• Authors:
    • Brandt, S. A.
    • Malhi, S. S.
    • Huang, G.
    • Liang, C.
    • Gan, Y.
    • Katepa-Mupondwa, F.
  • Source: The International Journal of Life Cycle Assessment
  • Volume: 17
  • Issue: 1
  • Year: 2012
  • Summary: Best agricultural practices can be adopted to increase crop productivity and lower carbon footprint of grain products. The aims of this study were to provide a quantitative estimate of the carbon footprint of selected oilseed crops grown on the semiarid northern Great Plains and to determine the effects of N fertilization and environments on the carbon footprint. Five oilseed crops, Brassica napus canola, Brassica rapa canola, Brassica juncea canola, B. juncea mustard, and Sinapis alba mustard, were grown under the N rates of 0, 25, 50, 100, 150, 200, and 250 kg N ha(-1) at eight environsites (location x year combinations) in Saskatchewan, Canada. Straw and root decomposition and various production inputs were used to calculate greenhouse gas emissions and carbon footprints. Emissions from the production, transportation, storage, and delivery of N fertilizer to farm gates accounted for 42% of the total greenhouse gas emissions, and the direct and indirect emission from the application of N fertilizer in oilseed production added another 31% to the total emission. Emissions from N fertilization were nine times the emission from the use of pesticides and 11 times that of farming operations. Straw and root decomposition emitted 120 kg CO(2)eq ha(-1), contributing 10% to the total emission. Carbon footprint increased slightly as N rates increased from 0 to 50 kg N ha(-1), but as N rates increased from 50 to 250 kg N ha(-1), carbon footprint increased substantially for all five oilseed crops evaluated. Oilseeds grown at the humid Melfort site emitted 1,355 kg CO(2)eq ha(-1), 30% greater than emissions at the drier sites of Scott and Swift Current. Oilseeds grown at Melfort had their carbon footprint of 0.52 kg CO(2)eq kg(-1) of oilseed, 45% greater than that at Scott (0.45 kg CO(2)eq kg(-1) of oilseed), and 25% greater than that at Swift Current (0.45 kg CO(2)eq kg(-1) of oilseed). Carbon footprint of oilseeds was a function of the rate of N fertilizer, and the intensity of the functionality varied between environments. Key to lower carbon footprint in oilseeds is to improve N management practices.
  • Authors:
    • Ruiz R., R.
    • Henson, I.
    • Romero, H.
  • Source: Agronomia Colombiana
  • Volume: 30
  • Issue: 3
  • Year: 2012
  • Summary: Colombia is currently the world's fifth largest producer of palm oil and the largest producer in South and Central America. It has substantial areas of land that could be used for additional oil palm production and there is considerable scope for increasing yields of existing planted areas. Much of the vegetation on land suitable for conversion to oil palm has a low biomass, and so establishing oil palm plantations on such land should lead to an increase in carbon stock, thereby counteracting greenhouse gas (GHG) emissions responsible for global warming. The first part of this study examines changes in carbon stock in Colombia resulting from expansion of oil palm cultivation together with factors (offsets) that act to minimize carbon emissions. The results are subsequently used to construct a net GHG balance.
  • Authors:
    • Romero, H.
    • Ruiz R., R.
    • Henson, I.
  • Source: Agronomia Colombiana
  • Volume: 30
  • Issue: 3
  • Year: 2012
  • Summary: In the preceding paper we examined carbon sequestration in oil palm plantations and in mill products and by-products as part of a study of the greenhouse gas balance of palm oil production in Colombia, showing how this has changed over time. Here, we look at the opposing processes of greenhouse gas (GHG) emission and calculate the resulting net carbon budget for the industry. The main emission sources, in decreasing order of magnitude, assessed using "default" or "most probable" options, were found to be land use change (40.9% of total), mill methane production (21.4%), direct use of fossil fuel (18.5%), indirect use of fossil fuel (11.9%) and nitrous oxide production (7.3%). The total (gross) emissions, expressed in carbon equivalents (Ceq.), were less than the amount of sequestered carbon, resulting in a positive net Ceq. balance. All oil palm growing regions showed a net gain with the exception of the western zone, where emissions due to land-use change were judged to be substantial. Of the 11 alternative scenarios tested, only three resulted in Ceq. balances lower than the default and only two gave a negative balance.
  • Authors:
    • Harmand, J.
    • Henault, C.
    • Skiba, U.
    • Blanchart, E.
    • Hergoualc'h, K.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 148
  • Year: 2012
  • Summary: Agroforestry represents an opportunity to reduce CO2 concentrations in the atmosphere by increasing carbon (C) stocks in agricultural lands. Agroforestry practices may also promote mineral N fertilization and the use of N-2-fixing legumes that favor the emission of non-CO2 greenhouse gases (GHG) (N2O and CH4). The present study evaluates the net GHG balance in two adjacent coffee plantations, both highly fertilized (250 kg N ha(-1) year(-1)): a monoculture (CM) and a culture shaded by the N-2-fixing legume tree species Inga densiflora (CIn). C stocks, soil N2O emissions and CH4 uptakes were measured during the first cycle of both plantations. During a 3-year period (6-9 years after the establishment of the systems), soil C in the upper 10 cm remained constant in the CIn plantation (+0.09 +/- 0.58 Mg C ha(-1) year(-1)) and decreased slightly but not significantly in the CM plantation (-0.43 +/- 0.53 Mg C ha(-1) year(-1)). Above-ground carbon stocks in the coffee monoculture and the agroforestry system amounted to 9.8 +/- 0.4 and 25.2 +/- 0.6 Mg C ha(-1), respectively, at 7 years after establishment. C storage rate in the phytomass was more than twice as large in the CIn compared to the CM system (4.6 +/- 0.1 and 2.0 +/- 0.1 Mg C ha(-1) year(-1), respectively). Annual soil N2O emissions were 1.3 times larger in the CIn than in the CM plantation (5.8 +/- 0.5 and 4.3 +/- 0.3 kg N-N2O ha(-1) year(-1), respectively). The net GHG balance at the soil scale calculated from the changes in soil C stocks and N2O emissions, expressed in CO2 equivalent, was negative in both coffee plantations indicating that the soil was a net source of GHG. Nevertheless this balance was in favor of the agroforestry system. The net GHG balance at the plantation scale, which includes additionally C storage in the phytomass, was positive and about 4 times larger in the CIn (14.59 +/- 2.20 Mg CO2 eq ha(-1) year(-1)) than in the CM plantation (3.83 +/- 1.98 Mg CO2 eq ha(-1) year(-1)). Thus converting the coffee monoculture to the coffee agroforestry plantation shaded by the N-2-fixing tree species I. densiflora would increase net atmospheric GHG removals by 10.76 +/- 2.96 Mg CO2 eq ha(-1) year(-1) during the first cycle of 8-9 years. (c) 2011 Elsevier B.V. All rights reserved.
  • Authors:
    • Cervantes-Santiago, F.
    • Reyes-Varela, V.
    • Conde, E.
    • Fernandez-Luqueno, F.
    • Juarez-Rodriguez, J.
    • Botello-Alvarez, E.
    • Cardenas-Manriquez, M.
    • Dendooven, L.
  • Source: Journal of Plant Nutrition
  • Volume: 35
  • Issue: 4
  • Year: 2012
  • Summary: Sludge derived from cow manure anaerobically digested to produce biogas (methane; CH4) was applied to maize (Zea mays L.) cultivated in a nutrient-low, alkaline, saline soil with electrolytic conductivity 9.4 dS m(-1) and pH 9.3. Carbon dioxide (CO2) emission increased 3.1 times when sludge was applied to soil, 1.6 times when cultivated with maize and 3.5 times in sludge-amended maize cultivated soil compared to the unamended uncultivated soil (1.51 mg C kg(-1) soil day(-1)). Nitrous oxide (N2O) emission from unamended soil was -0.0004 mu g nitrogen (N) kg(-1) soil day(-1) and similar from soil cultivated with maize (0.27 mu g N kg(-1) soil day(-1)). Application of sludge increased the N2O emission to 4.59 mu g N kg(-1) soil day(-1), but cultivating this soil reduced it to 2.42 mu g N kg(-1) soil day(-1). It was found that application of anaerobic digested cow manure stimulated maize development in an alkaline saline soil and increased emissions of CO2 and N2O.
  • Authors:
    • de Barros Viana Hissa, L.
    • Soares-Filho, B. S.
    • Costa, M. H.
    • Leite, C. C.
  • Source: Global Biogeochemical Cycles
  • Volume: 26
  • Issue: 2
  • Year: 2012
  • Summary: The evaluation of impacts of land use change is in general limited by the knowledge of past land use conditions. Most publications on the field present only a vague description of the earlier patterns of land use, which is usually insufficient for more comprehensive studies. Here we present the first spatially explicit reconstruction of historical land use patterns in Brazil, including both croplands and pasturelands, for the period between 1940 and 1995. This reconstruction was obtained by merging satellite imagery with census data, and provides a 5' x 5' yearly data set of land use for three different categories (cropland, natural pastureland and planted pastureland) for Brazil. The results show that important land use changes occurred in Brazil. Natural pasture dominated in the 1950s and 1960s, but since the beginning of 1970s it has been gradually replaced by planted pasture, especially in southeast and center west of Brazil. The croplands began its expansion in the 1960s reaching extensive areas in almost all states in 1980. Carbon emissions from historical land use changes were calculated by superimposing a composite biomass map on grids of a weighted average of the fractions of the vegetation types and the replacement land uses. Net emissions from land use changes between 1940 and 1995 totaled 17.2 +/- 9.0 Pg-C (90% confidence range), averaging 0.31 +/- 0.16 Pg-C yr(-1), but reaching up to 0.47 +/- 0.25 Pg-C yr(-1) during the 1960s and through 1986-1995. Despite international concerns about Amazon deforestation emissions, 72% of Brazil's carbon emissions during the period actually came from deforestation in the Atlantic Forest and Cerrado biomes. Brazil's carbon emissions from land use change are about 11 times larger than its emissions from fossil fuel burning, although only about 18.1% of the native biomass has been lost due to agricultural expansion, which is similar to the global mean (17.7%).
  • Authors:
    • Rao, K.
    • Laxminarayana, K.
    • Nedunchezhiyan, M.
    • Satapathy, B.
  • Source: Acta Agronomica Hungarica
  • Volume: 59
  • Issue: 2
  • Year: 2011
  • Summary: A field experiment was conducted at the Regional Centre of the Central Tuber Crops Research Institute, Dumduma, Bhubaneswar for three consecutive years (2006-2008) under rainfed conditions on Alfisols to quantify the effects of strip intercropping on crop yields and yield components. A significantly higher yield was obtained from sweet potato ( Ipomoea batatas L.) border rows when pigeonpea ( Cajanus cajan (L.) Millsp.) was intercropped. Analyses of sweet potato yield components indicated that the number of roots/plant, root length and root diameter were significantly higher in border rows when rice ( Oryza sativa L.), finger millet ( Eleusine coracana L.) and pigeonpea were used as intercrop compared to monoculture sweet potato. The number of tubers/plant of sweet potato in border rows was significantly lower when maize ( Zea mays L.) was intercropped, but the root length and root diameter were found to increase compared to sole sweet potato. The yields of rice, finger millet, maize and pigeonpea in inside rows in strip cropping were a little higher than in monoculture. The yield difference was mainly due to an increase in the number of seeds/panicle or cob. Sweet potato was the dominant crop when grown with rice or finger millet, but it was the subordinate crop when grown along with maize or pigeonpea. Sweet potato yields were consistently higher in strip intercropping than in monoculture when calculated across all the strips on an equal area basis. A strip intercropping system involving sweet potato+pigeonpea resulted in a higher land equivalent ratio (1.31) and net return ($623.9) compared to the other forms of intercropping and to monocropping.
  • Authors:
    • Alam, M.
    • Islam, M.
    • Bashar, M.
    • Rahman, M.
  • Source: International Journal of Sustainable Agricultural Technology
  • Volume: 7
  • Issue: 4
  • Year: 2011
  • Summary: An experiment was conducted at farmers' field at Kapasia upazila of Gazipur district in Bangladesh during 2002-2003 cropping season to the profitability of chewing sugarcane intercropping in Modhupur Tract soils of Bangladesh. Three selected winter crops namely, potato, gardenpea and tomato as intercrops were grown with chewing sugarcane promising clone Amrita. The highest tiller production at 150 DAT was recorded in T4 (Paired row cane+Tomato) treatment (281.07*10 -3 ha -1) and lowest in T1 (Paired row cane) treatment (248.43*10 -3 ha -1). The highest millable cane, highest cane yield and highest Brix (%) were obtained in T2 (Paired row cane+Potato) treatment. The highest price of millable cane, highest price of intercrop, highest total price, highest equivalent millable cane, highest total adjusted millable cane, highest total production cost, highest gross return and highest gross margin were obtained in T2 (Paired row cane+Potato) treatment. The highest benefit cost ratio (BCR) was found in T2 (Paired row cane+Potato) treatment (10.05) and lowest in T1 (paired row cane) treatment (8.95). Results indicated that strong possibilities of chewing sugarcane Amrita with potato intercrop cultivation in Gazipur district of Bangladesh.
  • Authors:
    • Amarasekera, P.
    • Sangakkara, U. R.
    • Stamp, P.
  • Source: Acta Agronomica Hungarica
  • Volume: 59
  • Issue: 2
  • Year: 2011
  • Summary: Maize is the most important upland cereal in tropical Asia, grown in both major and minor seasons under rainfed conditions. Due to the inadequate rainfall in the minor season, the crop is subjected to water stress, and irrigation helps to produce high yields. Smallholders who grow maize on flat beds in their allotments often use surface flood irrigation whenever irrigation water is available, which leads in most instances to inefficient use of this valuable resource. A field study was carried out over two minor seasons in Sri Lanka to determine the impact of different schedules of irrigation, developed on the basis of time intervals (3-, 7-, 14- or 21-day intervals or no irrigation as a control), which can easily be practised by smallholders, on the root development, shoot growth, seed yield and water use efficiency of maize. Irrigation at 3-day intervals produced fine roots in the top layers of the soil. Increasing the time interval between irrigation schedules to 7, 14 or 21 days reduced the percentage of fine roots, but developed more, heavier roots in the lower soil layers, as determined by root length densities (RLD) and root weight densities (RWD). Longer irrigation intervals or lack of irrigation resulted in a smaller number of heavier roots in the soil profile. The leaf water potential was affected to a greater degree than shoot water content or relative water content. The seed yield and harvest index were highest when maize was irrigated at 7-day intervals. In contrast, irrigation water use efficiency (IWUE) was highest at an irrigation interval of 14 days. The potential for optimizing water use in surface irrigation in flat beds while obtaining high yields in a tropical Asian minor season, when maize is subjected to moisture stress under smallholding conditions, is presented on the basis of this study.
  • Authors:
    • Cella, A. J. S.
    • Ferraz, E. de C.
    • Barros, H. B.
    • Santos, E. R. dos
    • Capone, A.
    • Santos, A. F. dos
    • Fidelis, R. R.
  • Source: Revista Ceres
  • Volume: 58
  • Issue: 6
  • Year: 2011
  • Summary: The genetic diversity is one of the most important parameters evaluated by plant breeders in the early stages of a genetic improvement program. The objective of this paper was to evaluate the genetic divergence by means of multivariate techniques, among 48 soybean genotypes grown in irrigated lowland in the State of Tocantins, in order to select parents of hybrids for the production of oil and meal, as well as varieties of the panel, intended for human consumption. The experiment was conducted in the county Formoso do Araguaia - Tocantins, Brazil, in the cultivation of irrigated lowland, in the inter-cropping 2010. The experimental design was a randomized block with four replications. There was observed variability among the genotype tested. The Tocher's method, UPGMA and Canonic Variables agreed among themselves, and found four distinct groups. The following hybrids are promising for the production of soybean oil and meal for the M-Soy 8766, M-Soy 9144, A-7002 and M-soy 9056 with Amaralina RR crosses between and M-Soy 8766, M-Soy 9144 and Amaralina RR with BRSMG 790A, BRS 257, BRS 216 and BRS 213, are listed in order especially soybeans for human consumption.