- A soil scientist in soil fertility and plant nutrition, soil management, Biological dinitrogen fixation, soil C sequastration and nutrient cicling.edit
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Exsudação de N pelo sistema radicular. Técnicas de marcação de plantas com 15N para determinação de N subterrâneo.bitstream/CNPAB-2010/32106/1/doc186.pd
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bitstream/item/218709/1/desempenho-soja-Norte-fluminense.pd
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bitstream/item/221809/1/capitulo-mudancas-ambientais-sequestro-de-carbono.pd
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Fixação biológica de nitrogênio na cultura de cana-de-açúcar. Balanço de N-total do sistema solo-planta. FBN pelo balanço de N-total do sistema solo-planta.bitstream/CNPAB-2010/32100/1/doc179.pd
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articles: 1 Urquiaga, S.; Alves, B. J. R.; Boddey, R M Constraints to Crop Production on the Acid soils of Brazil and the role of Zero Tillage in the Promotion of Sustainable Agriculture. In: WORKSHOP ON ́THE DEVELOPMENT OF MANAGEMENT... more
articles: 1 Urquiaga, S.; Alves, B. J. R.; Boddey, R M Constraints to Crop Production on the Acid soils of Brazil and the role of Zero Tillage in the Promotion of Sustainable Agriculture. In: WORKSHOP ON ́THE DEVELOPMENT OF MANAGEMENT PRACTICES FOR SUSTAINABLE CROP PRODUCTION SYSTEM ON THE TROPICAL ACIDS SOILS THROUGH THE USE OF NUCLEAR AND RELATED TECHNIQUES`, Workshop on ́The Development of Management Practices for Sustainable Crop Production System on the Tropical Acids Soils Through the use of Nuclear and Related techniques”. Vienna, Austria: IAEA, 2000. 2 Alves, B. J. R., L. Zotarelli, R. M. Boddey, And S. Urquiaga. 2002. Soybean Benefit to a subsequent Wheat Crop in a Cropping System Under Zero Tillage. Nuclear Techniques in
Descricao e caracterizacao da area experimental. Amostragem e preparo das amostras de solo. Calculos do estoque de carbono e nitrogenio no perfil do solo sob os tratamentos. Estimativa da proporcao de carbono do solo derivado da vegetacao... more
Descricao e caracterizacao da area experimental. Amostragem e preparo das amostras de solo. Calculos do estoque de carbono e nitrogenio no perfil do solo sob os tratamentos. Estimativa da proporcao de carbono do solo derivado da vegetacao nativa original. Analise estatistica. Fertilidade e densidade do solo na area sob vegetacao nativa e sob os tratamentos de manejo do solo e rotacao de culturas. Teores de carbono orgânico total e nitrogenio total do solo. Estoques de carbono e nitrogenio no solo sob diferentes tratamentos de preparo e rotacao de culturas. Abundância natural de 13C no perfil do solo. Estimativa da proporcao de carbono da materia orgânica do solo derivada da vegetacao nativa. O sistema plantio direto (PD), utilizado inicialmente para minimizar a erosao do solo provocada pelo preparo convencional (PC), revela-se como de grande potencial para incrementar a materia orgânica do solo (MOS), principalmente quando praticado com plantas para adubacao verde em rotacao de cult...
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Soils harbour diverse soil faunaand a wide range of soil microorganisms. These fauna and microorganisms directly contribute to soil greenhouse gas (GHG) fluxes via their respiratory and metabolic activities and indirectly by changing the... more
Soils harbour diverse soil faunaand a wide range of soil microorganisms. These fauna and microorganisms directly contribute to soil greenhouse gas (GHG) fluxes via their respiratory and metabolic activities and indirectly by changing the physical, chemical and biological properties of soils through bioturbation, fragmentation and redistribution of plant residues, defecation, soil aggregate formation, herbivory, and grazing on microorganisms and fungi. Based on recent results, the methods and results found in relation to fauna as well as from fungi and plants are presented. The approaches are outlined, and the significance of these hitherto ignored fluxes is discussed.
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A introducao de leguminosas em pastagens de gramineas, na forma de consorcio, tem sido apresentada como uma estrategia para repor as quantidades de N que se tornam indisponiveis para as gramineas ao longo dos anos. O efeito positivo desta... more
A introducao de leguminosas em pastagens de gramineas, na forma de consorcio, tem sido apresentada como uma estrategia para repor as quantidades de N que se tornam indisponiveis para as gramineas ao longo dos anos. O efeito positivo desta pratica para o ganho de producao animal e conhecido porem, ainda sao escassos os resultados que demonstrem que a leguminosa tambem favoreca a um aumento da longevidade da pastagem. Neste trabalho, comparou-se uma pastagem de Brachiaria ruziziensis consorciada com Srylosanthes guianensis com outra de B. ruziziensis em monocultura, com base em parâmetros da propria pastagem e de producao animal. Os resultados mostraram que a pastagem consorciada permitiu um maior ganho de peso animal por area e um continuo ganho de peso dos animais durante todo o periodo de avaliacao. A producao de forragem da pastagem consorciada superou em cerca de 4 t/ha a pastagem de graminea durante o periodo avaliado (abril/97 a outubro/97), o que aparentemente foi resultado de...
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Tratamento e delineamento experimental. Producao de materia seca e N-total acumulado pelas leguminosas. Decomposicao dos residuos derivados dos adubos verdes. Producao de materia seca de cana-de-acucar. Producao de fitomassa das... more
Tratamento e delineamento experimental. Producao de materia seca e N-total acumulado pelas leguminosas. Decomposicao dos residuos derivados dos adubos verdes. Producao de materia seca de cana-de-acucar. Producao de fitomassa das leguminosas e N-total acumulado. taxa de decomposicao de talos e folhas de plantas de leguminosas utilizadas como adubacao verde. Producao de materia seca e N-total acumulado pela cultura de cana-de-acucar.
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Efeito estufa. Interferencia e previsoes sobre o efeito estufa. O protocolo de Kyoto e o mecanismo de desenvolvimento limpo. Sequestro de carbono em ecossistemas terrestres. O caso do eucalipto. O caso do dende. O caso da cana-de-acucar.... more
Efeito estufa. Interferencia e previsoes sobre o efeito estufa. O protocolo de Kyoto e o mecanismo de desenvolvimento limpo. Sequestro de carbono em ecossistemas terrestres. O caso do eucalipto. O caso do dende. O caso da cana-de-acucar. Importância da FBN para o sequestro de carbono. Estimativas do sequestro de C na cultura de cana-de-acucar. O Brasil e as emissoes de gases do efeito estufa.
Research Interests: Chemistry, Carbono, Eucalipto, Dendê, C, and 3 moreCana de Açúcar, Fixação biológica de nitrogênio, and FBN
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Abstract The effects of commercial cultivars of Brachiaria decumbens , B. humidicola , and B. brizantha on nitrogen mineralization and nitrification were examined in a Dark Red Latosol from the Cerrados region of Central Brazil. B.... more
Abstract The effects of commercial cultivars of Brachiaria decumbens , B. humidicola , and B. brizantha on nitrogen mineralization and nitrification were examined in a Dark Red Latosol from the Cerrados region of Central Brazil. B. decumbens responded most rapidly to the addition of fertilizer N. B. brizantha also absorbed the fertilizer N rapidly but grew more slowly. By contrast, B. humidicola showed a slower response to the fertilizer addition, both in N uptake and growth. The concentrations of mineral N in the soil under both B. decumbens and B. brizantha indicated that most of the fertilizer N remaining in the soil was quickly immobilized, as also indicated by the results of incubated soil samples. On the other hand, the soil under B. humidicola showed strong mineralization of native organic N between three and six days after the addition of N in the presence of the plants, but not during the incubation. In this species there was also a clear indication of early nitrification, whereas in the soil under the other two species the build up of the nitrifier population seemed to be delayed. It is concluded that the species studied had different rates of N uptake and assimilation and stimulated microorganisms differently in their rhizosphere, which lead to contrasting transformations on the soil mineral N pool. The observed patterns of mineralization/immobilization and nitrification changed so quickly that analysis of the effects of plants on soil N transformations based on a few harvests or over long time intervals could be misleading.
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Epigeous termite mounds are frequently observed in pasture areas, but the processes regulating their population dynamics are poorly known. This study evaluated epigeous termite mounds in cultivated grasslands used as pastures, assessing... more
Epigeous termite mounds are frequently observed in pasture areas, but the processes regulating their population dynamics are poorly known. This study evaluated epigeous termite mounds in cultivated grasslands used as pastures, assessing their spatial distribution by means of geostatistics and evaluating their vitality. The study was conducted in the Cerrado biome in the municipality of Rio Brilhante, Mato Grosso do Sul, Brazil. In two pasture areas (Pasture 1 and Pasture 2), epigeous mounds (nests) were georeferenced and analyzed for height, circumference and vitality (inhabited or not). The area occupied by the mounds was calculated and termite specimens were collected for taxonomic identification. The spatial distribution pattern of the mounds was analyzed with geostatistical procedures. In both pasture areas, all epigeous mounds were built by the same species, Cornitermes cumulans. The mean number of mounds per hectare was 68 in Pasture 1 and 127 in Pasture 2, representing 0.4 an...
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In 1998, Fisher et al. attempted to draw together published and anecdotal information to answer some of the questions raised by the fi ndings of Fisher et al. (1994; 1995), that introduced pas- tures of African grasses on the eastern... more
In 1998, Fisher et al. attempted to draw together published and anecdotal information to answer some of the questions raised by the fi ndings of Fisher et al. (1994; 1995), that introduced pas- tures of African grasses on the eastern plains of Colombia accumulated large amounts of C in the soil. This review synthesises the work in both Colombia and Brazil over the last 7 years that answers some of the questions raised and spec- ulations made by Fisher et al. (1998). The most important studies have shown that the rate at which litter decays at the soil surface has been grossly underestimated in the past. As a conse- quence, net aerial primary productivity (NAPP) was shown to be 33.3-33.5 t/ha/yr in well man- aged pastures of introduced grasses without either a legume component or N fertiliser. While data for soil C vary according to the past his- tory and states of the pasture, well managed pas- tures do accumulate C in the soil to levels above that under the native grassland vegetat...
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Continuous sugarcane (Saccharum spp.) culture in Brazil, with low N inputs and almost total removal of plant biomass at each harvest, has not depleted soil N reserves. This, and high numbers of N2‐fixing bacteria associated with the... more
Continuous sugarcane (Saccharum spp.) culture in Brazil, with low N inputs and almost total removal of plant biomass at each harvest, has not depleted soil N reserves. This, and high numbers of N2‐fixing bacteria associated with the plants, suggests that the crop may be obtaining considerable N from biological nitrogen fixation (BNF). This 3‐yr study assessed the importance of such contributions to three sugarcane species (S. officinarum L., S. barberi Jesw., and S. spontaneum L.), and seven commercial Brazilian hybrids. The plants were grown in a concrete tank containing 15N‐labeled soil in order to use 15N isotope dilution to estimate the BNF contributions. A grass, Brachiaria arrecta (cv. IRI 442), was included as a non‐N2‐fixing control. All aerial tissue was harvested annually, and the roots and stem bases were removed at the end of the experiment. For all 3 yr, the commercial hybrids and the S. spontaneum cultivar (Krakatau) accumulated more N at significantly lower 15N enrich...
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... PM Chalk Corresponding Author Contact Information , a , E-mail The Corresponding Author , R. de F. Souza a , S. Urquiaga a , BJR ... successfully employed as a means to generate differences in indigenous AM colonization potential... more
... PM Chalk Corresponding Author Contact Information , a , E-mail The Corresponding Author , R. de F. Souza a , S. Urquiaga a , BJR ... successfully employed as a means to generate differences in indigenous AM colonization potential (Goss and de Varennes, 2002; Antunes et al ...
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SUMMARY A pot experiment was conducted under glasshouse conditions to investigate the effect of inoculation with four arbuscular mycorrhizal (AM) fungi (Glomus clarum, G. etunicatum, G. manihotis, Gigaspora margarita), either individually... more
SUMMARY A pot experiment was conducted under glasshouse conditions to investigate the effect of inoculation with four arbuscular mycorrhizal (AM) fungi (Glomus clarum, G. etunicatum, G. manihotis, Gigaspora margarita), either individually or in a mixture, and with Rhizobium leguminosarum biovar phaseoli, on the growth, mineral nutrition, and contribution of biologically fixed N2, to three nodulating bean (Phaseolus vulgaris) varieties (Carioca, Negro Argel and Rio Tibagi). The '5N isotope dilution technique and three control crops (non-nodulating bean, Panicum maximum and sorghum) were used to quantify the contribution of N2 fixation. There were significant differences between the capacity of the different AM fungi to infect and colonize the roots of the different bean varieties. Inoculation with AM fungi significantly increased production of dry matter by 8-23 % and the concentration of P in plants by 160-335 %. A strongly positive correlation of % root colonization by AM fungi and plant P concentration and accumulation was observed which suggests that the observed inoculation responses were a result of improved P acquisition by the mycorrhizal roots. N derived from the atmosphere increased significantly with AM fungi inoculation, with Carioca showing the best response, followed by Negro Argel and Rio Tibagi, thereby showing the indirect and positive effect of AM fungi inoculation on the N2-fixing association between Rhizobium and Phaseolus vulgaris.
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Foram feitas medidas de erosão do solo com a técnia de Cs. Utiliza a equação universal de perda de solo para estimar a erosão, o que resultou em dados superestimados para o local do estudo. Mostrou que o balanço de N na cultura do café... more
Foram feitas medidas de erosão do solo com a técnia de Cs. Utiliza a equação universal de perda de solo para estimar a erosão, o que resultou em dados superestimados para o local do estudo. Mostrou que o balanço de N na cultura do café foi de -39kg N ha-1ano-1. O café apresenta balanço negativo apenas para nitrogênio.bitstream/CNPAB-2010/35839/1/bot037.pd
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A perda de N por volatilização de N-NH3 é um processo que contribui para a baixa eficiência de fertilizantes nitrogenados em sistemas agrícolas. Assim, a quantificação do N perdido por essa via contribui para melhor planejamento do manejo... more
A perda de N por volatilização de N-NH3 é um processo que contribui para a baixa eficiência de fertilizantes nitrogenados em sistemas agrícolas. Assim, a quantificação do N perdido por essa via contribui para melhor planejamento do manejo dos fertilizantes e para o desenvolvimento de técnicas que visem impedir ou reduzir a volatilização do NNH3. Na literatura, são encontrados estudos que descrevem câmaras coletoras de N-NH3, entretanto, a maior limitação dessas câmaras é a baixa eficiência de recuperação do N volatilizado (normalmente menor do que 20%), e são laboriosas, o que dificulta a utilização de um número de repetições adequado a esses estudos. Dessa forma, modificou-se uma câmara coletora de N-NH3 (Marsola et al, resumo da Fertbio, Santa Maria, RS, 2000) visando aumentar sua eficiência para mais de 50%, em condições de altas taxas de volatilização. Material e Métodos
Avaliou fluxos de energia associados às atividades agricolas de produção das culturas de feijão e sorgo granífero, em período de entressafras, em sistema lavoua-pecuária em duas áreas distintas do cerrado. Enquanto o sorgo resulta em... more
Avaliou fluxos de energia associados às atividades agricolas de produção das culturas de feijão e sorgo granífero, em período de entressafras, em sistema lavoua-pecuária em duas áreas distintas do cerrado. Enquanto o sorgo resulta em saldo energético positivo em 21 GJ por hectare, o feijão propicia uma saldo de 4,3 GJ.bitstream/CNPAB-2010/35841/1/bot038.pd
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bitstream/item/227287/1/Resposta-de-diferentes-genotipos-de-Brachiaria-a-inoculacao.pd
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The rapidly changing global climate due to increased emission of anthropogenic greenhouse gases (GHGs) is leading to an increased occurrence of extreme weather events such as droughts, floods, and heatwaves. The three major GHGs are... more
The rapidly changing global climate due to increased emission of anthropogenic greenhouse gases (GHGs) is leading to an increased occurrence of extreme weather events such as droughts, floods, and heatwaves. The three major GHGs are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The major natural sources of CO2 include ocean–atmosphere exchange, respiration of animals, soils (microbial respiration) and plants, and volcanic eruption; while the anthropogenic sources include burning of fossil fuel (coal, natural gas, and oil), deforestation, and the cultivation of land that increases the decomposition of soil organic matter and crop and animal residues. Natural sources of CH4 emission include wetlands, termite activities, and oceans. Paddy fields used for rice production, livestock production systems (enteric emission from ruminants), landfills, and the production and use of fossil fuels are the main anthropogenic sources of CH4. Nitrous oxide, in addition to being a maj...
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os objetivos deste projeto sao: 1. Quantificar a contribuicao da FBN para as leguminosas e estimar a eficiencia do uso do nitrogenio e o balanco total de N derivado de leguminosas para adubacao verde; 2. Avaliar as perdas de N como NH3 e... more
os objetivos deste projeto sao: 1. Quantificar a contribuicao da FBN para as leguminosas e estimar a eficiencia do uso do nitrogenio e o balanco total de N derivado de leguminosas para adubacao verde; 2. Avaliar as perdas de N como NH3 e N2O derivados do uso de leguminosas para adubacao verde.
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A preocupacao com o aumento da concentracao de gases de efeito estufa (GEE - CO2, CH4 e N2O) na atmosfera fez com que a comunidade cientifica quantificasse a emissao destes pelas diversas atividades antropicas, para melhor entendimento do... more
A preocupacao com o aumento da concentracao de gases de efeito estufa (GEE - CO2, CH4 e N2O) na atmosfera fez com que a comunidade cientifica quantificasse a emissao destes pelas diversas atividades antropicas, para melhor entendimento do impacto de cada uma neste processo. Nesses levantamentos, a atividade agropecuaria mundial e considerada como responsavel por 25% dos GEE emitidos no planeta (IPCC, 2001), e esta percentagem tambem e a mesma observada no setor agropecuario brasileiro. Os solos representam o terceiro maior compartimento de carbono (C) terrestre, por isso sao crescentes os esforcos em identificar praticas agropecuarias que promovam o acumulo ou a manutencao da materia orgânica do solo (MOS). No entanto, estudos sobre a dinâmica deste elemento sao realizados, geralmente, sem levar em consideracao a sua interacao com outros nutrientes. Deve-se considerar que no solo, o C encontra-se em forma orgânica, formando compostos de natureza variavel.
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Fluxo a partir da câmara estatica fechada e amostragem de gases do perfil do solo; Estimativa da difusividade; Calculo do fluxo e producao de N2O pela tecnica de concentracao no perfil do solo; Analises estatisticas. 0 objetivo do... more
Fluxo a partir da câmara estatica fechada e amostragem de gases do perfil do solo; Estimativa da difusividade; Calculo do fluxo e producao de N2O pela tecnica de concentracao no perfil do solo; Analises estatisticas. 0 objetivo do presente trabalho foi testar um novo metodo para avaliar a difusividade de gases do solo para estudos com N2O, baseado em medidas dos fluxos de CO2 para a atmosfera e de concentray80 de CO2 no perfil do solo. A hip6tese foi a de que 0 fluxo de N2O, calculado com as concentracoes de N20 no solo e difusividade, nao deveria ser diferente do fluxo de N20 estimado por uma câmara estatica fechada. 0 estudo foi feito em condicoes controladas, em um cilindro de 1 m de diâmetro x 0,5 m de altura, preenchido ate 0,3 m com solo seco ao ar e peneirado, com peneira de 2 mm. Um sistema para amostragem de gases foi montado nas profundidades de 5 e 15 cm. Uma câmara estatica foi montada sobre 0 mesmo ponto para avaliacao de fluxo de gas. As amostras de gases nas diferente...
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This study aimed to evaluate the production components of aboveground and total root stock biomass of Brachiaria pastures of different ages after renovation. Three B.brizantha pastures, with one, seven, and nine years after renovation... more
This study aimed to evaluate the production components of aboveground and total root stock biomass of Brachiaria pastures of different ages after renovation. Three B.brizantha pastures, with one, seven, and nine years after renovation through the Barreirao system, and one B. decumbens pasture twenty years after traditional renovation were evaluated. The areas were located at Goiânia, Brazil (16o35'12";S, 49o21'14";W, 730 m). The one year after renovation pasture showed the highest productivity, 197% higher than the twenty year after renovation pasture. With increasing pasture renovation age, there was a production and regrowth rate decrease due to the degradation process. This aspect may be observed in the root system development, since the total root productivity to 100 cm depth was reduced as pasture age increased, with 9.14 Mg ha-1, 4.87 Mg ha-1, and 2.90 Mg ha-1 for pastures of seven, nine, and twenty years after renovation, respectively. The one year pasture d...
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Research Interests: Environmental Science, Agronomy, Corn, Fertilizer, Ammonia, and 5 moreFertilizers, Adubação, Ammonium Sulfate, Adubo, and Milho
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ABSTRACT