A fixacao biologica de nitrogenio (FBN) e capaz de suprir toda demanda de nitrogenio da soja. A r... more A fixacao biologica de nitrogenio (FBN) e capaz de suprir toda demanda de nitrogenio da soja. A relacao simbiotica mais importante e com B. japonicum e B. elkanii. O objetivo foi avaliar a FBN na soja cultivar BRS 133 inoculada com 4 estirpes de Bradyrhizobium usando inoculante turfoso. O delineamento foi inteiramente casualizado com seis repeticoes. Os tratamentos foram soja inoculada com estirpes de B. japonicum (estirpes USAD110, CPAC15 e CPAC 7), B. elkanii (estirpe 29 W) e sorgo como testemunha. Aos 70 dias apos o plantio procedeu-se com a colheita da parte aerea e raizes das plantas as quais foram secas a 65 o C para determinar a materia seca (MS). As amostras foram processadas em moinho de rolagem ate formar po. Foi determinado o nitrogenio total (N) por meio de digestao Kjeldahl, e a razao isotopica de 15 N/ 14 N pelo metodo de Dumas em analisador automatico de C e N, acoplado a espectrometro de massas. Nao houve diferenca significativa em MS na parte aerea e planta inteira,...
This study evaluated soil parameters involved in ammonia (NH3) fluxes from livestock excreta and ... more This study evaluated soil parameters involved in ammonia (NH3) fluxes from livestock excreta and urea fertilizer. Treatments were distributed in a randomized block design, with five replicates. Treatments included application of 1) urine; 2) dung; or 3) urea fertilizer (50 kg N ha-1) on palisadegrass pasture (Brachiaria brizantha cv. Marandu). Excreta was collected from crossbred heifers grazing palisadegrass pastures. One soil background treatment without excreta or urea was included for the measurement of NH3 fluxes. Treatments were applied in May/2017, April/2018, and Jul/2018. One liter of urine, 1.6 kg of dung, and 2.67 g of urea fertilizer were added inside the chamber according to treatment. Ammonia flux was evaluated using a semi-opened free static chamber and N determination by steam distillation. The extracted solution of fresh soil was analyzed in spectrophotometer. Pearson’s correlation and linear regression analyses were run to identify which soil parameters explained N...
Few options have been found to mitigate nitrous oxide (N2O) emissions in grazing systems, which r... more Few options have been found to mitigate nitrous oxide (N2O) emissions in grazing systems, which requires attention, by the researches. The aim of this study was to determine N2O emissions from excreta of cattle grazed in Marandu-grass pastures (Brachiaria brizantha cv. Marandu) with different sources of nitrogen. The experiment consisted of two factors (pasture management and excreta type) in a randomized complete block design, with 5 replicates. The pastures were: 1) CONTROL: Marandu-grass pastures without nitrogen or legume; 2) FERT: Marandu-grass pastures fertilized with nitrogen (150 kg N haArachis pintoi cv. Amarillo). The excreta types were dung (1.6 kg/ treatment) and urine (1.0 L/ treatment) from heifers (353.1 ± 24.1 kg BW) grazing in the pastures. Static chambers were used to evaluate N2O emissions, which were determined by gas chromatography (electron capture detector), and were integrated over time, to calculate the cumulative emissions and the amount of nitrogen lost as N2O. Posteriorly, ANOVA was performed and the Tukey’s test was ran to determine differences among means. Dung emissions of N2O totaled 1151, 579 and 245 µg N-N2O mP = 0.0052). Urine emissions of N2O were 273, 347 and 275 µg N-N2O m2O emission factor differed between excreta type and was 2.2 times greater for dung than for urine (P = 0.038). For dung, the emission factor (EF) varied from 0.15 to 0.83% N-applied and for urine ranged 0.16% N-applied emitted as N2O. The greatest emissions were observed for FERT. Excreta affected N2O emissions, and in all cases, it was much lower than IPCC default Tier 1 emission factor.
Ammonia (NH3) is a large source of environmental contamination from nitrogen usage. The objective... more Ammonia (NH3) is a large source of environmental contamination from nitrogen usage. The objective of this study was to evaluate NH3 losses from urine and dung of cattle grazed in Marandu-grass pastures (Brachiaria brizantha cv. Marandu) with different sources of nitrogen. The experiment consisted of two factors (pasture management and excreta type) in a randomized complete block design, with 5 replicates. The pastures were: 1) CONTROL: Marandu-grass pastures without nitrogen or legume; 2) FERT: Marandu-grass pastures fertilized with nitrogen (150 kg N ha-1 year-1); 3) MIXED: Marandu-grass pastures intercropped with Pinto peanut (Arachis pintoi cv. Amarillo). The excreta types were dung (1.6 kg/ treatment) and urine (1.0 L/ treatment) from heifers (353.1 ± 24.1 kg BW) grazing in the pastures. Ammonia volatilization was evaluated using semi-opened free static chamber and nitrogen determination by steam distillation. Sampling were performed on 1, 3, 5, 9, 14 and 21 d after treatments being applied to the area. ANOVA was performed for total ammonia volatilized; when differences were observed among means, they were compared using the LSD test. For dung, NH3 losses differed among pasture treatments (P = 0.046). Volatilization losses was greater for FERT pastures (1.04% of applied N) compared with CONTROL (0.83% of applied N) and MIXED (0.81% of applied N) pastures. No differences were observed for urine among treatments for FERT (3.69 of applied N), MIXED (3.63 of applied N) and CONTROL (2.78 of applied N). The NH3 emission factor differed between excreta type (P < 0.0001). Urine averaged 3.40% and dung 0.89% of volatilized N-applied. Urine was the main source of ammonia volatilization, and all estimates of volatilization losses were among the lowest reported in the literature.
Mircen Journal of Applied Microbiology and Biotechnology, 1987
... experienced. The distillates are titrated against a sulphuric acid solution (0.05-0.25 N), th... more ... experienced. The distillates are titrated against a sulphuric acid solution (0.05-0.25 N), this acid being standardized by titration against a solution of tris (hydroxymethyl) methylamine (THAM) as suggested by Keeney & Nelson (1982). ...
In a paper published recently in this Journal a new equation was presented for the calculation of... more In a paper published recently in this Journal a new equation was presented for the calculation of the proportion of plant nitrogen derived from plant-associated biological nitrogen fixation (BNF) using the ‘A-value’ technique. To apply this technique it is assumed that the specific availability (‘A-value’) of soil N is constant regardless of the quantity of added labelled N fertilizer. The
In the estimation of the contribution of biological nitrogen fixation (BNF) to plant nutrition ma... more In the estimation of the contribution of biological nitrogen fixation (BNF) to plant nutrition many authors have compared the estimates derived from the15N-isotope-dilution technique with those derived from the total N-difference technique. In this paper we show that agreement of these two estimates is mathematically inevitable when the recovery of labelled nitrogen (%FUE) by the “N2-fixing” (test) and control plants
Biological nitrogen fixation (BNF) associated with trees and shrubs plays a major role in the fun... more Biological nitrogen fixation (BNF) associated with trees and shrubs plays a major role in the functioning of many ecosystems, from natural woodlands to plantations and agroforestry systems, but it is surprisingly difficult to quantify the amounts of N2 fixed. Some of the problems involved in measuring N2 fixation by woody perennials include: (a) diversity in occurrence, and large plant-to-plant variation
A introducao de leguminosas em pastagens de gramineas, na forma de consorcio, tem sido apresentad... 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...
Resumo A cultura de capim elefante (Pennisetum purpureum Schum.) é altamente eficiente na fixação... more Resumo A cultura de capim elefante (Pennisetum purpureum Schum.) é altamente eficiente na fixação de CO2 (gás carbônico) atmosférico durante o processo de fotossíntese para a produção de biomassa vegetal. Por ser uma espécie de rápido crescimento, a biomassa de capim-...
A fixacao biologica de nitrogenio (FBN) e capaz de suprir toda demanda de nitrogenio da soja. A r... more A fixacao biologica de nitrogenio (FBN) e capaz de suprir toda demanda de nitrogenio da soja. A relacao simbiotica mais importante e com B. japonicum e B. elkanii. O objetivo foi avaliar a FBN na soja cultivar BRS 133 inoculada com 4 estirpes de Bradyrhizobium usando inoculante turfoso. O delineamento foi inteiramente casualizado com seis repeticoes. Os tratamentos foram soja inoculada com estirpes de B. japonicum (estirpes USAD110, CPAC15 e CPAC 7), B. elkanii (estirpe 29 W) e sorgo como testemunha. Aos 70 dias apos o plantio procedeu-se com a colheita da parte aerea e raizes das plantas as quais foram secas a 65 o C para determinar a materia seca (MS). As amostras foram processadas em moinho de rolagem ate formar po. Foi determinado o nitrogenio total (N) por meio de digestao Kjeldahl, e a razao isotopica de 15 N/ 14 N pelo metodo de Dumas em analisador automatico de C e N, acoplado a espectrometro de massas. Nao houve diferenca significativa em MS na parte aerea e planta inteira,...
This study evaluated soil parameters involved in ammonia (NH3) fluxes from livestock excreta and ... more This study evaluated soil parameters involved in ammonia (NH3) fluxes from livestock excreta and urea fertilizer. Treatments were distributed in a randomized block design, with five replicates. Treatments included application of 1) urine; 2) dung; or 3) urea fertilizer (50 kg N ha-1) on palisadegrass pasture (Brachiaria brizantha cv. Marandu). Excreta was collected from crossbred heifers grazing palisadegrass pastures. One soil background treatment without excreta or urea was included for the measurement of NH3 fluxes. Treatments were applied in May/2017, April/2018, and Jul/2018. One liter of urine, 1.6 kg of dung, and 2.67 g of urea fertilizer were added inside the chamber according to treatment. Ammonia flux was evaluated using a semi-opened free static chamber and N determination by steam distillation. The extracted solution of fresh soil was analyzed in spectrophotometer. Pearson’s correlation and linear regression analyses were run to identify which soil parameters explained N...
Few options have been found to mitigate nitrous oxide (N2O) emissions in grazing systems, which r... more Few options have been found to mitigate nitrous oxide (N2O) emissions in grazing systems, which requires attention, by the researches. The aim of this study was to determine N2O emissions from excreta of cattle grazed in Marandu-grass pastures (Brachiaria brizantha cv. Marandu) with different sources of nitrogen. The experiment consisted of two factors (pasture management and excreta type) in a randomized complete block design, with 5 replicates. The pastures were: 1) CONTROL: Marandu-grass pastures without nitrogen or legume; 2) FERT: Marandu-grass pastures fertilized with nitrogen (150 kg N haArachis pintoi cv. Amarillo). The excreta types were dung (1.6 kg/ treatment) and urine (1.0 L/ treatment) from heifers (353.1 ± 24.1 kg BW) grazing in the pastures. Static chambers were used to evaluate N2O emissions, which were determined by gas chromatography (electron capture detector), and were integrated over time, to calculate the cumulative emissions and the amount of nitrogen lost as N2O. Posteriorly, ANOVA was performed and the Tukey’s test was ran to determine differences among means. Dung emissions of N2O totaled 1151, 579 and 245 µg N-N2O mP = 0.0052). Urine emissions of N2O were 273, 347 and 275 µg N-N2O m2O emission factor differed between excreta type and was 2.2 times greater for dung than for urine (P = 0.038). For dung, the emission factor (EF) varied from 0.15 to 0.83% N-applied and for urine ranged 0.16% N-applied emitted as N2O. The greatest emissions were observed for FERT. Excreta affected N2O emissions, and in all cases, it was much lower than IPCC default Tier 1 emission factor.
Ammonia (NH3) is a large source of environmental contamination from nitrogen usage. The objective... more Ammonia (NH3) is a large source of environmental contamination from nitrogen usage. The objective of this study was to evaluate NH3 losses from urine and dung of cattle grazed in Marandu-grass pastures (Brachiaria brizantha cv. Marandu) with different sources of nitrogen. The experiment consisted of two factors (pasture management and excreta type) in a randomized complete block design, with 5 replicates. The pastures were: 1) CONTROL: Marandu-grass pastures without nitrogen or legume; 2) FERT: Marandu-grass pastures fertilized with nitrogen (150 kg N ha-1 year-1); 3) MIXED: Marandu-grass pastures intercropped with Pinto peanut (Arachis pintoi cv. Amarillo). The excreta types were dung (1.6 kg/ treatment) and urine (1.0 L/ treatment) from heifers (353.1 ± 24.1 kg BW) grazing in the pastures. Ammonia volatilization was evaluated using semi-opened free static chamber and nitrogen determination by steam distillation. Sampling were performed on 1, 3, 5, 9, 14 and 21 d after treatments being applied to the area. ANOVA was performed for total ammonia volatilized; when differences were observed among means, they were compared using the LSD test. For dung, NH3 losses differed among pasture treatments (P = 0.046). Volatilization losses was greater for FERT pastures (1.04% of applied N) compared with CONTROL (0.83% of applied N) and MIXED (0.81% of applied N) pastures. No differences were observed for urine among treatments for FERT (3.69 of applied N), MIXED (3.63 of applied N) and CONTROL (2.78 of applied N). The NH3 emission factor differed between excreta type (P < 0.0001). Urine averaged 3.40% and dung 0.89% of volatilized N-applied. Urine was the main source of ammonia volatilization, and all estimates of volatilization losses were among the lowest reported in the literature.
Mircen Journal of Applied Microbiology and Biotechnology, 1987
... experienced. The distillates are titrated against a sulphuric acid solution (0.05-0.25 N), th... more ... experienced. The distillates are titrated against a sulphuric acid solution (0.05-0.25 N), this acid being standardized by titration against a solution of tris (hydroxymethyl) methylamine (THAM) as suggested by Keeney & Nelson (1982). ...
In a paper published recently in this Journal a new equation was presented for the calculation of... more In a paper published recently in this Journal a new equation was presented for the calculation of the proportion of plant nitrogen derived from plant-associated biological nitrogen fixation (BNF) using the ‘A-value’ technique. To apply this technique it is assumed that the specific availability (‘A-value’) of soil N is constant regardless of the quantity of added labelled N fertilizer. The
In the estimation of the contribution of biological nitrogen fixation (BNF) to plant nutrition ma... more In the estimation of the contribution of biological nitrogen fixation (BNF) to plant nutrition many authors have compared the estimates derived from the15N-isotope-dilution technique with those derived from the total N-difference technique. In this paper we show that agreement of these two estimates is mathematically inevitable when the recovery of labelled nitrogen (%FUE) by the “N2-fixing” (test) and control plants
Biological nitrogen fixation (BNF) associated with trees and shrubs plays a major role in the fun... more Biological nitrogen fixation (BNF) associated with trees and shrubs plays a major role in the functioning of many ecosystems, from natural woodlands to plantations and agroforestry systems, but it is surprisingly difficult to quantify the amounts of N2 fixed. Some of the problems involved in measuring N2 fixation by woody perennials include: (a) diversity in occurrence, and large plant-to-plant variation
A introducao de leguminosas em pastagens de gramineas, na forma de consorcio, tem sido apresentad... 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...
Resumo A cultura de capim elefante (Pennisetum purpureum Schum.) é altamente eficiente na fixação... more Resumo A cultura de capim elefante (Pennisetum purpureum Schum.) é altamente eficiente na fixação de CO2 (gás carbônico) atmosférico durante o processo de fotossíntese para a produção de biomassa vegetal. Por ser uma espécie de rápido crescimento, a biomassa de capim-...
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