Overapplication of manure in sensitive watersheds is an issue of increasing environmental concern due to increased nutrient loading and antibiotic release into aquatic environments. Manure is typically surface applied, leaving nutrients and antibiotics vulnerable to loss at the soil surface. Elevated nutrient and antibiotic loading into water bodies can increase the rate of eutrophication and occurrence of antibiotic resistance genes in areas of high animal agriculture production, such as the Chesapeake Bay watershed. Manure injection is a new technology that incorporates manure into the soil with minimal disturbance, and management strategies that reduce manure loss from agricultural fields could prevent the transport of nutrients and antibiotics to sensitive waterways. However, little is known about the efficacy of dry litter injection to decrease nitrogen (N) loss when compared to surface application. Also, there are no studies that determine the effects of injection on antibiotic transport and transformation after manure application. Therefore, this project focused on changes in N cycling, orchardgrass hay yield and quality, and transport and transformation of pirlimycin and cephapirin, two common antibiotics in dairy production, when manure is injected. Subsurface injection eliminated ammonia volatilization and N loss in runoff and increased soil inorganic N when compared to surface application after volatilization, incubation, and rainfall simulation studies. Although these benefits did not translate to higher yields in orchardgrass hay, protein increased when poultry litter was injected, indicating greater N uptake. Injection of dairy manure decreased losses of pirlimycin to levels of the control when compared to surface application. Although, pirlimycin had a slower degradation rate within the injection slit compared to surface application, potentially increasing the amount of time soil microbes are exposed to antibiotics. In an incubation study, pirlimycin concentrations decreased after 7 days, but concentrations increased sharply after 14 days. This indicates that conjugates formed in the liver or digestive tract of dairy cows may revert back to the parent compound after manure application. With increased retention of nutrients and antibiotics, injection could be a best management practice used to reduce the loss of these compounds to the environment while increasing the quality of crops produced. / Ph. D.

AN ABSTRACT OF THE THESIS OF BRENT C. SUNDERLAGE, for the Master of Science degree in Plant, Soil, and Agricultural Systems, presented on March 8, 2017, at Southern Illinois University Carbondale. TITLE: LATE APPLICATION NITROGEN ON CORN IN SOUTHERN ILLINOIS AND SOIL PROPERTIES AFFECTING AMMONIA VOLATILIZATION FROM UREA FERTILIZER MAJOR PROFESSOR: Dr. Rachel L. Cook In corn (Zea mays L.) production systems, typical nitrogen fertilization occurs either before planting or after crop emergence, as late as the V6 stage. Since the majority of nitrogen uptake does not occur until V10 through R1, delaying nitrogen fertilization until V10 may reduce potential for early season soil N transformations and losses, while sustaining crop yields. A two-year study, conducted across three southern Illinois locations, evaluated the effects of various late sidedress nitrogen applications and enhanced efficiency fertilizers on corn yield and residual mineral soil N. The various nitrogen treatments compared: rates from 0-224 kg N ha-1; sources of urea and 32% UAN, with and without urease inhibitors 0.09% N-(n-butyl) thiophosphoric triamide (NBPT) as Agrotain® Ultra (AT) and 0.06% NBPT + 0.02% N-(n-propyl) thiophosphoric triamide (NPPT) as Limus® (L), and polymer-coated urea (ESN®); application timings at planting, V6, V10, and VT; placement either dribble applied, broadcasted, or injected. Across sites and years, late (V10) nitrogen split applications generally resulted in corn yields greater than or equal to the same total nitrogen rate applied at planting. Most late N treatment differences varied between sites and years, but 56 kg N ha-1 as broadcasted UAN at planting with 112 kg N ha-1 as broadcasted urea, either with or without AT or L at V10 were on average highest yielding treatments among sites in both years, with 16% greater yield than 168 kg N ha-1 as broadcasted UAN at planting. Urease inhibitors did not enhance yield in most instances, likely due to sufficient incorporating rainfall shortly after application. The effects of urease inhibitors used with late-application nitrogen on corn yield and actual ammonia volatilization remained ambiguous. Residual soil mineral nitrogen concentrations between 0-30 cm after harvest in the late nitrogen treatments did not elicit water quality concerns. Furthermore, ammonia volatilization from surface applied urea is controlled by many interrelated soil properties as well as environmental conditions. However, conclusions about the influence of soil properties on ammonia volatilization differ according to geographies and are not well established across a wide range of soil types. A laboratory soil incubation experiment measured the effects of soil properties on ammonia volatilization over 7 days from surface-applied urea and the efficacy of three urease inhibitors: Agrotain® Ultra (AT) as 0.09% NBPT, Limus® (L) as 0.06% NBPT + 0.02% NPPT, and NutriSphere-N® (NS) 30% calcium salt of maleic-itaconic copolymer among 83 soil surface samples from across the United States with a wide range of soil properties. The soil properties evaluated were: total exchange capacity, 1:1 CaCl2 pH, organic matter, buffering capacity, clay content, and urease activity. In Urea (R2 = 0.69) and Urea + NS (R2 = 0.62) models, total exchange capacity, clay, and buffering capacity significantly reduced ammonia volatilization, and organic matter significantly increased ammonia volatilization, while 1:1 CaCl2 pH and urease activity were non-significant. Clay, organic matter, and buffering capacity were correlated to total exchange capacity. Total exchange capacity was the strongest predictor and best consolidated variable to predict N loss of urea. In Urea + AT (R2 = 0.54) and Urea + L (R2 = 0.67) models, ammonia volatilization was significantly reduced at lower 1:1 CaCl2 pH and total exchange capacity, and all other soil properties were non-significant. The NBPT in Urea + AT and Urea + L likely decayed more rapidly under acidic soil conditions, resulting reduced NBPT efficacy and greater N loss at lower pH. Urea + AT and Urea + L reduced volatilization significantly by 18.2 percentage points compared to Urea or Urea + NS, and there were no significant differences between Urea + AT and Urea + L (α = 0.05). On average, NutriSphere-N® did not reduce volatilization.

Made available in DSpace on 2015-03-26T13:53:12Z (GMT). No. of bitstreams: 1 texto completo.pdf: 350943 bytes, checksum: 3e5a0839007773fc7b7183796a3f68d1 (MD5) Previous issue date: 2010-02-22 / In spite of its large quantity found in soil, N is one of the major factors that limit crop production, because the nitrate and anmonium that are preferably absorbable by plants account for less than 2 % of the total N in the soil. For this limitation, it is necessary to use nitrogen fertilization to meet crop requirements emphasizing the urea usage. Despite this, urea demonstrates low agronomic efficiency due to the NH3 loss by volatilization, as the nitrogen fertilization is usually performed on coverage with application on the soil surface. Several alternatives are listed in order to reduce losses. Among them are: the mode of application of urea, the period of fertilization and the production of urea with larger granules. Given the above, this study aimed to evaluate the NH3 loss by volatilization, the absorbed N, and the production by corn plants fertilized with different forms of urea. This work also aimed to evaluate the N loss by ammonia volatilization and the N supply to corn plants by urea in its pearled and granulated form, coated with humic acids synthesized from eucalyptus charcoal. An experiment was installed in a Red-and-Yellow cambic Acrisol, cultivated for several years and which now shows good fertility. We evaluated the PETROBRAS pearled urea (UPP), pearled urea UPI, PETROBRAS granulated urea (UGP), granulated urea UGI and special granulated urea (UTI). The dosages of fertilization on coverage were: 0, 40, 80, 120 and 160 kg ha-1 N. We evaluated the application of topdressing at the growth stage of corn characterized by the second, fourth and sixth fully expanded leaves and also the application of superficial urea (S) and incorporated to 5 cm depth (I), both in line next to the plants. These factors were combined according to an incomplete factorial, a Baconian matrix, resulting in 19 treatments, plus an additional treatment corresponding to the absence of nitrogen fertilization on coverage. Treatments were arranged in a randomized block design with three replications. Data from volatilization of NH3, number and weight seed by ear of corn, yield corn, content and N recovery were by corn plants subjected to analysis of variance with regression fits and comparisons using contrasts. In another experiment we evaluated the pearled (UPP) and granulated (UPG) urea produced by PETROBRAS and the special granulated urea (UTI), uncoated or coated with 200, 120 and 80 g kg-1 of humic acid, respectively, applied onto the soil surface or incorporated to 3 cm depth resulting in a factorial (3 x 2 x 2) + 1, which corresponds to the treatment without topdressing. The experiment was conducted in a greenhouse using corn in pots with 5 dm³ of an Oxisol in a completely randomized design with four replications. The humic acids were synthesized from eucalyptus charcoal obtained with final carbonization temperature of 350 °C. The variables analyzed were: dry matter, amount of absorbed and accumulated N, NH3 volatilization, content of NO3- and NH4+ in the soil. Data were subjected to analysis of variance. The plots fertilized with the UPP showed same losses of NH3 as for plots fertilized with the other N sources in surface. The plots UGP fertilized plots showed NH3 losses significantly higher than the ones fertilized with UGI. In incorporated application promoted less NH3 volatilization compared with surface application demonstrating the efficiency of fertilizer management practices. UPI promoted higher corn yields than UPP. The UGI, UGP and UTI forms of granulated urea favored an equivalent yield to the obtained with UPP. The yield corn was not altered by the period of the nitrogen fertilization application, indicating that N can be applied when the plant has two open leaves. The yield did not differ between the treatments with incorporated and superficial application of urea. The effects of coating with humic acids for each urea and the effects of the application form for each urea with or without coating were compared using the F test (p <0.05). The mean effects of the forms of urea were compared with the treatment without fertilization of coverage (additional treatment) by means of orthogonal contrasts (p <0.05). The characteristics of humic acids were similar to those found in the literature, indicating that the methodology is feasible for production. The volatilization of NH3 and dry weight of plants were not affected by the use of humic acids as a coating for the forms of urea, however, for N uptake and apparent recovery of N there was a positive effect indicating that the coating of the UPP is advantageous when applied superficially. / O N é um dos nutrientes requerido em maior quantidade pelas plantas e é o que mais limita o seu crescimento. Na maioria dos solos o N é encontrado em quantidades que seria suficiente para atender a demanda das culturas, porém uma grande proporção está em forma orgânica do solo e com elevada recalcitrância. Assim, a adubação nitrogenada se faz necessária e, atualmente, a ureia é o fertilizante mais utilizado. Apesar disto, a eficiência agronômica da ureia é comprometida, considerando que a maior proporção das doses do N é aplicada na adubação de cobertura na superfície do solo. Nestas condições a perda de N pela volatilização de NH3 é intensa. Alternativas de manejo da adubação variando o modo e a época de aplicação da ureia e industriais, como a produção de ureia com diferente granulometria, com ou sem aditivos que controlem a hidrólise da ureia, contribuem para diminuir a volatilização da NH3. Este trabalho objetivou avaliar a volatilização de NH3, o N absorvido, o crescimento e a produção de plantas de milho adubadas com ureia perolada e granulada, revestida, ou não, com ácidos húmicos sintetizados a partir de carvão de eucalipto. Foi realizado um experimento em campo, em um Argissolo Vermelho-Amarelo cambico, cultivado há vários anos e com boa fertilidade atual. Avaliou-se a ureia perolada da PETROBRAS (UPP - 446 g kg-1 de N), a ureia perolada UPI (446 g kg-1 de N); a ureia granulada da PETROBRAS (UGP - 449 g kg-1 de N), a ureia granulada UGI (445 g kg-1 de N) e a ureia granulada especial UTI (451 g kg-1 de N). As doses na adubação de cobertura foram: 0, 40, 80, 120 e 160 kg ha-1 de N. Avaliou-se, ainda, a aplicação da adubação de cobertura quando o milho apresentava duas, quatro e seis folhas expandidas e a aplicação da ureia superficial e incorporada à 5 cm, ambas em linha ao lado das plantas. A combinação destes fatores resultou em 19 tratamentos, de açodo com um fatorial incompleto, denominado matriz Baconiana, acrescido de um tratamento adicional, que correspondeu à ausência de adubação nitrogenada de cobertura. Os tratamentos foram dispostos em um delineamento experimental de blocos ao acaso com três repetições. As parcelas experimentais (4,9 x 10,0 m) foram compostas de sete linhas de milho de 10 m de comprimento, espaçadas de 70 cm. A área útil da parcela (16,8 m2) foi constituída pelas três fileiras centrais, eliminando-se 1 m de cada extremidade. Em parcelas de alguns tratamentos foram instalados coletores de amônia semi-abertos estáticos para quantificar as perdas de amônia aos 3, 7, 12, 19 e 26 d após a adubação de cobertura. No final do ciclo vegetativo do milho quatro plantas foram cortadas rente ao solo e dissecadas em colmo, folha, espiga e pendão. O material vegetal foi seco, pesado e analisado para determinação do teor de N. Ao final do ciclo quantificou-se a produtividade de grãos, o número e peso médio de grãos por espiga. Estimou-se o N absorvido pela população de plantas de milho e a recuperação aparente do N suprido pelas formas de ureia. Em outro experimento em casa de vegetação avaliou-se a UPP, a UGP e a UTI, sem revestimento ou revestidas com 200, 120 e 80 g kg-1, de ácidos húmicos, respectivamente e aplicadas na superfície do solo ou incorporada a 3 cm de profundidade. Assim, os tratamentos resultaram da combinação fatorial (3 x 2 x 2) + 1, que correspondeu ao tratamento sem adubação de cobertura. Os ácidos húmicos foram sintetizados a partir de carvão de eucalipto obtido com temperatura final de carbonização de 350 ºC. O delineamento experimental foi blocos casualisados, com 4 repetições. As unidades experimentais foram vasos com 5 dm3 de um Latossolo Vermelho- Amarelo. Em cada vaso foram instalados coletores de amônia semi-abertos dinâmico. Trinta dias após a adubação de cobertura as plantas foram cortadas rente ao solo. Determinou-se a matéria seca acumulada e o seu teor de N. No experimento em campo constatou-se que a aplicação superficial da UPP e das demais formas de ureia apresentaram quantidade equivalente de NH3 volatilizada. As parcelas fertilizadas com a UGP apresentaram perdas de NH3 significativamente maiores do que aquelas fertilizadas com a UGI. A aplicação incorporada promoveu menor volatilização de NH3 do que a aplicação superficial demonstrando a eficiência desta pratica de manejo da adubação. A UPI promoveu maior produtividade de milho do que a UPP. As formas de ureia granulada UGI, UGP e UTI favoreceram produtividade de milho equivalente a obtida com a UPP. A produtividade do milho não foi alterada pela época de aplicação da adubação nitrogenada, indicando que o N pode ser aplicado quando a planta apresentar duas folhas abertas. A produtividade do milho não diferiu entres os tratamentos com aplicação superficial e incorporada da ureia. O revestimento das ureia perolada (UPP) e granulada (UPI e UTI) com ácidos húmicos não proporcionou menor volatilização de NH3 nem maior acumulo de matéria seca nas plantas de milho. No entanto, para UPP aplicada na superfície do solo o revestimento com ácidos húmicos condicionou maior quantidade de N absorvido e maior recuperação aparente de N pelas plantas de milho.

Within Arkansas, Louisiana, Mississippi, Missouri, and Texas, rice acreage is rotated with soybean due to both crops’ adaptability to the clay soils of the midsouthern USA. Two row patterns, two maturity groups, and six seeding rates were examined at Stoneville, MS, in 2009-2010, with respect to soybean growth and yield produced on silt loam soil. Optimal yield for MG IV was 333,000 seed ha-1 (297,000 plants ha-1). Twin-row soybean increased seed yield 7 to 10% more than single-row due to greater LAI, NDVI, and node and pod production. Rice field experiments quantified N loss via ammonia volatilization and determined grain yield for various N sources and preflood application timing. Cumulative ammonia volatilization loss on Tunica clay was minimal (10% of applied N). Grain yields were 6% less when fertilizer was applied 10 days before flood (dbf) as compared to 1 dbf; N sources are available to minimize ammonia volatilization loss.

O manejo eficiente de fertilizações nitrogenadas em sistemas de exploração a pasto é peça chave para que melhores índices produtivos sejam alcançados. O conhecimento das perdas intrínsecas a esta prática e de fontes nitrogenadas alterntivas às normalmente usadas proporciona a determinação de melhores eficiências e flexibilidade na escolha da forma do nitrogênio aplicado. Assim o presente estudo teve o objetivo de avaliar as perdas por lixiviação de nitrato e volatilização de amônia, juntamente com a recuperação aparente do nitrogênio, em pastagens de capim elefante manejadas sob elevada fertilidade do solo. O experimento foi conduzido em área do depzrtamento de Zootecnia da ESALQ/USP, em Piracicaba. Adotou-se o delineamento experimental blocos ao acaso, com quatro blocos e seis tratamentos, que constaram da aplicação de 100 kg de N.ha-1 por ciclo, sob a forma de uréia, nitrato de amônio, etserco de curral, cama de frango e ajifer. Ao todo foram realizados três ciclos de amostragem, de novembro de 2006 a fevereiro de 2007, totalizando a aplicação de 300 kg de N.ha-1. Todos os resultados foram submetidos ao teste t à 5% de significância para a realização da análise estatística. As médias de produção de foram maiores para os tratamentos adubados com cama de frango e esterco, sendo de 3878,89 kg MSV.ha-1 e 3873,67 kg MSV.ha-1, respectivamente. Não foram observadas diferenças entre as recuperações aparentes do nitrogênio aplicado. As perdas por lixiviação de nitrato foram diferentes somente entre os ciclos, como consequência dos maiores índices de precipitação observados no terceiro ciclo amostrado, que apresentou média de -0,2.10-4 kg de NO3-.ha-1dia-1. Os valores de amônia volatilizada foram diferentes entre os ciclos e entre os tratamentos, sendo que no primeiro ciclo as maiores perdas foram atribuídas ao esterco, com 20,58% do nitrogênio aplicado. A cama de frango apresentou as maiores perdas de volatilização durante o segundo ciclo, com perda de 10,71% do nitrogênio aplicado, enquanto no terceiro ciclo a uréia apresentou a maior perda de nitrogênio, com 22,23% do nitrogênio volatilizado. As perdas por volatilização mais expressivas foram registradas até 60 horas após a aplicação das fontes. / The efficiency of nitrogen fertilization is one of the key elements to grass production. The knowledge of nitrogen losses within this practice associated with the application of alternative nitrogen sources provide efficient use and flexibility in choosing between nitrogen fertilizers. The objective of this study was to evaluate nitrate leaching, ammonium volatilization losses and apparent recovery of the applied nitrogen in elephant-grass pasture managed under high soil fertility. It was conducted at the Animal Science Department of ESALQ/USP, in Piraicaba - S.P. The statistical design was in complete randomized blocks, with four replicates and six treatments, which were the use of 100 kg N.ha-1 as urea, ammonium nitrate, dairy manure, chicken litter and ajifer. There were three cycles of evaluations, from November 2006 to February 2007, resulting in 300 kg N.ha-1 applied during the whole period. The results were statistically analysed by the t test with 5% significance. Chicken litter and dairy manure treatments provided the higher dry matter yields of 3878,89 DM.ha-1 and 3873,67 kg DM.ha-1, for each source respectively. Nitrate leaching losses were significant in the third cycle when -0,2.10-4 kg NO3-.ha-1.day-1 was lost. Ammonia volatilization was different between cycles and sources. In the first cycle the dairy manure resulted in higher losses of 26,42 kg N.ha-1. Chicken litter and urea lost 23,97 and 22,27 kg N.ha-1, respectively. In the second cycle urea presented the higher losses of 22,50, while dairy manure and chicken litter lost 6,01 and 15,88 kg N.ha-1. During the third cycle urea presented higher losses than , with 40,12 kg N.ha-1, dairy manure and chicken , which were 2,71 and 11,93 kg N.ha-1. Higher volatilization losses were observed until 60 hours after fertilization.

O presente experimento de laboratório foi realizado no Departamento de Ciência do Solo da ESALQ/USP, em Piracicaba, SP, com o objetivo de avaliar o efeito da presença de diferentes resíduos vegetais na superfície do solo sobre as perdas de amônia por volatilização decorrentes da aplicação de uréia em três doses. Foram utilizadas amostras da camada 0-0,20m de um Nitossolo Vermelho Eutroférrico do município de Piracicaba, SP. Os tratamentos constaram de arranjo fatorial com três repetições envolvendo quatro doses de uréia (0, 60, 120 e 180 mg dm-3 de N), aplicadas na superfície da terra, e quatro formas de cobertura da terra: sem cobertura e com cobertura constituída de fragmentos de folhas de plantas de milho, cana-de-açúcar e amendoim forrageiro, igualmente aplicados na superfície na quantidade de 29g de matéria seca por frasco (equivalente a 5 Mg ha-1). A volatilização de amônia foi avaliada em frascos de plástico de 1,6 L de capacidade, fechados, contendo 0,4 kg de terra umedecida e, para captar a amônia volatilizada, um disco de papel de filtro tratado com 1 mL de H2SO4 de concentração variando de 0,05 a 0,5 mol L-1. Esse disco era substituído diariamente, sendo o ácido remanescente no filtro exposto à amônia, titulado com NaOH 0,02 mol L-1 na presença de indicador bromocresol verde. Ao final do período experimental de 40 dias, amostras da camada superficial (0-0,05m) de terra dos frascos foram coletadas com amostrador especial e submetidas à determinação do pH em CaCl2 0,01 mol L-1. Os picos de máxima perda de amônia por volatilização ocorreram no 3º e no 12º dia após a aplicação da uréia, não havendo efeito dos resíduos culturais sobre a distribuição das perdas ao longo do tempo. As perdas de amônia aumentaram com o aumento da dose de uréia aplicada. Nas terras sem cobertura e naquelas contendo resíduos de milho e de amendoim forrageiro os aumentos foram mais expressivos para as doses menores (60 e 120 mg dm-3 de N-uréia), enquanto nas terras com restos de cana-de-açúcar os maiores aumentos ocorreram para a dose mais alta (180 mg dm-3 de N-uréia). A presença de restos de cultura de amendoim forrageiro na superfície do solo aumentou a quantidade de amônia volatilizada das terras tratadas ou não com uréia, enquanto a de restos de cultura de cana-de-açúcar reduziu a quantidade volatilizada. Os restos de cultura de milho exerceram pouca influência nas perdas de NH3 por volatilização. O pH da camada superficial das terras aumentou em mais de duas unidades com a aplicação de uréia e dos resíduos vegetais. / A laboratory experiment was carried out at the University of São Paulo, Piracicaba campus, Brazil, in order to evaluate how the presence of different plant residues on soil surface will affect ammonia volatilization losses from urea fertilizer applied on soil surface in three rates. Samples from 0-0.2m layer of a ferric Red Latosol located in Piracicaba, State of São Paulo, Brazil, were used in the study. Treatments consisted of a factorial arrangement with three replicates involving four rates of urea (0, 60, 120 and 180 mg dm-1 of N), applied at soil surface and four forms of soil cover: with no cover and with cover consisted of leaf fragments of corn, sugar-cane and peanut plants also applied on the surface at the rate of 29 g of dryed material per flask (equivalent to 5 Mg per hectare). Ammonia volatilization was measured in closed 1.6 L flasks containing 0.4 kg of moistened soil sample and, to capture NH3, a filter paper disk treated with 1 mL of H2SO4 of concentration varying from 0.05 to 0.5 mol L-1. The paper filter was substituted every day and the remaining acid in the exposed filter was titrated with NaOH 0.02 mol L-1 in the presence of bromocresol green. At the end of the experimental period of 40 days, samples of the surface layer (0-0.05 m) of the soil in the flasks were collected using a special sampler and subjected to determination of the pH in CaCl2 0.01 mol L-1. Maximum volatilization occurred at the 3rd and the 12th day of urea application and no influence was observed of the plant residues on the distribution of the losses during the experimental period. Ammonia losses increased with the rate of urea application. For the bare soil samples and for samples covered with corn and peanut residues, these increases were more evident when urea was applied at the smaller rates (60 and 120 mg dm-1 of urea-N), whereas for samples covered with sugar-cane residues, increases were higher when the higher rate (180 mg dm-1 of urea-N) was used. Covering the soil with peanut residues increased the amount of volatilized ammonia in the samples treated and not treated with urea, while covering with sugar-cane residues reduced the volatilization losses. Corn residues showed to have only small influence on ammonia loss. The pH at the surface of the soil samples increased more than two units as the result of urea and plant residues application.

O presente experimento de laboratório foi realizado no Departamento de Ciência do Solo da ESALQ/USP, em Piracicaba, SP, com o objetivo de avaliar o efeito da presença de diferentes resíduos vegetais na superfície do solo sobre as perdas de amônia por volatilização decorrentes da aplicação de uréia em três doses. Foram utilizadas amostras da camada 0-0,20m de um Nitossolo Vermelho Eutroférrico do município de Piracicaba, SP. Os tratamentos constaram de arranjo fatorial com três repetições envolvendo quatro doses de uréia (0, 60, 120 e 180 mg dm-3 de N), aplicadas na superfície da terra, e quatro formas de cobertura da terra: sem cobertura e com cobertura constituída de fragmentos de folhas de plantas de milho, cana-de-açúcar e amendoim forrageiro, igualmente aplicados na superfície na quantidade de 29g de matéria seca por frasco (equivalente a 5 Mg ha-1). A volatilização de amônia foi avaliada em frascos de plástico de 1,6 L de capacidade, fechados, contendo 0,4 kg de terra umedecida e, para captar a amônia volatilizada, um disco de papel de filtro tratado com 1 mL de H2SO4 de concentração variando de 0,05 a 0,5 mol L-1. Esse disco era substituído diariamente, sendo o ácido remanescente no filtro exposto à amônia, titulado com NaOH 0,02 mol L-1 na presença de indicador bromocresol verde. Ao final do período experimental de 40 dias, amostras da camada superficial (0-0,05m) de terra dos frascos foram coletadas com amostrador especial e submetidas à determinação do pH em CaCl2 0,01 mol L-1. Os picos de máxima perda de amônia por volatilização ocorreram no 3º e no 12º dia após a aplicação da uréia, não havendo efeito dos resíduos culturais sobre a distribuição das perdas ao longo do tempo. As perdas de amônia aumentaram com o aumento da dose de uréia aplicada. Nas terras sem cobertura e naquelas contendo resíduos de milho e de amendoim forrageiro os aumentos foram mais expressivos para as doses menores (60 e 120 mg dm-3 de N-uréia), enquanto nas terras com restos de cana-de-açúcar os maiores aumentos ocorreram para a dose mais alta (180 mg dm-3 de N-uréia). A presença de restos de cultura de amendoim forrageiro na superfície do solo aumentou a quantidade de amônia volatilizada das terras tratadas ou não com uréia, enquanto a de restos de cultura de cana-de-açúcar reduziu a quantidade volatilizada. Os restos de cultura de milho exerceram pouca influência nas perdas de NH3 por volatilização. O pH da camada superficial das terras aumentou em mais de duas unidades com a aplicação de uréia e dos resíduos vegetais. / A laboratory experiment was carried out at the University of São Paulo, Piracicaba campus, Brazil, in order to evaluate how the presence of different plant residues on soil surface will affect ammonia volatilization losses from urea fertilizer applied on soil surface in three rates. Samples from 0-0.2m layer of a ferric Red Latosol located in Piracicaba, State of São Paulo, Brazil, were used in the study. Treatments consisted of a factorial arrangement with three replicates involving four rates of urea (0, 60, 120 and 180 mg dm-1 of N), applied at soil surface and four forms of soil cover: with no cover and with cover consisted of leaf fragments of corn, sugar-cane and peanut plants also applied on the surface at the rate of 29 g of dryed material per flask (equivalent to 5 Mg per hectare). Ammonia volatilization was measured in closed 1.6 L flasks containing 0.4 kg of moistened soil sample and, to capture NH3, a filter paper disk treated with 1 mL of H2SO4 of concentration varying from 0.05 to 0.5 mol L-1. The paper filter was substituted every day and the remaining acid in the exposed filter was titrated with NaOH 0.02 mol L-1 in the presence of bromocresol green. At the end of the experimental period of 40 days, samples of the surface layer (0-0.05 m) of the soil in the flasks were collected using a special sampler and subjected to determination of the pH in CaCl2 0.01 mol L-1. Maximum volatilization occurred at the 3rd and the 12th day of urea application and no influence was observed of the plant residues on the distribution of the losses during the experimental period. Ammonia losses increased with the rate of urea application. For the bare soil samples and for samples covered with corn and peanut residues, these increases were more evident when urea was applied at the smaller rates (60 and 120 mg dm-1 of urea-N), whereas for samples covered with sugar-cane residues, increases were higher when the higher rate (180 mg dm-1 of urea-N) was used. Covering the soil with peanut residues increased the amount of volatilized ammonia in the samples treated and not treated with urea, while covering with sugar-cane residues reduced the volatilization losses. Corn residues showed to have only small influence on ammonia loss. The pH at the surface of the soil samples increased more than two units as the result of urea and plant residues application.

Unintentional nitrogen (N) loss from agroecosystems produces greenhouse gases, induces eutrophication, and is costly for farmers; therefore, adoption of conservation agricultural management practices, such as no-till and cover cropping, has increased. This study assessed N loss via leaching, NH3 volatilization, N2O emissions, and N retention in plant and soil pools of corn conservation agroecosystems across a year. Three systems were evaluated: 1) an unfertilized organic system with cover crops Vicia villosa, Triticum aestivum, or a mix of the two; 2) an organic system with a Vicia cover crop employing three fertilization schemes (0 N, organic N, or a cover crop N-credit approach); 3) a conventional system with a Triticum cover crop and three fertilization techniques (0 N, urea N, or organic N). During cover crop growth, species affected N leaching but gaseous emissions were low across all treatments. During corn growth, cover crop and fertilizer approach affected N loss. Fertilized treatments had greater N loss than unfertilized treatments, and fertilizer type affected gaseous fluxes temporally and in magnitude. Overall, increased N availability did not always indicate greater N loss or yield, suggesting that N conserving management techniques can be employed in conservation agriculture systems without sacrificing yield.

Submitted by JANAINA MATIAS PEREIRA DA SILVA null (jana.mps@hotmail.com) on 2016-04-29T12:35:20Z No. of bitstreams: 1 Janaina DISSERTAÇÃO FINAL fev com ficha.pdf: 495368 bytes, checksum: 8f0f99954b0a3ecb942b32b395479d4b (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-02T18:00:20Z (GMT) No. of bitstreams: 1 silva_jmp_me_bot.pdf: 495368 bytes, checksum: 8f0f99954b0a3ecb942b32b395479d4b (MD5) / Made available in DSpace on 2016-05-02T18:00:20Z (GMT). No. of bitstreams: 1 silva_jmp_me_bot.pdf: 495368 bytes, checksum: 8f0f99954b0a3ecb942b32b395479d4b (MD5) Previous issue date: 2016-02-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A cama de frango é um adubo orgânico cuja principal característica é a concentração de nitrogênio, porém, há uma alta taxa de volatilização de nitrogênio em forma de amônia. No presente estudo, foi possível avaliar a eficiência do gesso agrícola em diminuir as perdas de nitrogênio da cama de frango por volatilização e melhorar sua característica como fertilizante na adubação da cultura do milho. Os ensaios constituíram pela aplicação de gesso agrícola em cama de frangos de corte nos quais, foram empregados doses de 15%, 30% e 45% em relação ao volume de maravalha, e um tratamento controle sem adição de gesso. Durante todo o período de cria, nos três lotes consecutivos de frangos, foram coletadas amostras de amônia volatilizada por meio de sensor durante três períodos do dia a cada sete dias. Uma amostragem da cama foi coletada ao final de cada ciclo para análises químicas. Ao término da cria a cama foi retirada do galpão e aplicada como fertilizante em vasos para o cultivo do milho em casa de vegetação, mantendo os tratamentos inicias combinados com e sem a aplicação de 100mg de nitrogênio/kg da massa de solo, formando um esquema fatorial de quatro tratamentos com duas variáveis (4x2). Após 50 dias de cultivo foram coletadas amostras de solo para análises, observou-se que o gesso foi incapaz de controlar a volatilização de amônia, não diferindo nos teores de nitrogênio inorgânico. Portanto, os tratamentos não incrementaram eficiência em produção de matéria seca do milho, outrora, essas combinações entre cama de frango, gesso e nitrogênio, elevaram a concentração de fósforo e nitrogênio na raiz da cultura. / Poultry litter is organic fertilizer whose major characteristic is the nitrogen concentration, but, there is a high volatization nitrogen rate in the form ammonia. This study, was possible appreciate the phosphorgypsum efficiency to reduce nitrogen losses on poultry litter through volatilization and upgrade characteristic like a fertilizer in the cultivation corn. The testing considered in application phosphogypsum in poultry litter, were employed 15%, 30% and 45% doses compared to wood shaving volume, and control treatment without addition gypsum. While the period creates, three consecutive poultry lots, was collected samples volatilized ammonia by a sensor during three periods in the day each seven days. Was collected sampling bed in every final cycle to chemical analysis, finishing all cycle the bed was removed to be applied as fertilizer inside vase corn cultivation in house vegetation, keeping the treatments initial combination with and without application 100mg nitrogen / kg soil volume, constituted a factorial arrangement of four treatments with two variables (4x2). After 50 days cultivation was collected samples soil to analyze, it was observed that gypsum is unable to control ammonia volatization, not differing inorganic nitrogen. Therefore, treatments was not increase efficiency in production corn dry matter, in the other hand, this combinations between poultry litter, gypsum and nitrogen increased the concentration phosphorus and nitrogen in cultivation root.

Made available in DSpace on 2015-03-26T13:53:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-26 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The lower NH3 volatilization from urea combined with humicified organic material has been attributed to the formation and adsorption of NH4+ due the high potential acidity and CEC. In this context, an experiment was conducted to evaluate NH3 volatilization from grainy urea or coated with humic acids (HA) and humic substances (HS) synthesized from vegetable charcoal (VC). The synthesis of HA and HS was due to the oxidation from charcoal of eucalyptus with HNO3 4.4 mol L-1 boiled under reflux for 4 hours. The HS were obtained directly by filtration. For the HA and HS achievement, It was solubilized in NaOH 0.5 mol L-1 and the fraction of HA was the one that precipitated until acidification to pH 2.0. It was produced grainy urea and urea coated with 5, 10, 15 and 20 % HA or HS. For the granulation, mixtures of urea (p.a.) and HA or HS were fused in 137 ° C and dripped using a pipette on a metal plate. With the fast cooling of the drops, granules in the form of tablets (4 to 5 mm in diameter) were formed. The commercial grainy urea (1-2 mm) was coated with HA or humic substances, using vegetable oil to promote adhesion. Volatilization of NH3 was evaluated in the laboratory in a closed system with continuous air flow, where 100 mg of N-urea was applied to a 100 cm3 surface of a red-yellow Acrisol (<2 mm). The synthesis income was 327 g kg-1 of HA and 784 g kg-1 of humic substance. The acidity of the carboxylic and phenolic groups was estimated through adjusting multiparameter non-linear potentiometric titration curve and, together, corresponded to the CEC of the HA (4750 mmol c kg-1) and HS (4360 mmol c kg-1), which were 9.5 and 8.7 times higher than the VC. The carboxylic groups were predominant either in the VC as in HA and HS, but the HA had a higher content of carboxylic groups and lower content of phenolic groups than the HS. The presence of carboxylic groups was confirmed by the spectra in the infrared range, showing absorption of stretching and deformation, characteristic of C = O bond with 1703.74 and 1706.88 cm-1 waves to the HA and HS, respectively. The urea fusion did not change the N content, but they ranged on average from 36 to 42 % with the addition of 20 to 5 % HA or HS. The highest volatilization rate occurred between 37 and 41 h after application and this time was little influenced by the proportions of HA and HS. Without the addition of HA and HS, the urea in a tablet shape and the commercial grainy urea provided a total volatilization of 517.4 and 468.8 mg g-1 of N-NH3. The largest reductions in evaporation occur with grainy urea (44.5 %) and coated (28.7 %) with 15 and 20 % HA, respectively. In the grainy urea the proportions of HA and HS provided equivalent reduction in evaporation. / A menor volatilização de NH3 a partir da ureia combinada com material orgânico humificado tem sido atribuída à formação e à adsorção do NH4 + em razão da elevada acidez potencial e CTC. Neste contexto, foi conduzido um experimento para avaliar a volatilização de NH3 a partir da ureia granulada ou revestida com ácidos húmicos (AH) e substâncias húmicas (SH) sintetizadas de carvão vegetal (CV). A síntese dos AH e SH se deu pela oxidação do CV de eucalipto com HNO3 4,4 mol L-1 em ebulição sob refluxo por 4h. As SH foram obtidas diretamente por filtragem. Para obter os AH as SH foram solubilizadas em NaOH 0,5 mol L-1 e a fração AH foi aquela precipitada com a acidificação até pH 2,0. Foi produzida ureia granulada e ureia revestida com 5, 10, 15 e 20 % de AH ou SH. Para a granulação as misturas de ureia (p.a.) com AH ou SH foram fundidas a 137 °C e gotejadas com uma pipeta em uma placa metálica. Com o resfriamento rápido das gotas formaram-se grânulos na forma de pastilhas (4 a 5 mm de diâmetro). A ureia granulada comercial (1 a 2 mm) foi revestida com AH ou SH utilizando-se óleo vegetal para favorecer a aderência. A volatilização de NH3 foi avaliada em laboratório em um sistema fechado com fluxo contínuo de ar, onde 100 mg de N-ureia foi aplicada nas superfície de 100 cm3 de um Argissolo Vermelho- Amarelo (< 2 mm). O rendimento na síntese foi de 327 g kg-1 de AH e 784 g kg-1 de SH. A acidez dos grupos carboxílicos e fenólicos foi estimada por meio do ajuste multiparamétrico não linear da curva de titulação potenciométrica e, em conjunto, corresponderam à CTC dos AH (4.750 mmolc kg-1) e SH (4.360 mmolc kg-1), que foram 9,5 e 8,7 vezes maiores do que a do CV. Os grupos carboxílicos predominaram tanto no CV como nos AH e SH, porém os AH apresentaram maior teor de grupos carboxílicos e menor teor de grupos fenólicos do que as SH. A ocorrência dos grupos carboxílicos foi confirmada pelos espectros na faixa do infravermelho que evidenciaram absorção de estiramento e deformação característica da ligação C=O com 1.703,74 e 1.706,88 cm-1 ondas para os AH e SH, respectivamente. A fusão da ureia não alterou o teor de N, mas estes variaram, em média, de 36 a 42 % com a adição de 20 a 5 % de AH ou SH. A maior taxa de volatilização ocorreu entre 37 e 41 h após a aplicação e este tempo foi pouco influenciado pelas proporções de AH e SH. Sem a adição de AH ou SH a ureia na forma de pastilha e a ureia granulada comercial proporcionaram volatilização total de 517,4 e 468,8 mg g-1 de N-NH3. As maiores reduções na volatilização ocorreram com a ureia granulada (44,5 %) e revestida (28,7 %) com 15 e 20 % de AH, respectivamente. Na ureia granulada as proporções de AH e de SH proporcionaram redução equivalente na volatilização.