• Authors:
    • Urquiaga, S.
    • Boddey, R. M.
    • Sant'Anna, S. A. C. de
    • Lessa, A. C. da R.
    • Paredes, D. da S.
    • Alves, B. J. R.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 98
  • Issue: 1
  • Year: 2014
  • Summary: In Brazilian sugarcane plantations, fertilization with vinasse, supplemented or not with mineral fertilizer, is a common practice. But little is known about the effects of this application on N losses, especially those forms of N which give rise to greenhouse gas emissions. The aim of this study was to quantify N2O and NH3 emissions from soil after vinasse application and urea fertilizer addition and to examine the possible impact adding vinasse before or after urea. Two experiments were conducted under greenhouse conditions and one in the field with treatments of vinasse and urea fertilizer, either alone, or in sequence. The highest proportions of N emitted as N2O were registered in the vinasse treatment, which amounted to 15 % of the N applied in the first greenhouse experiment, and 2.5 % in the field experiment. With respect to the losses by NH3 volatilization, urea was the only treatment where this process was significant. N2O emission from vinasse was 2.5 %, somewhat above the default emission factor of 1 % of the IPCC. N2O emissions from urea were also variable, but emission factors registered were still well below the default IPCC factor for organic residues. The order of addition of urea and vinasse had little effect on NH3 volatilization in the field, but there were evidences it was important for N2O.
  • Authors:
    • Lima, J. R. S.
    • Antonino, A. C. D.
    • Falcao, H.
    • Santos, O. O.
    • Lustosa, B. M.
    • Santos, M. G.
  • Source: Bragantia
  • Volume: 73
  • Issue: 2
  • Year: 2014
  • Summary: The present study evaluated the ecophysiological performance of species Zea mays (maize), Sorghum bicolor (sorghum) and Brachiaria decumbens (Brachiaria) under water deficit conditions in a greenhouse. The leaf water potential, gas exchange, chlorophyll a fluorescence and biochemical variables of photosynthetic metabolism were assessed at maximum stress and rehydration. At 90 days after emergence and under 21 days under suspension of irrigation the maize showed the highest reduction of leaf water potential (248%), stomatal conductance (87%) and photosynthesis (53%) when compared to well watered plants. Sorghum decreased by 212%, 42% and 26%, while the brachiaria showed lower values in 105%, 36% and 31%, respectively for the same parameters. However, two days of water supply were enough for all species recover the values showed by the respective controls. The species with the smallest decrease related to the variables evaluated was sorghum, which reduced 4 among 14 variables evaluated, while brachiaria and maize decreased 9 variables when under drought. The present study highlights that beyond economics, decision making by small farmers and technicians, about which species should be used under low availability of technology and high risk of water shortages should take into account also the ecophysiological performance.
  • Authors:
    • Carvalho, P. C. de F.
    • Anghinoni, I.
    • Assmann, J. M.
    • Ferreira, A. O.
    • Amado, T. J. C.
    • Silva, F. D. da
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 190
  • Year: 2014
  • Summary: Brazil has the world's second-largest cattle herd and second-largest no-till grain crop area. However, these activities are not frequently integrated because there is a widespread perception that cattle have a negative effect on cropping, especially when high crop yields are a goal. This misunderstanding of the synergy between pastures, livestock and crops is linked to overgrazing at the pasture rotation phase, which causes a decline in soil quality. Few studies have investigated the effect of pasture grazing intensities on soil carbon (C) balance and soil quality in subtropical environments. This work assessed the effects of different grazing intensities (0.10, 0.20, 0.30 and 0.40 m sward height) on soil C indices and animal productivity in a clay Haplorthox. The crop-livestock system model was a soybean/ryegrass plus black oat annual rotation managed for 10 years, using a randomized complete block design with three replications. Grazing intensity affected the quantity and composition of soil C input. Under heavy grazing with limited soil C input, there was a decrease in pasture and an increase in soybean participation in total C input. Soil organic C (0-0.20 m) under different grazing intensities had a linear relationship with C stratification ratio, C management index (CMI) and C pool index. Our results suggest that integrated crop-livestock systems could act as atmospheric C sources or sinks, depending on the grazing intensity. Pastures managed at 0.20 and 0.40 m height had the best balance between CMI and animal daily gain. The best balance between CMI and live weight gain per unit area occurred in sward height of 0.20 m.
  • Authors:
    • Calegari, A.
    • Balota, E. L.
    • Nakatani, A. S.
    • Coyne, M. S.
  • Source: Agriculture Ecosystems and Environment
  • Volume: 197
  • Year: 2014
  • Summary: Soil degradation in Brazil is a concern due to intensive agricultural production. Combining conservation practice, such as no-tillage, with winter cover crops may increase microbial activity and enhance soil quality more than either practice alone. This research evaluated the benefits of long-term (23 years) winter cover crops and reduced tillage on soil microbial quality indicators in an Oxisol from Parana State, Southern Brazil. The winter cover treatments were: fallow, black oat, wheat, radish, blue lupin, and hairy vetch in conventional (plow) or no-tillage management; the summer crop was a soybean/maize rotation. Soil quality parameters included organic C, microbial biomass C and N, total and labile polysaccharide, easily extractable and total glomalin-related soil protein, and enzyme activity. Winter crops increased soil microbial quality parameters compared to fallow in both tillage systems, with greater relative increase in conventional than no-tillage. No-tillage had higher microbial biomass, polysaccharide, glomalin-related soil protein, and soil enzyme activity than conventional tillage. Including legumes in the crop rotation was important for N balance in the soil-plant system, increasing soil organic C content, and enhancing soil quality parameters to a greater extent than grasses or radish. The microbial parameters proved to be more sensitive indicators of soil change than soil organic C. Cultivating winter cover crop with either tillage is a beneficial practice enhancing soil microbial quality and also soil organic C stocks.
  • Authors:
    • Nogueira, P. S.
    • Albernaz-Silveira, R.
    • Da Silva, C. J.
  • Source: CLIMATIC CHANGE
  • Volume: 127
  • Issue: 1
  • Year: 2014
  • Summary: The latest scientific findings indicate that the increased concentration of greenhouse gases emitted by anthropogenic sources is significantly altering the balance of the global climate system. Considering forecasts of changes in the hydrological cycle and temperature related to global warming, the dynamics governing the functioning of the Pantanal Wetland, responsible for its rich biodiversity, find themselves threatened. Thus, this study was designed in the space-time of the Pantanal people called pantaneiros, and aims to discuss the Traditional Ecological Knowledge (TEK) of the Traditional Community Cuiaba Mirim regarding climate change. The information presented was obtained from 22 pantaneiros, between March 2008 and March 2010. The population sample was selected by the Snow Ball method. For data collection, semi structured interviews and oral histories were used. The results were compared with observations, simulations and projections of the IPCC AR4 for the region. The main findings of this research indicate that TEK presents itself as a crucial and complementary source of information for the development of local/regional adaptation strategies to climate change, bringing a distinct and relevant point of view from vulnerable stakeholders to the decision makers.
  • Authors:
    • D'Agostini, L. R.
    • Bonatti, M.
    • Fantini, A. C.
    • Lana, M. A.
    • Schlindwein, S. L.
    • de Vasconcelos, A. C. F.
    • Martins, S. R.
  • Source: CLIMATIC CHANGE
  • Volume: 127
  • Issue: 1
  • Year: 2014
  • Summary: The La Plata Basin (LPB) is one of the most important regions for agriculture and livestock production in South America, playing a central role in the world food production and food security. Within its borders is also located the whole Brazilian Pantanal region. Identifying the most important land use sectors in LPB as well as the changes observed in the past years is fundamental to recognize which areas of the basin might be more vulnerable to climate change in order to design adaptation strategies. A general characterization of land use and livestock production of Brazilian LPB was done by using the System of Automatic Retrieving (SIDRA) of Brazilian Institute of Geography and Statistics (IBGE) platform as the major source of data. It was observed expressive increases in land areas used for temporary crops, such as soybean, sugarcane, and maize, as well as increases in poultry and swine production. These important changes in agricultural land use and livestock production are currently associated to non-climatic drivers, but this dynamic might be strongly affected by the consequences of climate change and variability, with negative socio-economic impacts for the whole region.
  • Authors:
    • Hastings, A.
    • Galdos, M.
    • Smith, P.
    • Del Grosso, S.
    • Parton, W.
  • Source: CURRENT OPINION IN ENVIRONMENTAL SUSTAINABILITY
  • Volume: 9-10
  • Year: 2014
  • Summary: Biofuels currently supply a small portion of the world's energy needs but this is increasing due to mandates intended to reduce use of fossil fuels and the associated environmental impacts. However, the potentials of plant based feedstocks to substitute for fossil fuels and mitigate environmental impacts are uncertain. Much of the uncertainty is related to the quantification of nitrous oxide (N2O) emissions from feedstock production and the extent to which use of grain and biomass for biofuel feedstocks leads to land use conversion for compensatory cropping (indirect land use change). Current consensus is that sugar cane, perennial cellulosic crops, and waste biomass provide clear benefits while corn ethanol and oil seed crops may provide benefits if indirect land use change is assumed to be negligible and if recommended crop management practices, such as use of enhanced efficiency fertilizers and minimal tillage, are employed. Future research should better quantify N2O emissions from different feedstocks grown in different regions, the ability of best management practices to mitigate these emissions, and the potential for marginal lands and increased crop yields to supply biomass.
  • Authors:
    • Girard, P.
    • Irigaray, C. T.
    • Ioris, A. A. R.
  • Source: CLIMATIC CHANGE
  • Volume: 127
  • Issue: 1
  • Year: 2014
  • Summary: Climatic change is expected to have serious impacts on the Pantanal, a large tropical wetland located in the Upper Paraguay River Basin, in the centre of South America, where a range of institutional responses are being developed to mitigate and adapt to climate change. In order to examine the institutional achievements and challenges for managing the region, a specific typology is initially introduced, which comprises a schematic gradient of institutional responses. An empirical analysis was conducted in Brazil, Bolivia and Paraguay, the three countries that share the Pantanal, which identified the hybrid basis of the policy framework under construction, in the sense that it actually combines elements of various institutional responses included in the proposed typology. Important factors that seem to undermine the efficacy of institutional responses in addressing climate change in the region are the strong influence of the agribusiness sector and the still relatively low importance of the Pantanal for national environmental policy-making. This essay makes a claim that the principles of climate justice should guiding policies and interventions as it they constitute the most appropriate strategy to address the inequality and unfairness related to climate change.
  • Authors:
    • Berger, T.
    • Latynskiy, E.
    • Troost, C.
  • Source: International Environmental Modelling and Software Society (iEMSs)7th Intl. Congress on Environmental Modelling and Software, San Diego, CA, USA,Daniel P. Ames, Nigel W.T. Quinn and Andrea E. Rizzoli(Eds.)
  • Volume: 4
  • Year: 2014
  • Summary: Agriculture and agriculture-inflicted land use change is a major source of greenhouse gas (GHG) emissions. Reducing excessive deforestation and intensification of agricultural land use and consequently reducing associated GHG emissions is an important pathway of transition to a global low-carbon economy. Adoption of low-carbon agricultural systems and practices requires setting appropriate economic incentives for land users through smart policy instruments. For effective implementation of such instruments integrated ex-ante policy assessments are crucial. In this article we discuss and illustrate the benefits and potentials of applying multi-agent system models for the assessment of low-carbon policies and technologies. As an empirical example we discuss the use of the software package MPMAS that we are currently deploying for the assessment of impacts of low-carbon technologies and policies in the Southern part of Brazilian Amazon. Our agent-based application implements one-to-one correspondence between real-world farms and computational agents and is able to realize spatially explicit simulations of farm behavior. MPMAS is externally coupled with the dynamic, process-based crop growth model MONICA hereby interlinking economic behavior of farms with processes of carbon, nitrogen and water turnover. The values of GHG emissions are simulated by the biochemistry model DNDC, which was calibrated in situ based on empirical measurements. Our application has a graphical GIS-interface that can inform policy evaluators about simulated results.
  • Authors:
    • Bursztyn, M.
    • Eiro, F.
    • Parente, I. I.
    • Debortoli, N.
    • Rocha, J. D.
    • Lindoso, D. P.
    • Rodrigues-Filho, S.
  • Source: CLIMATIC CHANGE
  • Volume: 127
  • Issue: 1
  • Year: 2014
  • Summary: Smallholder farming is among the most vulnerable sectors due to its great social and economic sensitivity. Despite future climate change, current climate variability is already an issue of concern that justifies adaptation efforts. In Brazil, the Semi-Arid Region is a climate hotspot, well known for both historic socioeconomic setbacks, and agriculture failures caused by dry spells and severe droughts. In 2010, the Brazilian government enacted the National Policy on Climate Change, which states as one of its key goals the identification of vulnerabilities and the adoption of adequate measures of adaptation to climate change. The improvement of vulnerability assessment tools is a response to the growing demand of decision makers for regular information and indicators with high spatial and temporal resolution. This article aims at undertaking a comparative assessment of smallholder farming's vulnerability to droughts. An integrated assessment system has been developed and applied to seven municipalities located in the Brazilian Semi-Arid Region (within the State of Ceara). Results show regional vulnerability contrasts driven by institutional and socioeconomic factors, beyond climatic stressors.