In Brazil’s central savanna region, government policy is to encourage the conversion of conventional plough tillage (PT) agriculture to no-till (NT) and raise the productivity of under-utilized pastures, including their conversion to integrated crop-livestock (ICL) systems, with the objective of increasing soil organic carbon (SOC) at the expense of atmospheric carbon dioxide. An experiment was established in 1991 by liming and fertilizing at two levels an area of native vegetation (NV). The treatments, replicated in randomized plots, included pastures, continuous cropping and ICL systems under PT or NT. The aim of this study was to quantify the SOC accumulation to 100 cm depth under these treatments over time. The high C:N ratios suggested that there was a high proportion of charcoal present in the soil. Increasing fertilizer inputs had no overall significant effect on SOC stocks. Stocks of SOC changed little under pastures. Analyses of ¹³C abundance showed that higher fertilizer inputs increased the decomposition rate of C derived from NV under pure grass pastures. Continuous cropping under NT preserved SOC and under PT there were significant losses. The highest SOC stocks were found under ILP treatments, but not all ILP treatments accumulated SOC even under NT. These results indicate that government initiatives to substitute PT with NT and to intensify beef cattle production will have only modest short-term gains in SOC accumulation.

O objetivo deste trabalho foi avaliar o potencial de mitigação de óxido nitroso (N2O) em sistema de integração lavoura-pecuária-floresta (ILPF), em comparação ao monocultivo, e identificar os principais fatores que regulam as emissões deste gás. O experimento foi realizado em Sinop, MT, entre as safras 2012/2013 e 2013/2014, e avaliou os seguintes tratamentos: floresta, lavoura e pastagem, além do ILPF. Durante a realização do experimento, não houve presença de bovinos nas áreas com pastagem. Amostras de óxido nitroso foram coletadas semanalmente, com uso de câmaras estáticas, modelo topo-base. As concentrações do gás foram determinadas por meio de cromatografia gasosa. A precipitação pluvial e a disponibilidade de N foram os principais fatores reguladores das emissões de N2O. O sistema de ILPF apresenta potencial promissor para mitigar as emissões de N2O, com emissão acumulada de 0,367 kg ha-1 de N, em comparação a de 1,401 kg ha-1 emitidas pela lavoura; de 0,298 kg ha-1, pela pastagem; e de 0,165 kg ha-1, pela floresta.

Despite environmental damage of cow meet production residues, specific methods to evaluate its spatial impact on soil contamination are sparse and time consuming. This study aimed to evaluate the potential of spectroscopy (400–2500 nm) to detected soil contaminated with organic compounds. It was conducted two experiments: (1) Three soils were incubated with pure and diluted blood from slaughterhouse in a greenhouse, and spectral data were obtained in laboratory with a FieldSpec sensor. (2) Field experiment was conducted to prove its approach. Soil spectral responses were evaluated by qualitative and quantitative methods, and chemical analyses were carried out. The addition of residues increased levels mostly of Na (92.9 %), Ca (80.9 %) and K (82.7 %). N and C increased 52.7 %. This high significant addition resulted on a decrease in soil reflectance intensity in all spectral ranges. These changed slightly at 650, 1450, 1550, 1900 and 2100 nm indicating alteration due to cation on the CEC of minerals. Principal components and soil line analyses corroborated the discrimination of samples quantification of Na, K, Ca and Mg, where R² vary from 0.68 until 0.85. In field areas with and without the waste also showed different spectra. Spectra were also able to analyze samples located downhill from the area with waste, indicating the presence of the waste close to streams, which came by leaching. The results indicate that it is possible to identify areas with organic residue by a quick method as compared with traditional soil analysis, helping man power inspection.

A total of 70 Nellore bulls (18 ± 3 months of age) were used to determine the effects of crude glycerine (CG) replacing starch- v. fibre-based energy ingredients in low (LC; 0·40 concentrate) or high concentrate (HC; 0·60 concentrate) – on a dry matter (DM) basis – on DM intake (DMI), methane emissions and growth. Ten bulls were slaughtered (reference group) to obtain the carcass gain (CrG). The 60 remaining bulls (374 ± 24·5 kg) were allocated to a 2 × 3 factorial arrangement (two concentrate levels, LC or HC; and three feeding regimes, FR). The FR were: CO – without CG and maize as an ingredient of concentrate; CGM – inclusion of CG (0·10 of DM) replacing maize in the concentrate; and CGSH – inclusion of CG (0·10 of DM) replacing soybean hulls (SH) in the concentrate. Bulls fed LC or HC had similar DMI (kg/d) and growth. The DMI and average daily gain (ADG) were similar among FR. Concentrate level and FR tended to interact for methane emissions (g) per kg DMI. Bulls fed CGM had a greater G : F (g CrG/kg DMI) than those fed CO or CGSH diets. Increasing dietary concentrate (0·40–0·60) did not affect intake, methane emissions, or growth. Inclusion of CG in diets to replace SH in LC diets tended to decrease methane emissions from animals. When CG replaces SH in the diets, CrG and G:F (g CrG/kg DMI) are decreased compared with bulls fed CGM.

Fatty acid profile of crossbred beef cattle fed either a diet with corn gluten and protected fat (A) or a control diet (B) was evaluated. Animal’s gender and diet had greater influence on fatty acid profile than genotype. Diet A increased polyunsaturated fatty acids/saturated fatty acids ratio and decreased t11/t10-18:1 ratio and n-6 content.

Este artigo mostra os resultados de pesquisa para o semiárido pernambucano utilizando séries temporais diárias de temperatura e de precipitação com mais de 40 anos, com cenários futuros de mudanças do clima para o período de 2010 a 2050. Para determinar as tendências de mudanças do clima, presente e futuro, foram utilizadas tendências de mudanças climáticas, resultados de balanço hídrico e saídas do modelo atmosférico regional aninhado ETA, em cenário global do modelo climático aninhado em dois modelos climáticos globais, HadCM3 e BESM. Os resultados indicaram tendência de aumento das temperaturas máximas, redução das temperaturas mínimas, redução da pluviosidade, média anual, indicando tendência à aridização na região.

Durante as últimas décadas, com as fortes evidências do aquecimento global, ganham importância os estudos sobre o comportamento e as mudanças dos padrões em séries climáticas. Para a coerência nas análises de dados, o processo probabilístico gerador dos valores da variável aleatória ao longo do tempo deve permanecer o mesmo. No caso de dados de estações meteorológicas, este pressuposto de homogeneidade no processo estocástico pode ser violado a partir de perturbações como mudanças de posição da estação, mudança de instrumentos ou mudança climática.
Neste trabalho, o pacote Climatol-R foi aplicado a 122 séries mensais de temperatura mínima, cobrindo o interior do estado de São Paulo para os anos 1940 até 2012. Todas as estações estudadas apresentaram não homogeneidades. Uma das consequências deste trabalho de homogeneização foi a melhora da homogeneidade dos dados de temperatura mínima para a estação meteorológica IAC.00015 onde se obteve redução do desvio padrão de 0,86ºC para 0,81ºC. O pacote Climatol-R tende a melhorar espacialmente e temporalmente a série original, apresentando melhores resultados para a análise de variabilidade climatológica.

Research networks provide a framework for review, synthesis and systematic testing of theories by multiple scientists across international borders critical for addressing global-scale issues. In 2012, a GHG research network referred to as MAGGnet (Managing Agricultural Greenhouse Gases Network) was established within the Croplands Research Group of the Global Research Alliance on Agricultural Greenhouse Gases(GRA). With involvement from 46 alliance member countries, MAGGnet seeks to provide a platform for the inventory and analysis of agricultural GHG mitigation research throughout the world. To date, metadata from 315 experimental studies in 20 countries have been compiled using a standardized spreadsheet. Most studies were completed (74%) and conducted within a 1–3-year duration (68%). Soil carbon and nitrous oxide emissions were measured in over 80% of the studies. Among plant variables, grain yield was assessed across studies most frequently (56%), followed by stover (35%) and root (9%) biomass. MAGGnet has contributed to modeling efforts and has spurred other research groups in the GRA to collect experimental site metadata using an adapted spreadsheet. With continued growth and investment, MAGGnet will leverage limited-resource investments by any one country to produce an inclusive, globally shared meta-database focused on the science of GHG mitigation.

The recent article in this journal of Cerri et al. (2016) gives estimates of greenhouse gas (GHG) emissions for cattle production on extensively managed farms in the State of Mato Grosso, Brazil. The results are expressed as GHG emission per kg of animal in the herd, and not per kg of product. These estimates should not be referred to as “carbon footprints” as they do not reflect the estimate of the GHG emissions utilized in the production of 1 kg of animal or carcass, but the total emission per kg of the total mass of animals in the herd, whether calves, heifers, steers or mature bulls and cows. This leads to a large underestimation of the true GHG emissions for the production of Brazilian beef.

Few grass genotypes with high yield potential are used as fodder in Brazil, making it necessary to develop new cultivars. In this study, we compared tiller density, forage mass, and agronomic traits across 12 Elephant grass (Pennisetum purpureum Schum.) genotypes under free-growth and conventional cutting systems at the Agência Paulista de Técnologia dos Agronegócios (APTA), Andradina, São Paulo, Brazil. The experimental design of the two trials was three replicates of a randomized complete block, each experimental unit consisting of 37.5-m2 plots with five rows spaced 1.5 m apart. We estimated tiller density 30, 60, and 150 days after planting (DAP), and 90 days after cut (DAC), and harvested the grass 150 DAP and 90 DAC for determination of forage mass and agronomic traits. In the free-growth system, forage mass was highest in genotypes CNPGL 00-155-2, CNPGL 92-41-1, CNPGL 92-51-1, and CNPGL 96-21-1 and in cultivar Guaçu. After cutting and regrowth, forage mass was highest in genotypes CNPGL 93-41-1, CNPGL 92-41-1, and CNPGL 91-11-2 and in cultivars Mineiro IPEACO, Guaçu, and Pioneiro. Stem mass was higher than leaf mass in the two trials, with leaf/stem ratio in most genotypes below 1.0. Aerial tiller density was highest for genotypes Pioneiro and CNPGL 00-155-2, and stem diameter was smallest in cv. Pioneiro in the free-growth and in the cutting and regrowth systems (9.7 and 7.62 mm, respectively). After regrowth, plant height ranged from 0.56 m in cv. Guaçu to 2.0 m in cv. Mineiro IPEACO and the mean number of internodes.stem-1 ranged from 2.1 in cv. Guaçu to 7.4 in cv. Pioneiro. Forage mass correlated positively with basal tiller density (r =0.4096) and negatively with stem diameter (r =-0.4879) in the free-growth trial, but relationships were not significant after regrowth.

The objective of this study was to evaluate the effect of seasons under a tropical climate on forage quality, aswell the effect of an Urochloa brizantha cv. Marandu grazing system on enteric methane (CH4) emissions fromNellore cattle in the Southeast region of Brazil. Sixteen Nellore steers (18 months old and initial weight 318.0 ± 116.59 kg of LW; final weight 469 ± 98.50 kg of LW) were used for a trial period of 10 months, with four collection periods in winter (August), spring (December), summer (February) and autumn (May). Each collection period consisted of 28 days, corresponding to the representative month of each season where the last six days were designed for methane data collection. Animals were randomly distributed within 16 experimental plots, distributed in four random blocks over four trial periods. CH4 emissions were determined using the sulphur hexafluoride (SF6) tracer gas technique measured by gas chromatography and fluxes of CH4 calculated. The forage quality was characterized by higher CP and IVDMD and lower lignin contents in spring, differing specially from winter forage. Average CH4 emissions were between 102.49 and 220.91 g d-1 (37.4 to 80.6 kg ani-1 yr-1); 16.89 and 30.20 g kg-1 DMI; 1.35 and 2.90 Mcal ani-1 d-1; 0.18 and 0.57 g kg-1 ADG-1 and 5.05 and 8.76% of GE. Emissions in terms of CO2 equivalents were between 4.68 and 14.22 g CO2-eq-1 g-1 ADG. Variations in CH4 emissions were related to seasonal effect on the forage quality and variations in dry matter intake.

We aimed to quantify nitrous oxide (N₂O) and methane (CH₄) emissions as a function of the addition of different quantities of bovine faeces and urine on soil under pasture. Two experiments were performed in randomised complete blocks with five replicates. In the first experiment, the emissions of CH₄ and N₂O were evaluated for 14 days after the addition of four amounts of faeces (0.0, 1.2, 1.8 and 2.4 kg of fresh faeces per plot), and in a second experiment, N₂O emissions were evaluated for 43 days after addition of four volumes of urine (0.0, 1.0, 1.5 and 2.0 L). Urine and faeces came from crossbred (Fresian × Gir) dairy cows fed on pasture and concentrates. N₂O emissions from faeces did not alter the emission factor (EF) according to the faeces weight (P = 0.73). N₂O-N EF from faeces-N averaged 0.18% (±0.05) of total applied N. The volume of urine applied influenced N₂O losses. The EF decreased linearly (P = 0.015) with increasing volumes of urine, being 4.9% (±0.75), 3.36% (±0.7) and 2.43% (±0.46) of N applied emitted as N₂O for the 1.0, 1.5 and 2.0 L volumes of urine respectively. The EF from urine was significantly (P < 0.0001) higher than the EF from faeces. There was no change to the CH₄ emissions per kilogram of excreta when the amount of faeces added was varied (P = 0.87). However, the CH₄ emitted increased linearly with the amount of faeces (P = 0.02). The CH₄ EF was estimated to be 0.95 (±0.38) kg/head.year.