• Authors:
    • Al-Mansour, F.
    • Jejcic, V.
  • Source: Proceedings of the 42nd International Symposium on Agricultural Engineering, Actual Tasks on Agricultural Engineering, Opatija, Croatia, 25-28 February, 2014
  • Year: 2014
  • Summary: An analysis of the carbon footprint of conventional, integrated and organic crop production, and three sizes of farms was made. Conventional tillage and direct seeding were used in mentioned production systems. For the analysis of the carbon footprint, CO 2 emissions from fossil fuel (direct energy) consumed in the process of production of corn (for silage and grain), wheat, rapeseed, and sunflower were used. In addition to emissions from fossil fuels used in the production of mentioned crops, greenhouse gas emissions resulting from the use of organic and mineral fertilizers in the production and converted to CO 2 equivalents were also used. In the case of conventional production mineral fertilizers were used, in integrated production combination of mineral fertilizers and organic fertilizers and in organic production only organic fertilizer was used. The sum of emissions arising from fossil fuel use and emissions from fertilizers used in the cultivation process, make final emission from crop production. It was estimated that the emissions of CO 2/t of yields in conventional and integrated production are about the same. In organic production emissions of CO 2/t of yields are higher in comparison with emissions CO 2/t of yields in conventional and integrated farming. CO 2 emissions in conventional and organic production (CO 2/t of yield) are in the following proportions: corn for grain 1:1.34, corn for silage 1:1.52, wheat 1:1.53, rapeseed 1:1.47 and sunflower 1:1.2 (the higher is the number of organic production).
  • Authors:
    • Zimmerman, A. R.
    • Lal, R.
    • Mukherjee, A.
  • Source: SOIL SCIENCE
  • Volume: 179
  • Issue: 7
  • Year: 2014
  • Summary: While biochar research has progressed, there is relatively little field-scale data over time, which constrains our understandings of biochar's "true" effects on soil quality and our ability to make appropriate recommendations to users, especially in comparison to other amendments. Thus, this study compares 2 successive years' field-scale soil data with biochar and other amendments added to a scalped silty clay loam soil at an application rate of 0.5%. None of the amendments significantly affected any of the measured soil physicochemical properties and greenhouse gas emissions even after 1.5 years of field aging. However, some of the measured soil properties were significantly changed after the second year compared with those of the first year. On temporal scale, soil electrical conductivity and penetration resistance significantly increased under most treated soils, and soil available water capacity significantly increased only under biochar. Although no differences in soil properties were detected, there was a trend toward higher corn dry grain and biomass yields under biochar compared with those of the control. Biochar was able to reduce N 2O emissions from soil, only in the first year, whereas gaseous emissions were not different from control in the rest of the experiment. Thus, the findings of this study suggest that the improvements in soil fertility due to biochar amendment were not because of changes in most of the observed physical properties of the soil, but some other effects (changes in microbial community or nutrient additions) may have controlled the crop yield. In addition, these data demonstrate that selected amendment application rate of 0.5% (wt/wt) was not sufficient to cause significant changes in most observed physical properties beyond 1.5 years of field aging, suggesting additional research using higher rate of application.
  • Authors:
    • Tilvikiene, V.
    • Kadziuliene, Z.
    • Venslauskas, K.
    • Navickas, K.
    • Nekrosius, A.
  • Source: ZEMDIRBYSTE-AGRICULTURE
  • Volume: 101
  • Issue: 3
  • Year: 2014
  • Summary: The research was aimed to investigate the energy biomass productivity and biogas production from silage of different perennial grasses with evaluation of greenhouse gas emissions through the entire process from biomass cultivation to processing. The experiments with perennial grasses - cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Scherb.) and reed canary grass (Phalaris arundinacea L.) were carried out at Institute of Agriculture, Lithuanian Research Centre for Agriculture and Forestry in 2008-2010. The swards were grown in an Endocalcari-Endohypogleyic Cambisol(CMg-n-w-can), which contained: organic carbon 1.61-1.75%, available P 145-224 mg kg(-1) and K 128-158 mg kg(-1), soil pH ranging between 6.7-7.0. The three perennial grass species with varying yields of biomass were used to ensure a steady operation of the selected biogas plant of 500 kW(e) electric power. The different quantities of biomass feedstock and varying energy input are required for such biogas plant. Therefore all data correspond to a biogas cogeneration plant of 500 kWe electric power. Required land area for the same amount of energy produced depends on species of perennial grasses, rates of fertilization and number of cuts. These results mainly depended on the biomass productivity and biogas yield from dry mass. Biomass yield from dry matter in the first year of use of tall fescue cut twice per vegetation season was higher compared to that cut three times, while cocksfoot and reed canary grass yielded better cut three times compared to cut twice. The highest yield was obtained in tall fescue swards cut twice and fertilized with N-180. The total balance of greenhouse gas emissions showed their mitigation and ranged from 0.206 to 0.298 kg CO2 eq kWh(-1).
  • Authors:
    • Brown, K. M.
    • Chimungu, J. G.
    • Lynch, J. P.
  • Source: PLANT PHYSIOLOGY
  • Volume: 166
  • Issue: 4
  • Year: 2014
  • Summary: The objective of this study was to test the hypothesis that large cortical cell size (CCS) would improve drought tolerance by reducing root metabolic costs. Maize ( Zea mays) lines contrasting in root CCS measured as cross-sectional area were grown under well-watered and water-stressed conditions in greenhouse mesocosms and in the field in the United States and Malawi. CCS varied among genotypes, ranging from 101 to 533 m 2. In mesocosms, large CCS reduced respiration per unit of root length by 59%. Under water stress in mesocosms, lines with large CCS had between 21% and 27% deeper rooting (depth above which 95% of total root length is located in the soil profile), 50% greater stomatal conductance, 59% greater leaf CO 2 assimilation, and between 34% and 44% greater shoot biomass than lines with small CCS. Under water stress in the field, lines with large CCS had between 32% and 41% deeper rooting (depth above which 95% of total root length is located in the soil profile), 32% lighter stem water isotopic ratio of 18O to 16O signature, signifying deeper water capture, between 22% and 30% greater leaf relative water content, between 51% and 100% greater shoot biomass at flowering, and between 99% and 145% greater yield than lines with small cells. Our results are consistent with the hypothesis that large CCS improves drought tolerance by reducing the metabolic cost of soil exploration, enabling deeper soil exploration, greater water acquisition, and improved growth and yield under water stress. These results, coupled with the substantial genetic variation for CCS in diverse maize germplasm, suggest that CCS merits attention as a potential breeding target to improve the drought tolerance of maize and possibly other cereal crops.
  • Authors:
    • Zhao, Y.
    • Gao, J.
    • Liu, J.
  • Source: Acta Pedologica Sinica
  • Volume: 51
  • Issue: 6
  • Year: 2014
  • Summary: Applying biochar to soils may cause a win-win situation resulting in C sequestration and improvement of soil fertility and soil physical quality, depending on soil moisture condition, soil temperature and soil C/N ratio. An in-lab incubation experiment, laid out in quadratic general spinning design, was conducted to investigate effects of application of maize stalk and biochar made from maize stalk on N transformation in and N 2O emission from Loessal soil. Results show that in the soil applied with maize stalk, net nitrogen mineralization was influenced mainly by content of organic carbon, and then by contents of water and nitrogen, but in the soil applied with biochar, it was mainly by content of nitrogen and then by contents of water and organic carbon. The difference between the two carbon sources in effect on net N mineralization was extremely significant ( p<0.01). Compared with maize stalk, biochar increased soil NO 3--N and NH 4+-N concentrations, and significantly decreased N 2O emission. In the soil applied with biochar, the concentration of inorganic nitrogen changed slowly during the entire incubation period, while in the soil applied with maize stalk, it did drastically in the first two weeks of the incubation. Hence, it is obvious that application of biochar is conducive to reduction of emission of the greenhouse gas, N 2O.
  • Authors:
    • Jin, D. S.
    • Lu, C. D.
    • Zhang, Q.
    • Gao, C. H.
    • Li, J. H.
  • Source: Meteorological and Environmental Research
  • Volume: 5
  • Issue: 4
  • Year: 2014
  • Summary: Taking a three-year fertilization trial in mine reclamation soil from Shanxi Province, China as an example, the effects of different fertilization treatments on soil carbon storage and carbon fixation by corn were studied in this paper. Four treatments were designed in the experiment, including fertilizer (F), organic manure (M), half organic manure plus half fertilizer (FM) and control (CK). The results showed that fertilization had certain roles in increasing organic carbon storage of mine reclamation soil, and the application of single or combined organic and inorganic fertilizers had the most remarkable influence. Meanwhile, the treatment of single or combined organic and inorganic fertilizers could improve the carbon fixation capacity of corn prominently, and increased soil organic matter input. Thus, the application of organic manure or combined organic and inorganic fertilizer has great contribution to enhancing soil carbon sink and sustainable development of agriculture. However, the combined application of organic and inorganic fertilizer is the best choice for agricultural field based on economic consideration.
  • Authors:
    • Shiekhdavoodi, M. J.
    • Sami, M.
    • Almassi, M.
  • Source: Acta Agriculturae Slovenica
  • Volume: 103
  • Issue: 2
  • Year: 2014
  • Summary: In this study, the net balance of greenhouse gas (GHG) emission and energy of wheat and maize production systems in two farms in Khuzestan province of Iran was assessed. The results showed that totally wheat farming is more efficient than maize farming in terms of energy and CO2-eq indexes. The total energy requirement for maize and wheat farming was 92560.24 MJ ha-1 and 39624.15 MJ ha-1, which caused the emission of 20191.47 and 7541.04 kg CO2-equivalent per hectare in maize and wheat farms respectively. Electricity, fertilizers and fuel were the most important pollutants of environment in terms of energy and gas emission in both farms. Theses inputs consumed 55.52, 22.62 and 6.44 % of total energy of maize and 47.32, 21.19 and 9.01 % of total energy of wheat farm and were responsible for the 88.60, 8.79 and 2.03 % of CO2-equivalent in maize and 86.54, 9.54 and 3.24 % of CO2-equivalent in wheat farms respectively. The results of this study also showed that the enhancement of 60.74 and 27.02 % in energy ratio and 46.06 and 27.87 % in CO2-eq index in maize and wheat farming can be expected using simple improving scenarios.
  • Authors:
    • Bjornsson,L.
    • Prade,T.
  • Source: Proceedings of the 9th International Conference on Life Cycle Assessment in the Agri-Food Sector
  • Year: 2014
  • Summary: In an analysis of climate effects, increased soil organic carbon will have a dual effect due to both increased soil fertility and carbon sequestration. Even so, soil carbon changes are neglected in many crop production LCAs. In the present study, the introduction of grass-clover crops in cereal-dominated crop production was evaluated. The grass-clover crops were used for biogas production, and the digested residue was recycled to the farm as biofertilizer. A shift from the cereal-dominated crop rotation to integrated production of food crops and one or two years of grass-clover crops used as biogas feedstock would result in avoided emissions of 2-3 t CO 2-eq. ha -1 a -1. Integrated food and energy crop production would in this case improve soil organic carbon content at the same time as resulting in considerably decreased greenhouse gas emissions from the cultivation system.
  • Authors:
    • Escobar,N.
    • Ribal,F. J.
    • Clemente,G.
    • Sanjuan,N.
  • Source: Proceedings of the 9th International Conference on Life Cycle Assessment in the Agri-Food Sector
  • Year: 2014
  • Summary: Imported biodiesel has accounted for a large share of the total amount consumed in Spain, the main supplier of which was Argentina at least until anti-dumping duties on biodiesel imports from this origin were approved by the European Commission in November 2013. A consequential LCA is carried out in the present study to compare this pathway, which was the prevailing one until almost 2014, with the alternative of using domestic biodiesel from Used Cooking Oil (UCO). System expansion is performed in order to take the indirect functions of both systems into account, functions arising from interactions between co-products (protein meals) in the animal feed market. The marginal suppliers of these co-products in the international market are identified and emissions from direct and indirect Land Use Change (LUC) are calculated. When they are not considered, imported soybean biodiesel leads to lower GHG emissions, due to the carbon uptake by biomass. However, when global LUC is taken into account, UCO biodiesel generates a much lower impact, because it causes a contraction in the area diverted to biofuel feedstock production in other parts of the world. The results underline the importance of considering emissions from LUC when comparing biodiesel alternatives and, thus, interactions in the global market must be addressed.
  • Authors:
    • Fumagalli,M.
  • Source: Italian Journal of Agrometeorology
  • Volume: 20
  • Issue: 1
  • Year: 2014
  • Summary: Intensive maize production in Lombardy region (northern Italy) is widespread and requires big amounts of input, especially nitrogen (N), thus leading to potential environmental risks. Starting from farm survey data the current work aims to evaluate how alternative N management options for reducing losses can be effective in climate change mitigation. Under current management (ACT) of typical continuous maize cropping systems across the region, the greenhouse gases (GHG) emissions from the production of inorganic fertilisers and from direct and indirect N2O released after N application accounted for, on average, 67% of the total GHG emissions. The adoption of the best N management plans (FERT scenario), reduced GHG emissions and C-footprint (expressed per unit of agricultural product) by 27 and 26%, respectively. Furthermore, the double cropping system (two crops harvested in 12 months - ROT scenario) strongly increased GHG emissions in comparison with the only cultivation of a summer crop. However, the high productivity of this system, led to a C-footprint lower than the ACT one and still higher than the FERT one. The current work highlights the opportunities for carbon mitigation offered by changes on field N management, without significantly impact the yield. © 2015, Patron Editore S.r.l. All rights reserved.