba, SP, entre os meses de novembro/2002 a setembro/2003. Os tratamentos foram dispostos numa combinação de 4 doses de N (10; 20; 30 e 40 g.pl-1.ano-1), 4 doses de K (10; 20; 30 e 40 g.pl-1.ano-1). O delineamento experimental adotado foi o de blocos casualizados com 3 repetições, sendo os fatores arranjados em esquema fatorial 4 x 4. O sistema de irrigação utilizado foi o gotejamento, adotando manejo de irrigação com tensiômetros e tanque evaporimétrico reduzido. Foram avaliados os parâmetros qualitativos das hastes e botões de rosas, a produtividade, a condutividade elétrica e os níveis de NO3- e K+ na solução do solo através de medidor de íons (HORIBA) e as concentrações de macro e micronutrientes nas folhas. A lâmina total aplicada entre os meses de fevereiro e setembro foi de 839,43 mm com média de 3,46 mm.dia-1 e o potencial matricial médio da água no solo foi de 10 kPa na camada de 0 20 cm. A produtividade de rosas nas duas colheitas reduziu linearmente com as doses de K aplicadas. Para a qualidade das hastes não houve diferença significativa para a maioria dos parâmetros avaliados nas duas colheitas. A condutividade elétrica e as concentrações de NO3- e K+ na solução do solo aumentaram linearmente de acordo com as doses de N e K aplicados. Para as concentrações de N e P nas folhas observou-se a influência das doses de N, para Ca2+ e Mg2+ observou-se a influencia das doses de K, mostrando o antagonismo entre eles. Nas concentrações de micronutrientes, o boro foi influenciado pelo N e K e as concentrações de Fe2+ e Mn2+ foram influenciadas pelo N.The rose plant fertigation is a technique quite useful by flowers growers. The nitrogen and the potassium are the most required nutrients in the distinct crop phases, where the application of correct amounts increases the yield and flower quality. A study was carried out under protected environment conditions, at the experimental area of the Department of Rural Engineering of Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, São Paulo State, Brazil, from November/2002 to September/2003. The aim of the experiment was to evaluate the yield and quality of rose flowers, Versilha cultivar. The treatments were disposed in combination of 4 N levels (10; 20; 30 and 40 g.pl-1.year-1) and 4 K levels (10; 20; 30 and 40 g.pl-1.year-1). The statistical test was performed in randomized blocks, with 3 replications, arranged in a 4 x 4 factorial design. Drip system irrigation was used with tensiometers and a reduced evaporation pan in order to manage water depth. The parameters evaluated were: stem and bud quality, yield, electric conductivity, NO3- and K+ soil solution levels by ion meter (HORIBA) and concentrations of macro and micronutrients in the leaves. Total irrigation water depth applied between February and September was 839,43 mm with an average of 3,46 mm.d-1 and the average soil matric potencial was -10 kPa in a 0 20 cm in depth. The two flushes rose yield was linearly reduced with the applied K levels. Stems quality showed no difference for majors evaluated parameters. The electric conductivity, NO3- and K+ soil solution levels linearly increased according to the levels of N and K. The N and P concentrations in the leaves were influenced by N levels. Ca2+ and Mg2+ concentrations in the leaves were influenced by K levels, showing antagonism between them. In micronutrients concentrations, boron showed an interaction, influenced by N and K levels and Fe2+ and Mn2+ influenced by N levels.
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Alves, Ana Carolina. "Métodos para quantificar a volatilização de N-NH3 em solo fertilizado com uréia." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/74/74131/tde-20102006-143501/.
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As perdas gasosas nitrogenadas são consideráveis em pastagens e a utilização de métodos simples e acessíveis para mensurá-las é de extrema necessidade na avaliação do ciclo de N nesses sistemas. O objetivo desse trabalho foi determinar métodos para quantificar o NH3 volatilizado de fertilizantes nitrogenados aplicados ao solo, que tenham pouca interferência nos processos de volatilização. Foram conduzidos dois experimentos em casa de vegetação pertencente ao Departamento de Zootecnia da Faculdade de Zootecnia e Engenharia de Alimentos. O delineamento experimental utilizado foi inteiramente casualizado com cinco repetições. No primeiro experimento os tratamentos foram: absorvedor de espuma a 1, 10, 20 e 30 cm do solo; absorvedor de papel a 1, 10, 20 e 30 cm do solo; coletor semi-aberto estático; e balanço de 15N (método de referência). E no segundo experimento os tratamentos foram: absorvedor de espuma a 1, 5, 10 e 20 cm do solo; absorvedor de papel a 1, 5, 10 e 20 cm do solo; absorvedor com ácido a 1, 5 e 10 cm do solo; coletor semi-aberto estático; e balanço de 15N (método de referência). Nos dois experimentos quantificou-se o N (NH3) volatilizado. As perdas de N-NH3 determinadas pelo método do balanço de 15N, no experimento 1, foram elevadas (73% do N aplicado) e nenhum dos absorvedores avaliados apresentou volatilização de N-NH3 igual ao balanço de 15N. Isso provavelmente ocorreu devido ao elevado valor de pH do solo e a intensa corrente de ar formada pelos exaustores da casa de vegetação, o que contribuiu para o aumento da volatilização de N-NH3 e prejudicou a sua captação pelos absorvedores. No experimento 2, o coletor semi-aberto, o absorvedor de espuma a 1cm, os absorvedores de papel a 1 e 5 cm e os absorvedores com ácido a 1; 5 e 10 cm apresentaram valores acumulados de N-NH3 volatilizado iguais ao balanço de 15N, estimando portanto as reais perdas acumuladas de N-NH3 (p<0,0001). O absorvedor de espuma a 1 cm foi o que apresentou a curva de perdas de N-NH3 mais semelhante a do coletor semi-aberto, que foi considerado o método de referência para as comparações de perdas de N-NH3 a cada dois dias durante o período experimental.Gaseous losses are considerable in pastures, therefore the utilization of simple and accessible methods to measure them are extremely necessary to evaluate the cycle of N in these systems. This work aimed to determine methods that quantify volatilized NH3 of nitrogenous fertilizers applied to soil which have little interferente in the volatilization processes. Two experiments in a greenhouse from Departamento de Zootecnia of Faculdade de Zootecnia e Engenharia de Alimentos were conducted. Completely randomized experimental design was used with five repetitions. Treatments from the first experiment were: foam absorber at 1, 10, 20 and 30 cm from the ground; paper absorber at 1, 10, 20 and 30 cm from the ground; static semi-open collector and 15N balance (reference method). In the second experiment the treatments used were as follows: foam absorber at 1, 5, 10 and 20 cm from the ground; paper absorber at 1, 5, 10 and 20 cm from the ground; acid absorber at 1, 5 and 10 cm from the ground; static semi-open collector and 15N balance (reference method). Both experiments quantified volatilized N NH3. N-NH3 losses determined by 15N balance method in experiment 1 were high (73% of the applied N) and none of the evaluated absorbers presented the same N-NH3 volatilization as the 15N balance. These results probably occurred due to the high pH value from the soil and the intense airflow generated by the greenhouse fans what allowed the increase of N-NH3 volatilization and harmed its capitation by the absorbers. In experiment 2, semi-open collector, foam absorber at 1cm, paper absorbers at 1 and 5 cm and acid absorbers at 1; 5 and 10 cm presented equal accumulated values of volatilized N-NH3 as 15N balance, therefore estimating the real N-NH3 accumulated losses (p<0,0001). Foam absorber at 1cm presented curves of N-NH3 losses similar to semi-open collector, considered the reference method to compare N-NH3 losses on each two days during the experimental period.
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Chen, Zhengqi 1959. "Soybean (Glycine max L. Merrill) nodulation, growth and grain yield as influenced by N fertilizer, population density and cultivar in southern Quebec." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59528.
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Soybean growth with respect to N fertilizer rates, plant population densities and two cultivars was investigated on three Quebec soils at four sites. Soybean nodulation, growth, grain yields and nutrient uptake at three developmental stages were investigated. Soil nitrate levels after harvest were also studied.N fertilizer application depressed soybean nodulation consistently, but improved soybean growth where initial soil nitrate levels were low. Grain yield was increased at one site with added N, where soybean growth was stressed by low initial soil nitrate levels (below 17 kg N/ha) and severe summer drought. Soybean N and K uptake were increased with increased N fertilizer but P uptake was not affected. Residual soil nitrate content in the 0-50 cm depth in the fall of the crop year increased linearly and this effect carried over to the following spring.
Plant population had little effect on individual plant nodulation but increased fresh nodule mass per unit area. Plant biomass, grain yield and nutrient uptake were increased with increased population densities.
The cultivar Apache had better nodulation potential and grain yield potential and was better adapted to intensive management practices with high plant populations than the cultivar Maple-Arrow.
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Silva, Ramon de Souza Victorino da. "Uso de imagens multiespectrais de baixo custo para classificar n?veis de N aplicados ao solo em Agricultura de Precis?o." Universidade Federal Rural do Rio de Janeiro, 2016. https://tede.ufrrj.br/jspui/handle/jspui/2198.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior, CAPES, Brasil.
The aim of this project was to develop a statistical classifier based on algorithms using Bayesian theorem for prediction of nitrogen applied to the soil using low cost multispectral images Tifton85 pastures From information obtained from these images the indexes were calculated spectrum, which was used in a feature vector for discriminating N levels applied to the soil. The research was developed in the Rural Federal University of Rio de Janeiro, Department of Engineering, Machinery Area and Energy in Agriculture. The data were obtained from an experiment installed in the production area of Company Feno Rio Agro LTDA, partner in the project. Images were acquired in 2 times one after 36 days due to the cutting standardization of culture using a UAV (Unmanned Aerial Vehicle) and at 7, 14, 21, 28, 35, 42, 56 days using an imaging platform an experiment with 6 portions 250m2 (10x25m) containing respectively the treatments (0, 50, 100, 150, 200 and 250 kg ha-? N), statistical analyzes were performed the computer program SAS version student using PROCDISCRIM procedure. It was determined discriminant functions for each dose of nitrogen, using as feature vectors vegetation indices (NDVI, GNIR, SAVI, GNDVI, RNIR). These discriminant functions were tested in a Bayesian classifier, and the highest accuracies were using vegetation indices together getting a Kappa coefficient and overall accuracy of 83% and 80%, respectively. The results indicate that low cost multispectral images can be used to develop classifiers of nitrogen applied to the soil. These binders may be applied in computational algorithms in agricultural machinery control systems for fertilizer application at variable rates in precision agriculture.
O objetivo geral deste projeto foi desenvolver um classificador estat?stico com base em algoritmos utilizando o teorema bayesianos para predi??o de doses de nitrog?nio aplicadas ao solo, atrav?s de imagens multiespectrais de baixo custo em pastagens de Tifton85 A partir de informa??es obtidas nessas imagens foram calculados os ?ndices espectrais, os quais foram utilizados em um vetor de caracter?sticas para discriminar n?veis de N aplicados ao solo. A pesquisa foi desenvolvida na Universidade Federal Rural do Rio de Janeiro, Departamento de Engenharia, ?rea de M?quinas e Energia na Agricultura. Os dados foram obtidos de um experimento instalado no campo de produ??o da Empresa Feno Rio Agro LTDA, parceira do projeto. As imagens foram adquiridas em 2 momentos uma ap?s 36 dias decorrentes ao corte de uniformiza??o da cultura utilizando um VANT (Ve?culo A?reo N?o Tripulado) e aos 7, 14, 21, 28, 35, 42, 56 dias utilizando uma plataforma de capta??o de imagens de um experimento com 6 parcelas contendo respectivamente os tratamentos (0, 50, 100, 150, 200 e 250 kg ha -? de N), as an?lises estat?sticas foram realizadas no programa computacional SAS vers?o estudante, utilizando o procedimento PROCDISCRIM. Determinou-se fun??es discriminantes para cada dose de nitrog?nio, utilizando-se como vetores de caracter?sticas os ?ndices de vegeta??o (NDVI, GNIR, SAVI, GNDVI, RNIR). Essas fun??es discriminantes foram testadas em um classificador bayesiano, sendo que a maior acur?cia de classifica??o foi utilizando os ?ndices de vegeta??o em conjunto obtendo um coeficiente Kappa e a exatid?o global de 83% e 80%, respectivamente. Os resultados indicam que imagens multiespectrais de baixo custo podem ser utilizadas para desenvolver classificadores de doses de nitrog?nio aplicadas ao solo. Esses classificadores poder?o ser aplicados em algoritmos computacionais em sistemas de controle de m?quinas agr?colas para aplica??o de fertilizantes a taxas vari?veis em agricultura de precis?o.
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Sylvestre, Thiago de Barros [UNESP]. "Mineralização de nitrogênio do esterco bovino e produção de alface em função de N-ureia." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/123768.
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000821942.pdf: 565858 bytes, checksum: b886e5fbaf6278d0c7b52aa30a41644e (MD5)Foram conduzidos quatro experimentos, um no laboratório e três no campo, com os objetivos de: comparar métodos de determinação da mineralização de N de esterco bovino em laboratório e em campo; avaliar a produtividade de alface e o acúmulo de nitrato nas plantas, em função de doses de N-ureia no plantio e em cobertura. O solo utilizado no experimento em laboratório foi coletado no local dos experimentos em campo e é um Latossolo Vermelho. No ensaio em laboratório foi feita incubação de solo mais esterco (0, 5, 10, 20, 40 e 80 t ha-1), a 28oC, por até 180 dias, com avaliação periódica da quantidade de N mineralizado (N-NH4 + + N-NO3 -). Em campo, de novembro de 2011 a maio de 2012, foi conduzido experimento com sacos de polietileno enterrados em canteiros, a 10 cm de profundidade, com as mesmas doses de esterco e os mesmos tempos de avaliação usados no laboratório. Simultaneamente, em campo, foi conduzido experimento com alface, empregando as mesmas doses de esterco, para obter o N absorvido em 180 dias (três cultivos sucessivos). No ano seguinte, nos meses de novembro e dezembro, foi conduzido experimento em campo, combinando duas doses de adubo nitrogenado no transplantio (0 e 40 kg ha-1 de N-ureia) e quatro em cobertura (0, 30, 60 e 90 kg ha-1), parceladas em duas ou três vezes (fatorial 2x4x2). Neste experimento, a dose de esterco aplicada foi calculada com base na taxa de mineralização determinada com o método dos sacos enterrados. Os métodos de incubação em laboratório e em campo não foram eficientes para predizer a disponibilidade de N para alface em solo adubado com esterco bovino. A aplicação de 40 kg ha-1 de N-ureia no transplantio das mudas resultou em aumento de produtividade de 26% (3.583 kg ha-1) e 98% da produtividade máxima foi obtida com 60 kg ha-1 de N em cobertura, parcelados em duas aplicações. O teor de nitrato nas plantas ficou abaixo do limite tolerado em todas as combinações ...
An experiment in laboratory and three in the field were carried out with the objectives of compare laboratory and field methods to determine N mineralization rate of cattle manure; assess lettuce productivity and nitrate accumulation in plants, due to urea-N rates at planting and topdressing. The soil used in the laboratory experiment was collected at the site of field experiments and is an Oxisol. In the laboratory method, soil and manure (0, 5, 10, 20, 40 and 80 t ha-1) were incubated at 28ºC for 180 days, and the amount of N mineralized (NH4 +-N + NO3 --N) was determined periodically. Field experiment was carried out in polyethylene buried bags in beds, in 0.1 m deep, with the same doses of manure and the same evaluation times used in the laboratory, from November 2011 until May 2012. Simultaneously, a field experiment was carried out with lettuce, using the same doses of manure to get N uptake in 180 days (three successive crops). In the following year, in November and December, it was carried out an experiment combining two doses of nitrogen fertilizer at transplanting (0 and 40 kg ha-1 urea-N) and four in topdressing (0, 30, 60 and 90 kg ha-1), divided into two or three application times (2x4x2 factorial). In this experiment, the dose of manure was calculated based on the rate determined by buried bags method. The methods of incubation in the laboratory and in the field were not efficient for predicting N availability to lettuce in soil fertilized with cattle manure. The application of 40 kg ha-1 urea-N at transplantation resulted in increased productivity by 26% (3,583 kg ha-1) and 98% of maximum productivity was obtained with 60 kg ha-1 N, splitted in two applications. The nitrate content in plants was below the limit tolerated at all dose combinations at planting and topdressing
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Francisco, Agostinho Domingos Miguel. "Eficiência de fontes de nitrogênio e enxofre na composição químico-bromatológica e algumas características agronômicas da cultura de milho (Zea mays L.) em sistema de plantio direto." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/74/74131/tde-19022009-143157/.
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O presente trabalho foi desenvolvido no Departamento de Zootecnia da Faculdade de Zootecnia e Engenharia de Alimentos da Universidade de São Paulo FZEA/USP localizada em Pirassununga-SP no período de 16/12/2006 a 10/05/2007 em condições de campo com o cultivo do híbrido do milho super precoce GNZ-2005 em Latossolo Vermelho Amarelo distrófico férrico. O experimento teve como objetivo avaliar a eficiência de fertilizante nitrogenado FASN (Fusion Amonium Sulfate Nitrate) comparado na composição químico-bromatológica e algumas características agronomicas da cultura de milho (Zea mays L.) à fontes tradicionais de nitrogênio como nitrato de amônio, uréia e sulfato de amônio, implantado no sistema plantio direto. Foram avaliadas as perdas de nitrogênio por volatilização da amônia, os atributos químicos e físicos do solo, rendimento de grãos (kg ha-1), matéria seca total (%) e análise bromatológica e foliar. A dose de nitrogênio foi 100 kg ha-1 de N em todos os tratamentos, exceto nas testemunhas (T1 e T2), que também receberam 450 kg ha-1 de 8:28:16 + 0,5% de Zn. O delineamento experimental foi em blocos completos casualizados, com dez tratamentos e quatro repetições. Os tratamentos foram: T1: Testemunha +Gesso (-N+S), T2: Testemunha absoluta (-N-S), T3: Uréia - 45% N, T4: Uréia + Gesso 14%S, T5: Uréia + sulfato de amônio - 21%N /24%S-(33:00:00+12%S), T6: Nitrato de amônio - 30%N, T7: Nitrato de amônio - 30%N + gesso, T8: Nitrato de amônio + Sulfato de Amônio - 21% N/ 24%S - (27,8:00:00+6%S), T9: Sulfato de amônio, T10: FASN 26%N/14%S. Perdas por volatilização de amônia foram avaliadas em todos os tratamentos de T1 a T10 por meio de coletores semi-abertos estáticos colocados em cada parcela em que se estudou a volatilização. Foram colocadas cinco bases para cada coletor, onde se aplicou as fontes nitrogenadas na dose de 100 kg ha-1 de N. O N-NH3 volatilizado foi retido em espumas embebidas em solução ácida e extraída com solução ácido clorídrico para posterior quantificação das perdas. A avaliação do estado nutricional das plantas, de atributos químicos e físicos do solo, volatilização de amônia, características bromatológicas e a produtividade foram efetuadas em todos os tratamentos. A avaliação do estado nutricional foi feita pela análise química dos teores de nutrientes nas folhas coletadas no florescimento. Atributos químicos do solo foram avaliados por meio de análises laboratoriais de amostras coletadas nas camadas de 0 a 20 e de 20 a 40 cm de profundidade, após a colheita do milho. Dentre das fontes nitrogenadas avaliadas, a uréia implicou em maiores perdas de nitrogênio N-NH3 aos seis dias após aplicação. Com relação ao desempenho geral das fontes de nitrogênio, pode-se constatar que o FASN teve comportamento similar ao do sulfato de amônio e do nitrato de amônio.O presente trabalho foi desenvolvido no Departamento de Zootecnia da Faculdade de Zootecnia e Engenharia de Alimentos da Universidade de São Paulo FZEA/USP localizada em Pirassununga-SP no período de 16/12/2006 a 10/05/2007 em condições de campo com o cultivo do híbrido do milho super precoce GNZ-2005 em Latossolo Vermelho Amarelo distrófico férrico. O experimento teve como objetivo avaliar a eficiência de fertilizante nitrogenado FASN (Fusion Amonium Sulfate Nitrate) comparado na composição químico-bromatológica e algumas características agronomicas da cultura de milho (Zea mays L.) à fontes tradicionais de nitrogênio como nitrato de amônio, uréia e sulfato de amônio, implantado no sistema plantio direto. Foram avaliadas as perdas de nitrogênio por volatilização da amônia, os atributos químicos e físicos do solo, rendimento de grãos (kg ha-1), matéria seca total (%) e análise bromatológica e foliar. A dose de nitrogênio foi 100 kg ha-1 de N em todos os tratamentos, exceto nas testemunhas (T1 e T2), que também receberam 450 kg ha-1 de 8:28:16 + 0,5% de Zn. O delineamento experimental foi em blocos completos casualizados, com dez tratamentos e quatro repetições. Os tratamentos foram: T1: Testemunha +Gesso (-N+S), T2: Testemunha absoluta (-N-S), T3: Uréia - 45% N, T4: Uréia + Gesso 14%S, T5: Uréia + sulfato de amônio - 21%N /24%S-(33:00:00+12%S), T6: Nitrato de amônio - 30%N, T7: Nitrato de amônio - 30%N + gesso, T8: Nitrato de amônio + Sulfato de Amônio - 21% N/ 24%S - (27,8:00:00+6%S), T9: Sulfato de amônio, T10: FASN 26%N/14%S. Perdas por volatilização de amônia foram avaliadas em todos os tratamentos de T1 a T10 por meio de coletores semi-abertos estáticos colocados em cada parcela em que se estudou a volatilização. Foram colocadas cinco bases para cada coletor, onde se aplicou as fontes nitrogenadas na dose de 100 kg ha-1 de N. O N-NH3 volatilizado foi retido em espumas embebidas em solução ácida e extraída com solução ácido clorídrico para posterior quantificação das perdas. A avaliação do estado nutricional das plantas, de atributos químicos e físicos do solo, volatilização de amônia, características bromatológicas e a produtividade foram efetuadas em todos os tratamentos. A avaliação do estado nutricional foi feita pela análise química dos teores de nutrientes nas folhas coletadas no florescimento. Atributos químicos do solo foram avaliados por meio de análises laboratoriais de amostras coletadas nas camadas de 0 a 20 e de 20 a 40 cm de profundidade, após a colheita do milho. Dentre das fontes nitrogenadas avaliadas, a uréia implicou em maiores perdas de nitrogênio N-NH3 aos seis dias após aplicação. Com relação ao desempenho geral das fontes de nitrogênio, pode-se constatar que o FASN teve comportamento similar ao do sulfato de amônio e do nitrato de amônio.
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Ortas, Ibrahim. "The effect of different forms and rates of nitrogen (NH4+-N and NO3-N) and different rates of phosphorous fertilizer on rhizosphere pH and P uptake in mycorrhizal and non-mycorrhizal sorghum plants." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239531.
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Bergamasco, Marina Ali Mere [UNESP]. "Formas de N-orgânico em latossolo em função de nitrogênio e de plantas de cobertura em pré-safra do milho." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/135970.
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000858351.pdf: 977824 bytes, checksum: 0490833070f6229ca597b6361902c86d (MD5)O manejo do solo em sistema plantio direto combinando plantas de cobertura e doses de nitrogênio pode interferir nas formas e na disponibilidade de N. Ter um índice químico sensível para detectar variações na disponibilidade de N causadas pelo manejo pode aumentar a precisão das recomendações. Pretendeu-se com este trabalho: avaliar os efeitos de plantas de cobertura em pré-safra de milho, e de doses de N em cobertura no milho, nas formas de N orgânico do solo, em experimento de longa duração; associar formas de N orgânico com disponibilidade, por meio de correlação com o N determinado por destilação a vapor direta. O experimento está instalado em Latossolo Vermelho argiloso, em blocos ao acaso com parcelas subdivididas, sendo as plantas de cobertura os tratamentos principais e as doses de N os tratamentos secundários. As plantas de cobertura são mucuna-cinza, crotalária, feijão-de-porco, lablab, milheto e vegetação espontânea e as doses de N-ureia em cobertura no milho são 0 e 120 kg ha-1. A amostragem de solo foi feita no décimo segundo ano do experimento, nas camadas de 0-5; 5-10; 10-20; 20-40; 40-60 cm de profundidade, 30 dias após a dessecação das plantas de cobertura. As amostras foram submetidas à hidrólise ácida e as formas do N orgânico determinadas no fracionamento foram: N-total hidrolisável, N-NH4+ hidrolisável, N-aminoácidos, N-NH4+ hidrolisável + N-aminoaçúcares e N-insolúvel em ácido. Por diferença foram obtidos os teores de N-não identificado (N-total hidrolisável - N-NH4+ hidrolisável + N-aminoaçúcares + N-aminoácidos) e de N-aminoaçúcares (N-NH4+ hidrolisável + N-aminoaçúcares - N-NH4+ hidrolisável). A fração N-aminoaçúcares predominou em relação às outras formas de N-hidrolisável e o cultivo de plantas de cobertura não teve efeito claro na definição desse predomínio. A adubação nitrogenada diminuiu os teores de N das frações mais lábeis...
The soil management in no-tillage system with cover crops and nitrogen levels changes the forms and the availability of N. A sensitive chemical index to detect variations in the availability of N caused by management can increase the accuracy of the fertilizer recommendations. With this work it was intended to evaluate the effects of cover crops in maize pre-cropping, and levels of N sidedress fertilization in maize, in the forms of soil organic N in a long-term experiment; to associate organic N forms with availability, through the correlation with N determined by direct steam distillation. The experiment is installed in a sandy clay Oxisol, in randomized blocks with split plots, with cover crops as main treatments and doses of N as secondary treatments. The cover crops are gray velvet bean, sunn hemp, jack bean, lablab, millet and spontaneous vegetation. The levels of urea-N sidedress fertilization in corn are 0 and 120 kg ha-1. The soil samples were collected in the twelfth year of the experiment, at the layers 0-5; 5-10; 10-20; 20-40; 40-60 cm, 30 days after the desiccation of cover crops. The samples were submitted to acid hydrolysis followed by the determination of: total hydrolysable N, hydrolysable NH4+-N, amino acids-N, amino sugars-N and acid insoluble-N. By subtraction were obtained unidentified-N (total hydrolysable-N - hydrolysable NH4+ + amino sugars + amino acids) and amino sugars-N (hydrolysable NH4+ + amino sugars - hydrolysable NH4+) .The amino sugars-N predominated over other hydrolysable-N fractions and cover crops had no clear effect on the definition of that dominance. Nitrogen fertilization decreased the N levels of the most labile fractions (hydrolysable NH4+ and amino sugars-N). There was a correlation between N determined by direct steam distillation and organic-N forms, particularly amino acids-N and amino sugars-N, which defined these fractions as organic N pools that controls the N availability
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Sylvestre, Thiago de Barros. "Mineralização de nitrogênio do esterco bovino e produção de alface em função de N-ureia /." Jaboticabal, 2013. http://hdl.handle.net/11449/123768.
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Orientador: Mara Cristina Pessôa da CruzBanca: Manoel Evaristo Ferreira
Banca: Arthur Bernardes Cecílio Filho
Banca: José Ricardo Mantovani
Banca: Hamilton César de Oliveira Charlo
Resumo: Foram conduzidos quatro experimentos, um no laboratório e três no campo, com os objetivos de: comparar métodos de determinação da mineralização de N de esterco bovino em laboratório e em campo; avaliar a produtividade de alface e o acúmulo de nitrato nas plantas, em função de doses de N-ureia no plantio e em cobertura. O solo utilizado no experimento em laboratório foi coletado no local dos experimentos em campo e é um Latossolo Vermelho. No ensaio em laboratório foi feita incubação de solo mais esterco (0, 5, 10, 20, 40 e 80 t ha-1), a 28oC, por até 180 dias, com avaliação periódica da quantidade de N mineralizado (N-NH4 + + N-NO3 -). Em campo, de novembro de 2011 a maio de 2012, foi conduzido experimento com sacos de polietileno enterrados em canteiros, a 10 cm de profundidade, com as mesmas doses de esterco e os mesmos tempos de avaliação usados no laboratório. Simultaneamente, em campo, foi conduzido experimento com alface, empregando as mesmas doses de esterco, para obter o N absorvido em 180 dias (três cultivos sucessivos). No ano seguinte, nos meses de novembro e dezembro, foi conduzido experimento em campo, combinando duas doses de adubo nitrogenado no transplantio (0 e 40 kg ha-1 de N-ureia) e quatro em cobertura (0, 30, 60 e 90 kg ha-1), parceladas em duas ou três vezes (fatorial 2x4x2). Neste experimento, a dose de esterco aplicada foi calculada com base na taxa de mineralização determinada com o método dos sacos enterrados. Os métodos de incubação em laboratório e em campo não foram eficientes para predizer a disponibilidade de N para alface em solo adubado com esterco bovino. A aplicação de 40 kg ha-1 de N-ureia no transplantio das mudas resultou em aumento de produtividade de 26% (3.583 kg ha-1) e 98% da produtividade máxima foi obtida com 60 kg ha-1 de N em cobertura, parcelados em duas aplicações. O teor de nitrato nas plantas ficou abaixo do limite tolerado em todas as combinações ...
Abstract: An experiment in laboratory and three in the field were carried out with the objectives of compare laboratory and field methods to determine N mineralization rate of cattle manure; assess lettuce productivity and nitrate accumulation in plants, due to urea-N rates at planting and topdressing. The soil used in the laboratory experiment was collected at the site of field experiments and is an Oxisol. In the laboratory method, soil and manure (0, 5, 10, 20, 40 and 80 t ha-1) were incubated at 28ºC for 180 days, and the amount of N mineralized (NH4 +-N + NO3 --N) was determined periodically. Field experiment was carried out in polyethylene buried bags in beds, in 0.1 m deep, with the same doses of manure and the same evaluation times used in the laboratory, from November 2011 until May 2012. Simultaneously, a field experiment was carried out with lettuce, using the same doses of manure to get N uptake in 180 days (three successive crops). In the following year, in November and December, it was carried out an experiment combining two doses of nitrogen fertilizer at transplanting (0 and 40 kg ha-1 urea-N) and four in topdressing (0, 30, 60 and 90 kg ha-1), divided into two or three application times (2x4x2 factorial). In this experiment, the dose of manure was calculated based on the rate determined by buried bags method. The methods of incubation in the laboratory and in the field were not efficient for predicting N availability to lettuce in soil fertilized with cattle manure. The application of 40 kg ha-1 urea-N at transplantation resulted in increased productivity by 26% (3,583 kg ha-1) and 98% of maximum productivity was obtained with 60 kg ha-1 N, splitted in two applications. The nitrate content in plants was below the limit tolerated at all dose combinations at planting and topdressing
Doutor
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Lasbleiz, Marine. "Cycles biogéochimiques (Si, C, N, P) en lien avec la dynamique nutritionnelle du phytoplancton dans la région naturellement fertilisée des Kerguelen." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4092.
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Les cycles biogéochimiques du carbone et des éléments biogènes (Si, N, P) ont été étudiés en lien avec la dynamique nutritionnelle du phytoplancton dans le système naturellement fertilisé des Kerguelen. Cette étude s'inscrit dans le programme KEOPS2, qui a ciblé le nord-est du plateau des Kerguelen au début de la saison productive. La comparaison avec une zone HNLC limitée en fer a confirmé certaines des précédentes observations réalisées au cours des expériences de fertilisations artificielles et naturelles : le fer stimule clairement la croissance du phytoplancton et plus particulièrement celle des diatomées. Les zones naturellement fertilisées se sont en effet caractérisées par des biomasses en chlorophylle a et en silice biogénique 3-10 fois supérieures à la zone non-fertilisée et, par de fortes vitesses de production de silice biogénique atteignant des valeurs rarement observées dans l'océan Austral. La zone HNLC s'est caractérisée quant à elle par une population nanoplanctonique principalement composée de nanoflagellés autotrophes non siliceux. Ces travaux soulignent l'importance d'étudier la composition spécifique des populations de diatomées pour comprendre leurs implications dans les cycles du C et du Si. Nos observations ont montré que les caractéristiques physiologiques des diatomées conditionnent directement l'export de matière en profondeur dans la région des Kerguelen. Cette idée a notamment été illustrée par l'étude de l'évolution saisonnière du bloom au sud-est du plateauBiogeochemical cycles of carbon, silicon, nitrogen and phosphorus were studied in relation to the nutritional dynamics of phytoplankton in the naturally iron-fertilized region of Kerguelen, in the Southern Ocean. This study was conducted in the framework of the KEOPS 2 program which took place in the northeastern part of the Kerguelen Plateau in early austral spring (October-November 2011). The comparison between this iron-fertilized region and an iron-limited HNLC (High Nutrient Low Chlorophyll) area confirmed some previous observations from artificial and natural fertilization experiments: iron availability clearly stimulates phytoplankton growth and especially diatom growth. Iron-fertilized regions were characterized by 3-10 fold higher chlorophyll a and biogenic silica biomasses than the iron-limited area, as well as higher biogenic silica production rates reaching values rarely observed in the Southern Ocean. The HNLC area was characterized by a nanoplanktonic assemblage mainly composed of non-siliceous autotrophic nanoflagellates. Our results highlight the importance of studying the specific composition of diatom assemblages to better understand their impact on the C and Si biogeochemical cycles. Our observations showed that physiological traits of diatoms directly drove matter export to depth in the Kerguelen region. This idea was illustrated through the seasonal evolution of the south-eastern bloom by combining our data with KEOPS 1 data. In this region, a shift in the diatom assemblage was observed in parallel to an evolution of the vertical flux of matter, and of uptake and particulate matter ratios Si:C:N
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Merchán, Paniagua Sara. "Use of slow-release N fertilizer to control nitrogen losses due to spatial and climatic differences in soil moisture conditions and drainage in claypan soils." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4631.
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Thesis (M.S.) University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 24, 2007) Includes bibliographical references.
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Souza, Juscelio Ramos. "Adubação nitrogenada e perdas de N-NH3 de fontes convencionais e de eficiência aumentada na cultura do milho /." Jaboticabal, 2018. http://hdl.handle.net/11449/180226.
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Orientador: Leandro Borges LemosBanca: Pedro Henrique de Cerqueira Luz
Banca: Mara Cristina Pessoa da Cruz
Banca: Carlos Henrique Eiterer de Souza
Banca: Fábio Luiz Checchio Mingotte
Resumo: Os fertilizantes nitrogenados são essenciais para as culturas sob condições tropicais expressarem seus potenciais produtivos. Dentre esses fertilizantes a ureia é o mais utilizado na agricultura e devido à necessidade de redução de suas perdas por volatilização quando aplicada na superfície do solo, a ureia tornou-se o fertilizante convencional mais utilizado para o desenvolvimento de fertilizantes de eficiência aumentada. Atualmente substâncias inibidoras da enzima urease e mecanismos de revestimento de fertilizantes que alterem o fluxo de liberação de N para solução do solo, podem reduzir as perdas de N por volatilização da NH3. O trabalho foi dividido em dois estudos, com os seguintes objetivos: avaliar em condições controladas de laboratório fontes de nitrogênio convencionais e de eficiência aumentada, quanto ao controle de perdas de N por volatilização de NH3 e em um segundo estudo avaliar a eficiência de fontes e doses de nitrogênio convencionais e de eficiência aumentada em cobertura no desempenho agronômico da cultura do milho, cultivado na primeira e segunda safras 2015/2016. No experimento de laboratório, os fertilizantes utilizados foram aplicados na superfície de um latossolo vermelho argiloso, previamente umedecido a 60% da capacidade de retenção de água. Conduzido em delineamento inteiramente ao acaso com seis repetições, os tratamentos foram quatro fontes de N (ureia, ureia + NBPT, nitrato de amônio e Haya® - ureia compactada com aditivos e polímeros), além de ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Nitrogen fertilizers are essential for crops under tropical conditions express their productive potential. Among these fertilizers urea is the most widely used in agriculture and due to the need to reduce their losses by volatilization when applied on the soil surface, the urea has become the conventional fertilizer most used for the development of enhanced efficiency fertilizers. Currently urease enzyme inhibitory substances and coating mechanisms of fertilizers that alter the flow of release of N to the soil solution, can reduce N losses by volatilization of NH3. The work was divided in two studies, with the following objectives: to evaluate under controlled conditions of laboratory conventional nitrogen sources and increased efficiency, how to control N losses by volatilization of NH3 and a second study evaluate the efficiency of sources and doses of conventional nitrogen and increased efficiency in coverage on agronomic performance of the culture of corn, cultivated in the first and second harvests 2015/2016. In the laboratory experiment, fertilizers used were applied on the surface of a red loamy latosol, previously moistened the 60% water holding capacity. Conducted in entirely random design with six repetitions, the treatments were four sources of N (urea, urea + ammonium nitrate and NBPT Haya® urea compressed with additives and polymers), plus additional controls (without soil and fertilizer Chamber empty) in dose equivalent to 100 kg ha-1 of N losses were evaluated-N... (Complete abstract click electronic access below)
Doutor
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Mira, Acácio Bezerra de. "Increasing NBPT rates to reduce ammonia volatilization losses from urea applied over sugarcane straw." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-09082016-152120/.
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Urea is the main nitrogen (N) fertilizer used worldwide, but N losses in the form of ammonia (NH3) is a major problem when this fertilizer is topdressed over crop residues. The treatment of urea with N-(n-butyl) thiophosphoric triamide (NBPT) decreases the activity of urease enzyme and volatilization losses in many crops. However, the amount of straw over the soil in green cane trash blanketing (GCTB) systems affect the effectiveness of NBPT-treated urea in reducing NH3 losses. The hypothesis of this study is that an increase of NBPT concentration in NBPT-treated urea above the commercial concentration adopted nowadays (530 mg kg-1) is necessary to reduce volatilization losses and improve the efficiency of this fertilizer in GCTB systems. The aim of this study was to evaluate, under field conditions, NH3 losses from urea amended with four NBPT concentrations and applied over sugarcane straw. Six field trials were carried out across the State of São Paulo, the main sugarcane-cropped area in Brazil. It was adopted the randomized block experimental design with four replications. The treatments consisted of urea amended with the NBPT concentrations 0, 530, 850, 1500 and 2000 mg kg-1, ammonium nitrate and a control treatment (without N fertilizer). The NH3 volatilization was measured through an enclosure semi-static collector system containing two polyethylene foam discs treated with orthophosphoric acid and glycerol. The foam discs were collected and replaced at 2, 4, 6, 8, 10, 12, 16, 20, 25 and 30 days after the fertilizer application (DAF). The N trapped into the foams was extracted using deionized water and the N concentration determined by Flow Injection Analysis (FIA). Boltzmann sigmoidal models were fitted to cumulative losses of NH3 along the days. Cumulative losses between locals were compared by Tukey HSD and the effect of NBPT concentrations were tested by regression analyses (P<0.05). There was a significant effect of local and environmental conditions on amount of NH3 losses. NBPT was less effective in reducing NH3 losses under high temperatures and thick straw layer, probably because of the high urease activity and the early inhibitor degradation. The increase on NBPT concentration on urea above 530 mg kg-1 not only delayed the time of maximum rate of loss (Tmax), but also reduced cumulative NH3 losses. The two higher NBPT concentrations promoted an average delay of six days from untreated urea Tmax. Linear reduction of NH3 emissions occurred up to the NBPT concentration of 1000 mg kg-1 that reduced 43% of NH3 losses as compared to urea. Any increment in NBPT concentration above this range did not reflect in substantial reduction of NH3 losses. Increase NBPT concentration showed potential in reducing NH3 volatilization losses under GCTB sugarcane, however, further research is necessary to evaluate the impact of NH3 savings on sugarcane yield and the economic feasibility of this technology.A ureia é o principal fertilizante nitrogenado utilizado em todo o mundo, porém, perdas de nitrogênio (N) na forma de amônia (NH3) são um importante problema associado ao uso desse fertilizante. O tratamento da ureia com N-(n-butil) tiofosfórico triamida (NBPT) reduz a atividade da enzima urease e a volatilização de NH3 em muitos cultivos. Entretanto, a quantidade de palha sobre o solo em sistemas de cultivo da cana-de-açúcar colhida sem queima (CCSQ) afeta a eficiência do tratamento da ureia com NBPT em reduzir as perdas de NH3. A hipótese deste estudo é que é necessário aumentar a concentração de NBPT na ureia acima da atual concentração comercial (530 mg kg-1) para reduzir as perdas por volatilização, de modo a viabilizar o uso de ureia tratada com NBPT em sistemas de CCSQ. O objetivo desse estudo foi avaliar, em condições de campo, as perdas de NH3 de ureia tratada com quatro concentrações de NBPT e aplicada sobre a palhada de cana-de-açúcar. Seis experimentos de campo foram conduzidos no Estado de São Paulo, principal área cultivada com cana-de-açúcar no Brasil. Foi utilizado delineamento aleatorizado em blocos com quatro repetições. Os tratamentos consistiram em ureia tratada com NBPT nas concentrações 0, 530, 850, 1500 e 2000 mg kg-1, nitrato de amônio e um tratamento controle (sem adubação nitrogenada). A volatilização e NH3 foi mensurada através de sistema coletor semiestático fechado, contendo dois discos de espuma de polietileno embebidos com solução de ácido ortofosfórico e glicerina. Os discos de espuma foram coletados e substituídos aos 2, 4, 6, 8, 10, 12, 16, 20, 25 e 30 dias após a aplicação dos fertilizantes (DAF). O N retido nas espumas foi extraído usando água deionizada e a concentração de N determinada por Análise por Injeção em Fluxo (FIA). Modelos sigmoides de Boltzmann foram ajustados para as perdas cumulativas de NH3 ao longo dos dias. As médias das perdas acumuladas entre locais foram comparadas usando teste de Tukey e o efeito das concentrações de NBPT foi testado por análise de regressão (P<0,05). Houve forte influência do local e das condições ambientais nas perdas de NH3. O NBPT foi menos eficiente reduzir as perdas de NH3 em condições de alta temperatura e grossa camada de palha, provavelmente devido à alta atividade de urease e à degradação prematura do inibidor. O aumento na concentração de NBPT na ureia acima de 530 mg kg-1 não apenas retardou o pico de máxima taxa de perda diária (Tmax), mas também reduziu as perdas acumuladas de NH3. As duas maiores concentrações de NBPT promoveram um retardamento médio de seis dias em relação ao Tmax da ureia. Uma redução linear nas emissões de NH3 foi verificada até a dose de 1000 mg kg-1 de NBPT, que levou a uma redução de 43% nas perdas em comparação à ureia não tratada. Incrementos na concentração de NBPT acima desse valor não se refletiram em redução substancial das perdas de NH3. Aumentar a concentração de NBPT na ureia demonstrou potencial em reduzir as perdas e NH3 por volatilização em sistemas de CCSQ, entretanto são necessárias mais pesquisas avaliando o impacto do N preservado no sistema sobre a produtividade da cana-de-açúcar e a viabilidade econômica dessa tecnologia.
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Båth, Birgitta. "Matching the availability of N mineralised from green-manure crops with the N-demand of field vegetables /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2000. http://epsilon.slu.se/avh/2000/91-576-5754-8.pdf.
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