• Authors:
    • Raucci,G. S.
    • Moreira,C. S.
    • Alves,P. A.
    • Mello,F. F. C.
    • Frazão,L. D. A.
    • Cerri,C. E. P.
    • Cerri,C. C.
  • Source: Journal of Cleaner Production
  • Volume: 96
  • Year: 2015
  • Summary: Abstract In recent years, the debate about environmental impacts and the sustainability of agricultural products has increased. Environmental impact indicators are increasingly being demanded for policy and decision-making processes. Consumers are more and more concerned about the quality of food products and now looking for those with a low environmental impact, with a particular attention to greenhouse gas (GHG) emissions. There are few studies regarding the GHG emissions associated with the Brazilian soybean production. The aim of this study was to evaluate the main sources of GHG in soybean production in the State of Mato Grosso, Brazil. Our analysis considered the Life Cycle Assessment (LCA) from cradle to farm gate. We evaluated 55 farms in the crop years of 2007/08, 2008/09 and 2009/10, accounting for 180,000 ha of soybean cultivation area and totaling 114 individual situations. The results indicated that the largest source of GHG in the soybean production is the decomposition of crop residues (36%), followed by fuel use (19%), fertilizer application (16%), liming (13%), pesticides (7%), seeds (8%) and electricity consumed at the farms (2eq kg-1 of soybean produced. We also categorized the results based on land use intensity and production areas. This study contributed to identify the main sources of GHG in the soybean production and indicate mitigation priorities associated to the soybean cultivation in Brazil. Further studies, including field experiments, should contribute to a better understanding of the profile of emissions from crop residues in Brazil. © 2014 Elsevier Ltd. All rights reserved.
  • Authors:
    • Yang, J.
    • Ren, W.
    • Lu, C.
    • Tao, B.
    • Tian, H.
    • Banger, K.
  • Source: Agronomy Journal
  • Volume: 79
  • Issue: 3
  • Year: 2015
  • Summary: To the best of our knowledge, no attempts have been made to understand how environmental changes that occurred in the 20th century have altered soil organic carbon (SOC) dynamics in India. In this study, we applied a process-based Dynamic Land Ecosystem Model (DLEM), to estimate the magnitude as well as to quantify the effects of climate change and variability, land cover and land-use change (LCLUC), carbon dioxide (CO2) concentration, atmospheric nitrogen deposition (NDEP), and tropospheric ozone (O3) pollution on SOC stocks in India during 1901-2010. The DLEM simulations have shown that SOC stocks ranged from 20.5 to 23.4 Pg C (1 Pg = 1015 g), majority of which is stored in the forested areas in the north-east, north, and few scattered regions in the southern India. During the study period, soils have sequestered SOC by 2.9 Pg C. Elevated CO2 concentration has increased total SOC stocks over the country by 1.28 Pg C, which was partially offset by climate change (0.78 Pg C) and tropospheric O3 pollution (0.20 Pg C) during 1901-2010. Interestingly, LCLUC increased SOC stocks by 1.7 Pg C thereby suggesting that SOC loss from deforestation was offset by the conversion of low productive fallow lands and other lands to croplands that received irrigation along with N fertilizers. Atmospheric nitrogen deposition (NDEP) has increased biomass production and SOC by 0.5 PgC over the country. This study has demonstrated that the benefits from elevated CO2 concentration, cropland management practices, and NDEP in sequestering SOC stocks were offset by climate change and tropospheric O3 pollution which should be curbed in India. © Soil Science Society of America, 5585 Guilford Rd., Madison Wl 53711 USA.
  • Authors:
    • Lehmann, J.
    • Lamers, J.
    • Bationo, A.
  • Source: Article
  • Volume: 102
  • Issue: 1
  • Year: 2015
  • Authors:
    • Narh, S.
    • Akponikpe, P. B. I.
    • MacCarthy, D. S.
    • Tegbe, R.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 102
  • Issue: 1
  • Year: 2015
  • Summary: This study set out to (1) calibrate and evaluate the performance of APSIM in simulating maize response to N, P and residue management and (2) identify strategies to reduce instability in crop production, and increase the efficiency of mineral fertilizer use. The response of maize to inorganic nitrogen (N) and phosphorus (P) additions were determined in the coastal savannah agro-ecology in the main rainy and secondary rainy seasons, of 2008 and 2009. Field experiments were set-up in a randomized complete block design with different levels of N (0-120 kg N ha(-1)) and P (0-30 kg P2O5 ha(-1)) mineral fertilizer. The APSIM model adequately simulated agroecosystem dynamics, resulting in the following RMSE values: anthesis (1.2 days), maturity (2.0 days), maximum LAI (0.18 m(2)m(-2)) total-biomass (543 kg ha(-1)), grain yield (318 kg ha(-1)), N uptake (12.6 kg ha(-1)), P uptake (2.2 kg ha(-1)) and in-season soil water content (0.01 mm). A long-term simulation study (30 years) showed that probabilities of obtaining higher yields were higher in the main growing season than in the secondary growing season. The efficiency of mineral N fertilizer use was also higher in the main growing season. The use of 40 kg N ha(-1) mineral N fertilizer in both seasons was more efficient than using 80 kg N ha(-1). The variability in the efficiency of mineral fertilizer use was higher in the secondary growing (44-96 %) than in the main growing season (27-48 %). Retaining crop residues yielded higher stability in grain production and increased the minimum grain yield production significantly. Applying 40 kg N ha(-1) and 30 kg P2O5 ha(-1) mineral fertilizer with crop residue retention will reduce the uncertainty in maize production, particularly in the secondary growing seasons which are characterized by prolonged drought spells. This study suggests that resource-poor farmers will be better off prioritizing the main growing season for rainfed maize production and applying a moderate amount (40 kg N ha(-1)) of N fertilizer rather than the 90 kg N ha(-1) currently recommended for the coastal savannah of Ghana in the secondary growing season because of the higher instability in yields associated with N fertilizer use in this season.
  • Authors:
    • Naab,J. B.
    • Mahama,G. Y.
    • Koo,J.
    • Jones,J. W.
    • Boote,K. J.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 102
  • Issue: 1
  • Year: 2015
  • Summary: Sustainable management practices are needed to enhance soil organic carbon (SOC) in degraded soils in semi-arid West Africa. We studied the effects of three amounts of nitrogen (N) (0, 60 and 120 kg N ha(-1)) and three amounts of phosphorus (P) fertilizer (0, 26 and 39 kg P ha(-1)) application over four seasons on maize residue production, residue C, N, and P concentrations, and their impacts on SOC, total soil nitrogen (TSN), and total soil phosphorus (TSP) in the 0-20 cm soil layer. Combined application of N and P fertilizers substantially increased maize grain yield on average by 294 % and biomass produced and returned to the soil by about 60-70 % compared with no fertilization. Annual C, N, and P inputs from crop residue were significantly higher with combined application of N and P fertilizer. The increased amount of crop residue and consequent increased residue C, N and P returned to the soil significantly increased SOC, TSN and TSP in the 0-20 cm soil layer after four seasons. There was a significant correlation between the amount of crop residues returned to the soil over four seasons and SOC (r = 0.82; P = 0.007), TSN (r = 0.75; P = 0.020) and TSP (r = 0.69; P = 0.039). We concluded from these experiments that returning crop residues, application of inorganic fertilizer improves SOC, TSN and TSP concentrations and enhances crop productivity. The farmers who traditionally remove crop residues for fodder and fuel will require demonstration of the relative benefits of residues return to soil for sustainable crop productivity.
  • Authors:
    • Normand,F.
    • Lauri,P. E.
    • Legave,J. M.
  • Source: Acta Horticulturae
  • Volume: 1075
  • Year: 2015
  • Summary: Climate change is becoming an observed reality, very likely due to the increase of anthropogenic greenhouse gas concentration. Since a few decades, several research teams around the world carry out a huge work to model the future climatic change during the 21st century, based on several scenarios of greenhouse gas emission. We have to expect rise in average temperatures, in atmospheric CO 2 concentration, in soil salinity in some areas, and lower and more irregular rainfall. The climate variability and the frequency of extreme events (scorching heat, heavy rainfall, drought, hurricane) are also expected to rise. Climate change is therefore a great concern for agriculture. Mango is one of the most widely cultivated and popular fruits in these regions for its economic and nutritional values. It is the fifth most cultivated fruit in the world. It is consequently justified to wonder about the impact of climate change on the mango tree and about the consequences on mango production and cultivation. The lack of crop model for mango prevents the prediction of the effects of climate change on mango tree development and production. They are then assessed on the basis of our current knowledge on the influence of climatic variables on mango tree development and production. We describe the influence of climatic variables on processes of agronomical importance for the mango tree: photosynthesis, vegetative and reproductive development, fruit quality. We then review the climate changes predicted for two areas of mango production and draw the possible consequences for mango cultivation. Finally, we propose some research ways to adapt mango cultivation to climate change in the coming decades, such as cultivar and rootstock selection, and improvement of cultural practices. The interest of developing a mango crop model is discussed.
  • Authors:
    • Rati Mukteshawar
    • Shehrawat,P. S.
  • Source: Annals of Biology
  • Volume: 31
  • Issue: 1
  • Year: 2015
  • Summary: As we know, that agriculture has been an important profession for Indian as well as for the people of the world. The world's population is growing at an alarming rate with corresponding increase in demand for food goods and natural resources, so it directly burdens the agriculture to meet the consumption needs, farmers really more depend upon inorganic farm inputs. As a consequence of increase in inorganic farm inputs consumption, vast quantities of gases and effluents are discharged that may change the climate composition of the atmosphere and its capacity to regulate its temperature that's why world agriculture is facing numerous newly emerged challenges, the most prominent challenges are such as climate change and effect of greenhouse gases on agricultural practice. Mostly scientists now agree that rising atmospheric concentrations of GHG threaten to have severe impacts on food production, natural ecosystems and human health. Now-a-days, the agricultural scientists and extension clienteles have preference for demand driven and participatory approaches. The need to provide up-to-date information by the extension workers regarding to causes of GHG emissions and how it affects the agricultural production. Due and focuses efforts have to be made regarding the transfer of new agricultural technologies efficiently and effectively. A total number of eight villages were selected randomly. From each village, 15 farmers were selected randomly. Hence, a total number of 120 farmers were interviewed. The study revealed that farmers had awareness about GHG (65.00%), followed by knowledge about GHG (39.16%), major source of GHG emissions (73.33%), livestock also emit GHG (35.83%) and losses due to GHG in agriculture (68.33%). Whereas farmers were not aware regarding attending any meeting/workshop/training regarding sequestration of GHG (67.50%), farmers changed their cropping patterns (50.00%) and observation regarding deterioration in quality of crop produce (42.50%). The study further revealed that farmers were found agreed about change in current farm management practices (85.00%), change in season length (89.16%), altering the farming practices of field operations (97.50%), change in seasonal temperature (91.66%), changes in time of precipitation (82.00%), increase in flood and drought (72.50%) and 'fluctuation in ground water table' (88.33%). Whereas farmers were found undecided about emission of GHG which is not a problem for agricultural practices (82.50%), no effect of GHG emission on crop production (64.16%) and no effect of GHG emission on livestock production (70.00%). Farmers' were found disagreed regarding no effect of GHG emission on bio-diversity (33.33%), change in timing of precipitation (17.50%) and increase the incidence of falling hail (14.16%).
  • Authors:
    • Reichert,J. M.
    • Rodrigues,M. F.
    • Bervald,C. M. P.
    • Brunetto,G.
    • Kato,O. R.
    • Schumacher,M. V.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 204
  • Year: 2015
  • Summary: No-tillage planting in mechanically-chopped secondary-forest seeks to replace slash-and-burning agriculture. We evaluated the effect of horizontal (HC) and vertical (VC) chopping-and-mulching mechanisms on vegetation fragmentation and decomposition rate and nutrient release from chopped residue, and on cassava production in eastern Amazon. Chopped-and-mulched residue was classified into four residue-size (Fs 1=1-7, Fs 2=7-25, Fs 3=25-35, and Fs 4=>35 mm) and six residue-type (with husk/bark - WB, partially chopped - PC, compact - C, partially shredded into fibers - PS, completely shredded into fibers - CS, and formless residue - F) classes. In litter-bags, residual dry matter (DM) was determined at five different days after chopping-and-mulching and residue distribution on soil surface (DAD), whereas release of N, P, K, Ca, and Mg was evaluated at four days. Residues-size and -type classes showed similar decomposition behavior, with a reduction of approximately 60% of initial DM at 90 DAD. Nevertheless, reduction in DM was slow, where 52 days are necessary for half of labile residue to be decomposed, with part of labile and recalcitrant residue remaining on soil surface. DM and nutrients in residue reduced over time. DM was 25% for residues-size classes for HC, 20% for VC, and 26% for residue-type classes, on average, at 300 DAD. Nutrients remaining in residues at 300 DAD were 26% and 27% of N, 26% and 22% of P, 29% and 22% of K, 16% and 15% of Ca, and 17% and 23% of Mg, respectively for HC and VC. Release of nutrients was, generally, greater for smaller residue-size classes, similar between chopping-and-mulching mechanisms, and did not affect cassava yield.
  • Authors:
    • Santana,T. A. de
    • Oliveira,P. S.
    • Silva,L. D.
    • Laviola,B. G.
    • Almeida,A. A. F. de
    • Gomes,F. P.
  • Source: Biomass and Bioenergy
  • Volume: 75
  • Year: 2015
  • Summary: In order to quantify the water use efficiency and water consumption during the early growth of Jatropha curcas L., three genotypes were grown in pots under greenhouse conditions, and subjected to two watering regimes: irrigated (substrate matric potential (Psi m) of -9.8 to -7.4 kPa) and water deficit (Psi m=-98.6 to -33.5 kPa). Independent of watering regime, the genotypes did not differ on the variables analyzed. Despite the reduction of substrate water content in water deficit treatment, no significant decrease (p<0.05) of leaf water potential (Psi w) was observed, which suggests some water redistribution from the succulent stems of J. curcas. The values of net photosynthetic rate ( A), stomatal conductance ( gs), and transpiration ( E) were reduced to 80, 90 and 85%, respectively, as compared to control plants. Moreover, drought led to 78% reduction in hydraulic conductance ( KL ). At the end of the experiment, the average water consumption in water deficit plants was 27% lower than in control plants. Drought-induced decrease in biomass production led to reduction of water use efficiency of biomass (WUE Biomass). However, due to the more significant effect on gs and E than A at 66 DAIT, intrinsic ( A/gs) and instantaneous efficiency ( A/E), water use increased 50% and 27%, respectively. The results showed that there was no intergenotypic variation for the traits evaluated, and that the reduction of water availability in the substrate proved to be an effective technique in the increase of photosynthetic efficiency of water use in plants of J. curcas, reducing water consumption in this species.
  • Authors:
    • Singh,R. J.
    • Ahlawat,I. P. S.
  • Source: Environmental Monitoring and Assessment
  • Volume: 187
  • Issue: 5
  • Year: 2015
  • Summary: Two of the most pressing sustainability issues are the depletion of fossil energy resources and the emission of atmospheric green house gases like carbon dioxide to the atmosphere. The aim of this study was to assess energy budgeting and carbon footprint in transgenic cotton–wheat cropping system through peanut intercropping with using 25–50 % substitution of recommended dose of nitrogen (RDN) of cotton through farmyard manure (FYM) along with 100 % RDN through urea and control (0 N). To quantify the residual effects of previous crops and their fertility levels, a succeeding crop of wheat was grown with varying rates of nitrogen, viz. 0, 50, 100, and 150 kg ha-1. Cotton + peanut–wheat cropping system recorded 21 % higher system productivity which ultimately helped to maintain higher net energy return (22 %), energy use efficiency (12 %), human energy profitability (3 %), energy productivity (7 %), carbon outputs (20 %), carbon efficiency (17 %), and 11 % lower carbon footprint over sole cotton–wheat cropping system. Peanut addition in cotton–wheat system increased the share of renewable energy inputs from 18 to 21 %. With substitution of 25 % RDN of cotton through FYM, share of renewable energy resources increased in the range of 21 % which resulted into higher system productivity (4 %), net energy return (5 %), energy ratio (6 %), human energy profitability (74 %), energy productivity (6 %), energy profitability (5 %), and 5 % lower carbon footprint over no substitution. The highest carbon footprint (0.201) was recorded under control followed by 50 % substitution of RDN through FYM (0.189). With each successive increase in N dose up to 150 kg N ha-1 to wheat, energy productivity significantly reduced and share of renewable energy inputs decreased from 25 to 13 %. Application of 100 kg N ha-1 to wheat maintained the highest grain yield (3.71 t ha-1), net energy return (105,516 MJ ha-1), and human energy profitability (223.4) over other N doses applied to wheat. Application of 50 kg N ha-1 to wheat maintained the least carbon footprint (0.091) followed by 100 kg N ha-1 (0.100). Our study indicates that system productivity as well as energy and carbon use efficiencies of transgenic cotton–wheat production system can be enhanced by inclusion of peanut as an intercrop in cotton and substitution of 25 % RDN of cotton through FYM, as well as application of 100 kg N ha-1 to succeeding wheat crop. © 2015, Springer International Publishing Switzerland.