Peatland ecosystems only cover 2-3 % of the Earth‟s surface but they represent significant carbon stores, holding approximately one third of the global soil carbon (C). The major peat forming genera Sphagnum appears to be highly sensitive to increased N availability. Many studies have shown decreased productivity of Sphagnum which could lead to a decrease in the amount of C stored, especially as many studies also show an increase in the decomposition rate with higher N deposition. However, the overall effects of N on CO2 fluxes of Sphagnum remain unclear. The present study aimed to look at the effects of increased N on Sphagnum productivity, decomposition and CO2 fluxes after long-term N additions (> 5 years) using a field experiment at Whim Moss in southern Scotland where N deposition has been manipulated employing a very realistic application coupled to rainfall since 2002. The experiment also has treatments with PK addition to test the effects of removing P and/or K-limitation. Measurements of plant tissue nutrient concentrations, visual assessments of Sphagnum viability, and pore water analysis were also carried out. Nitrogen additions increased tissue N, and decreased Sphagnum shoot extension and productivity. Simultaneous P and K additions alleviated the effects of N on tissue N concentrations and growth, although this was only significant for shoot extension. Visual assessments correlated well with tissue chemistry and productivity; the decline in health was associated with high %N and reduced productivity. Interestingly, in the present study increased N decreased the mass loss and again when PK was added with N decomposition rates were more similar to the control. With respect to the carbon balance of the site and the sustainability of peatlands the results suggest that the negative effect of N on C assimilation may be partially offset by the reduced decomposition rates. The CO2 measurements showed a large loss of C as CO2 from all the Sphagnum plots which was exacerbated by adding N especially when the air temperature increased. The positive temperature response of ecosystem respiration with N additions suggests that in high N deposition areas climate change and subsequent temperature rises will increase C losses from bogs.

Resumo: Na fabricação de gelatina, são gerados resíduos que, particularmente pela concentração de N, são de interesse para uso agrícola. Os objetivos com este trabalho foram verificar o potencial do lodo biológico de indústria de gelatina (LB) em fornecer nitrogênio para plantas de milho e avaliar a resposta das plantas de milho à aplicação do LB. O LB foi fornecido pela Gelita do Brasil, unidade de Mococa (SP). Ao todo, foram conduzidos seis experimentos: dois em laboratório, dois em casa de vegetação e dois em campo. Para os experimentos em laboratório e em casa de vegetação, foram coletadas amostras de Argissolo Vermelho do local onde foram instalados os experimentos de campo, em Mococa. No laboratório e na casa de vegetação, as doses de LB avaliadas foram equivalentes a 0; 100; 200; 300; 400 e 500 m3 ha-1. Com base nesses experimentos, concluiu-se que o carbono e o nitrogênio orgânico do lodo biológico de indústria de gelatina foram rapidamente mineralizados no solo, com tempo médio de meia-vida de 8,1 e 7,8 dias, respectivamente. Os métodos de incubação aeróbia e anaeróbia foram eficientes em prever a disponibilidade de nitrogênio do lodo biológico para plantas de milho e com base no primeiro foi determinada a taxa de aplicação do LB para os experimentos em campo (85 m3 ha-1). Em um dos experimentos em campo, foram avaliadas doses equivalentes a 0,5; 1,0; 1,5 e 2,0 vezes a taxa de aplicação do LB e foi obtido aumento linear na produtividade de grãos de milho safrinha. No outro experimento em condição de campo, em que a dose de N para milho safrinha foi de 50 kg ha-1 de N, associando NH4NO3 e LB, em diferentes proporções, a produtividade não foi afetada pela fonte de N. / Abstract: In the gelatin manufacturing process many wastes are generated and particularly by their N concentrations, these wastes can be used for agricultural purpose. The objectives of this study were to evaluate the potential of gelatin industry sludge (GIS) to provide nitrogen for maize plants and to evaluate the response of maize plants to GIS application. The GIS was supplied by Gelita do Brasil, subsidiary in Mococa (Sao Paulo State, Brazil). Six experiments were carried out: two in laboratory, two in greenhouse and two under field conditions. Kandiudult samples were collected from the area where the field experiments were installed, in Mococa, and these soil samples were used in laboratory and greenhouse studies. In laboratory and greenhouse the GIS rates evaluated were equivalent to 0; 100; 200; 300; 400 and 500 m3 ha-1. Based on these experiments it was concluded that organic carbon and nitrogen from GIS were rapidly mineralized in soil, with average half-life of 8.1 and 7.8 days, respectively. Long-term aerobic and anaerobic incubations were effective in predicting the nitrogen availability from GIS to maize plants and from aerobic incubation data it was determined the GIS application rate for field experiments (85.5 m3 ha-1). In one of the field study, rates equivalents to 0.5, 1.0, 1.5 and 2.0 times the GIS application rate were evaluated and it was obtained a linear increase in the out of season maize grain yield. In another field experiment, in which the recommended N rate for out of season maize was 50 kg ha-1 N, ammonium nitrate and GIS were associated in different proportions, maize grain yield was not affected by N source. / Orientador: Manoel Evaristo Ferreira / Coorientadora: Mara Cristina Pessôa da Cruz / Banca: William Natale / Banca: José Frederico Centurion / Banca: Dirceu Maximino Fernandes / Banca: José Ricardo Mantovani / Doutor

Made available in DSpace on 2014-06-11T19:31:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-22Bitstream added on 2014-06-13T19:40:47Z : No. of bitstreams: 1 taniguchi_cak_dr_jabo.pdf: 1062568 bytes, checksum: bc86d88e56e243b9e6b9c324c687bcd6 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Gelita do Brasil S.A. / Na fabricação de gelatina, são gerados resíduos que, particularmente pela concentração de N, são de interesse para uso agrícola. Os objetivos com este trabalho foram verificar o potencial do lodo biológico de indústria de gelatina (LB) em fornecer nitrogênio para plantas de milho e avaliar a resposta das plantas de milho à aplicação do LB. O LB foi fornecido pela Gelita do Brasil, unidade de Mococa (SP). Ao todo, foram conduzidos seis experimentos: dois em laboratório, dois em casa de vegetação e dois em campo. Para os experimentos em laboratório e em casa de vegetação, foram coletadas amostras de Argissolo Vermelho do local onde foram instalados os experimentos de campo, em Mococa. No laboratório e na casa de vegetação, as doses de LB avaliadas foram equivalentes a 0; 100; 200; 300; 400 e 500 m3 ha-1. Com base nesses experimentos, concluiu-se que o carbono e o nitrogênio orgânico do lodo biológico de indústria de gelatina foram rapidamente mineralizados no solo, com tempo médio de meia-vida de 8,1 e 7,8 dias, respectivamente. Os métodos de incubação aeróbia e anaeróbia foram eficientes em prever a disponibilidade de nitrogênio do lodo biológico para plantas de milho e com base no primeiro foi determinada a taxa de aplicação do LB para os experimentos em campo (85 m3 ha-1). Em um dos experimentos em campo, foram avaliadas doses equivalentes a 0,5; 1,0; 1,5 e 2,0 vezes a taxa de aplicação do LB e foi obtido aumento linear na produtividade de grãos de milho safrinha. No outro experimento em condição de campo, em que a dose de N para milho safrinha foi de 50 kg ha-1 de N, associando NH4NO3 e LB, em diferentes proporções, a produtividade não foi afetada pela fonte de N. / In the gelatin manufacturing process many wastes are generated and particularly by their N concentrations, these wastes can be used for agricultural purpose. The objectives of this study were to evaluate the potential of gelatin industry sludge (GIS) to provide nitrogen for maize plants and to evaluate the response of maize plants to GIS application. The GIS was supplied by Gelita do Brasil, subsidiary in Mococa (Sao Paulo State, Brazil). Six experiments were carried out: two in laboratory, two in greenhouse and two under field conditions. Kandiudult samples were collected from the area where the field experiments were installed, in Mococa, and these soil samples were used in laboratory and greenhouse studies. In laboratory and greenhouse the GIS rates evaluated were equivalent to 0; 100; 200; 300; 400 and 500 m3 ha-1. Based on these experiments it was concluded that organic carbon and nitrogen from GIS were rapidly mineralized in soil, with average half-life of 8.1 and 7.8 days, respectively. Long-term aerobic and anaerobic incubations were effective in predicting the nitrogen availability from GIS to maize plants and from aerobic incubation data it was determined the GIS application rate for field experiments (85.5 m3 ha-1). In one of the field study, rates equivalents to 0.5, 1.0, 1.5 and 2.0 times the GIS application rate were evaluated and it was obtained a linear increase in the out of season maize grain yield. In another field experiment, in which the recommended N rate for out of season maize was 50 kg ha-1 N, ammonium nitrate and GIS were associated in different proportions, maize grain yield was not affected by N source.

For this dissertation, I examined the ability of field-grown plants to capture N presented in enriched patches or in whole-plant pulses. I assessed root proliferation in N-enriched patches when Agropyron desertorum plants had been previously fertilized or shaded. All plants responded with increased root growth rates in N-enriched patches. However, root proliferation by shaded plants was 50% less than unshaded plants. Unexpectedly, plants with higher N status had greater root growth rates in enriched patches than plants that had not received N supplement. I concluded that plants already under competitive pressure above ground for light and below ground for nutrients should be less able to respond to opportunities presented in nutrient patches. I then examined plant growth responses and biomass production of six Great Basin species (Bromus tectorum, Taeniatherum medusae, Agropyron desertorum, Pseudoroegneria spicata, Artemisia tridentata, and Chrysothamnus nauseosus) following a pulse ofN applied in the early, mid, or late spring. An equal quantity of N, applied continuously, was a control. Surprisingly, most of the species grown under the continuous supply had lower growth rates and less biomass production than plants recieving an N pulse. The exception was Chrysothamnus, which responded equivalently to all treatments. Generally, the greatest response occurred in early phenological stages. Four of the six species had their greatest response to the early-spring pulse, suggesting that these cold-season species are well-adapted to take advantage of early spring nutrient pulses. This study demonstrated that instead of benefitting from a season-long supply of N, there were times during the growing season when plants were able to use pulses of N for significant gains in biomass. I also investigated the root properties (root biomass, specific root length [the ratio of root length:root mass], and root uptake capacity) that determined plant response to pulses. Despite considerable temperature differences and changes in plant phenological stages, root uptake capacity remained remarkably constant throughout the season. However, this consistency did not explain the differences in productivity during the season. Root biomass also did not explain these growth responses to pulses. Instead, I suggest that the quantity of actively growing fine roots, plus the ability to effectively exploit the soil volume in the early spring, results in capture of early nutrient pulses.

Calendula officinalis is a useful model crop because calendula flowers are used both ornamentally and medicinally. Organic production systems have many challenges; among these is the synchrony of nitrogen mineralization with the requirements of the crop. Organic greenhouse substrates have significantly different initial nitrogen levels which influence the performance of calendula, the highest initial N and plant performance was found in the organic compost peat substrate (OCP). The addition of supplemental nitrogen improved performance, but only OCP performed as well as the conventionally fertilized peat-based substrate. The nitrogen mineralization patterns in a soil-based greenhouse pot experiment showed that highly processed amendments supplied the highest levels of nitrogen, and that these amendments showed greater vegetative growth when soil was amended with a high-input amendment, but flower production was reduced. There was no observed influence of water stress on nitrogen mineralization, but flowers from water stressed plants had approximately 50% higher concentrations of secondary compounds than non-stressed flowers. Nitrogen mineralization in organic production systems is difficult to predict, but highly influences plant productivity and performance.

AN ABSTRACT OF THESIS Jarrod Armstrong, for the Master of Science degree in Forestry, presented on December 10, 2014, at Southern Illinois University Carbondale. Title: Nitrogen Availability and Transport Following Drought in Three Agricultural Watersheds in Central Illinois Major Professor: Dr. Karl Williard The use of inorganic nitrogen (N) fertilizers has become an essential part of modern agriculture and has helped increase yields to keep pace with an ever growing population. N is the most dynamic nutrient in nature, and biological activity can transform it into several mobile forms. Nitrate (NO3-N) is the most mobile form of N and is highly susceptible to transport to ground and surface waters. The purpose of this study was to assess N dynamics in three agricultural watersheds during and following a significant drought in 2012. Specifically, the study focuses on the mobilization and transport of residual N. The research was conducted on a ninety‐seven hectare agriculture field in Macon, County Illinois. The study site (BRKA) was divided into three watersheds, with four plots per watershed, and two topographic positions per plot. Volumetric water content (VWC) was measured continuously in each of the two topographic positions. In each watershed, stream stage collected over storm hydrographs using automated water samplers was compared to volumetric water content and NO3-N concentrations over the hydrograph. Four 6.1m groundwater monitoring wells and eight vacuum lysimeters in each watershed were monitored to determine the fate and transport of N to soil water and groundwater. Soil sampling at the 15cm depth was completed on a 0.4 hectare grid over the entire field during the fall of each year of the study. Soil and groundwater samples were analyzed monthly to compare NO3-N concentrations across topographic positions. NO3-N concentrations were highest in soil water, followed by groundwater, and lastly surface runoff. Studies in Illinois and Iowa both confirmed large amounts of residual N in the soil after the growing season in the fall of 2012 (Sawyer 2013, and Nafziger 2013). Residual N was apparent at BRKA in elevated NO3-N concentrations in soil water and groundwater after the 2012 growing season. Runoff events in April 2013 also showed increased NO3-N transport. However, due to precipitation events in the late fall and winter the residual N was flushed from the soil profile rendering it unavailable for the 2013 growing season. The soil NO3-N deficit after the 2012 drought was likely the result of decreased N fixation, N mineralization, nitrification, and leaching of any residual NO3-N. Bottomland positions consistently displayed higher soil water and groundwater NO3-N concentrations compared to uplands. However, due to a lack of plant uptake during the 2012 drought this trend was reversed and caused upland positions to exhibit higher NO3-N concentrations compared to bottomlands. This study demonstrated that even during a soybean year when no N fertilizer was applied significant drought can effectively alter the normal N dynamics at the field scale. Furthermore, this change in dynamics can lead to elevated NO3-N concentrations in soil water and ground water. These findings also suggest that precipitation events following periods of drought, like those observed after the 2012 growing season, can flush excess nutrients from the rooting zone further depleting the NO3-N pool and posing a risk to water quality. Data from a June 15, 2011 storm showed that on the falling limb of the hydrograph subsurface flow flushed soil water from the top of the slope to the bottom of the slope. This is indicative of a variable source area controlled watershed where the near stream zones undergo prolonged saturation from the subsurface drainage of the upland areas. Additionally, the early peak of NO3-N during an April 18, 2013 surface runoff event could be attributed to increased mineralization and nitrification following a rewetting of the soil profile after the 2012 drought. Lastly, topography was shown to have a strong influence on soil NO3-N concentrations across the field. This finding suggests that fertilizer applications based on topography and hydrology could help to mitigate the loss of excess NO3-N from agricultural watersheds. Furthermore, fertilizer applications should be adjusted for drought conditions that extend into the following growing season to account for residual N in the soil.

京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第22905号 / 地環博第206号 / 新制||地環||40(附属図書館) / 京都大学大学院地球環境学舎地球環境学専攻 / (主査)教授 舟川 晋也, 准教授 渡邉 哲弘, 准教授 舘野 隆之輔 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21968号 / 農博第2358号 / 新制||農||1070(附属図書館) / 学位論文||R1||N5219(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 北山 兼弘, 教授 小杉 緑子, 教授 舟川 晋也 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

In situ measurements of soil nitrogen dynamics is a potential method for evaluating the health of constructed wetlands following oil sands mining. The objective of this study is to measure and compare the soil nitrogen availability of a reclaimed fen (Sandhill fen) with a nutrient-rich reference fen (Poplar fen) and a nutrient-poor reference fen (Pauciflora fen) in the Athabasca oil sands region of northern Alberta. Total Nitrogen (TN), Nitrate (NO3-) and Ammonium (NH4+) supply rates were determined along wetland hillslope transects using Western Ag Innovations Plant Root Simulator (PRSTM) probes at all three sites in 2014. Net N mineralization, net nitrification and net ammonification were determined simultaneously using the buried polyethylene bag sampling method. Overall, TN supply rates were greatest at the poor fen and least at the constructed Sandhill fen. In contrast, mineralization was greatest at the rich fen but again least at the Sandhill fen. Mineralization at the Sandhill fen was controlled evenly by ammonification and nitrification, whereas the two natural sites were controlled by ammonification. Relatively low N supply rates and mineralization at the Sandhill fen were likely due to lower soil organic matter and limited soil moisture in these newly constructed substrates. Spatial differences along the hillslopes also varied among sites. The Sandhill fen had higher TN supply rates at the upslope positions but no significant differences in net N mineralization rates along the hillslopes. The rich fen also had higher TN supply rates at the upslope but greatest mineralization rates downslope. These results highlight the importance of N storage and transport processes and offer insight into the N status of a constructed fen. / Thesis / Master of Science (MSc)

Biosolids have been used as soil conditioners and fertilizers in agriculture and mine land reclamation, but application of Exceptional Quality (EQ) biosolids to rehabilitate anthropogenic soils for urban agriculture is recent and requires greater study to ensure their appropriate use. The objectives were: 1) to quantify plant available nitrogen (PAN) of new EQ biosolids in a greenhouse bioassay; 2) to quantify PAN of EQ biosolids applied to an urban degraded subsoil via tall fescue N fertilizer equivalency, and compare field results to laboratory tests; 3) to investigate EQ biosolids and inorganic fertilizer effects on urban soil properties, vegetable yields, and potential N and phosphorus (P) loss. Biosolids evaluated were products of thermal hydrolysis plus anaerobic digestion (BLOOM), blending with woody mulch (BM) and sand/sawdust (BSS), composting (LBC), and heat-drying (OCB). Organic N mineralization of new blended biosolids products ranged between 20-25% in the greenhouse bioassay. Products BLOOM, BM, and OCB had the highest organic N mineralization as estimated by the 7-day anaerobic incubation, and this test and soil nitrate-N had the highest correlations with tall fescue N uptake (r=0.49 and r=0.505, respectively). We conducted a two-year field study with four growing seasons (fall 2016-2017 and summer 2017-2018) in an urban disturbed subsoil where EQ biosolids were applied seasonally at agronomic N rates, and yearly at reclamation rates (5x agronomic N). Cabbage yields were greater with reclamation rates (~3.0 kg m-2) and bell pepper yields were greater with BLOOM reclamation rate (~1.0 kg m-2) than with the inorganic fertilizer (1.0 kg m-2 and 0.2 kg m-2, respectively) during second year growing seasons. Soil carbon (C) accumulation (%C remaining in the soil) two years after biosolids additions ranged between 37 to 84%. Soil N availability and mineralization were limited most likely due to lack of residual soil C and N, and high clay content. Nitrogen leaching losses from reclamation rates were not greater than agronomic N rates. Leachate P was below detection during most of the experiment. Despite limiting soil conditions, biosolids amendment at reclamation rates showed greatest potential to increase vegetable yield and improve soil properties after two years of application, while not impairing water quality. / Doctor of Philosophy / Exceptional Quality (EQ) biosolids are by-products of wastewater treatment plants that have been processed to destroy pathogens, reduce attraction by disease-spreading organisms (e.g. flies, mosquitoes, rodents, etc.), and limit heavy metal concentrations. These characteristics make EQ biosolids safe for use by home gardeners for growing food crops. There is limited information on optimal recommended rates at which these products should be applied to urban gardens. The purpose of our research was to determine optimum application rates of EQ biosolids to urban gardens based on their essential plant nutrient (esp., nitrogen and phosphorus) availability. We learned that the EQ biosolids we studied are less concentrated in plant available nitrogen and phosphorus than biosolids applied to conventional agricultural fields. This is because we diluted our biosolids with sawdust, sand, and woody mulch to facilitate their storage, handling, and ease of application. We learned that high EQ biosolids application rates reduce soil compaction and increase essential plant nutrient availability and crop yields for agriculture practiced in urban soils. The high application rates of EQ biosolids accomplished such soil-improving and yield-increasing benefits without impairing local water quality.