• Authors:
    • Ruser, R.
    • Stolze, M.
    • Fliessbach, A.
    • Maeder, P.
    • Muller, A.
    • Gattinger, A.
    • Skinner, C.
    • Niggli, U.
  • Source: Science of The Total Environment
  • Volume: 468-469
  • Issue: January
  • Year: 2014
  • Summary: It is anticipated that organic farming systems provide benefits concerning soil conservation and climate protection. A literature search on measured soil-derived greenhouse gas (GHG) (nitrous oxide and methane) fluxes under organic and non-organic management from farming system comparisons was conducted and followed by a meta-analysis. Up to date only 19 studies based on field measurements could be retrieved. Based on 12 studies that cover annual measurements, it appeared with a high significance that area-scaled nitrous oxide emissions from organically managed soils are 492 +/- 160 kg CO2 eq. ha(-1) a(-1) lower than from non-organically managed soils. For arable soils the difference amounts to 497 +/- 162 kg CO2 eq. ha(-1) a(-1). However, yield-scaled nitrous oxide emissions are higher by 41 +/- 34 kg CO2 eq. t(-1) DM under organic management (arable and use). To equalize this mean difference in yield-scaled nitrous oxide emissions between both farming systems, the yield gap has to be less than 17%. Emissions from conventionally managed soils seemed to be influenced mainly by total N inputs, whereas for organically managed soils other variables such as soil characteristics seemed to be more important. This can be explained by the higher bioavailability of the synthetic N fertilisers in non-organic farming systems while the necessary mineralisation of the N sources under organic management leads to lower and retarded availability. Furthermore, a higher methane uptake of 3.2 +/- 2.5 kg CO2 eq. ha(-1) a(-1) for arable soils under organic management can be observed. Only one comparative study on rice paddies has been published up to date. All 19 retrieved studies were conducted in the Northern hemisphere under temperate climate. Further GHG flux measurements in farming system comparisons are required to confirm the results and close the existing knowledge gaps. (C) 2013 Elsevier B.V. All rights reserved.
  • Authors:
    • Carboni, G.
    • Virdis, A.
    • Sulas, L.
    • Ledda, L.
    • Deligios, P. A.
    • Cocco, D.
  • Source: ENERGIES
  • Volume: 7
  • Issue: 10
  • Year: 2014
  • Summary: This paper reports outcomes of life cycle assessments (LCAs) of three different oleaginous bioenergy chains (oilseed rape, Ethiopian mustard and cardoon) under Southern Europe conditions. Accurate data on field practices previously collected during a three-year study at two sites were used. The vegetable oil produced by oleaginous seeds was used for power generation in medium-speed diesel engines while the crop residues were used in steam power plants. For each bioenergy chain, the environmental impact related to cultivation, transportation of agricultural products and industrial conversion for power generation was evaluated by calculating cumulative energy demand, acidification potential and global warming potential. For all three bioenergy chains, the results of the LCA study show a considerable saving of primary energy (from 70 to 86 GJ.ha(-1)) and greenhouse gas emissions (from 4.1 to 5.2 t CO2.ha(-1)) in comparison to power generation from fossil fuels, although the acidification potential of these bioenergy chains may be twice that of conventional power generation. In addition, the study highlights that land use changes due to the cultivation of the abovementioned crops reduce soil organic content and therefore worsen and increase greenhouse gas emissions for all three bioenergy chains. The study also demonstrates that the exploitation of crop residues for energy production greatly contributes to managing environmental impact of the three bioenergy chains.
  • Authors:
    • Van Eerd, L. L.
    • Voroney, R. P.
    • Congreves, K. A.
  • Source: NUTRIENT CYCLING IN AGROECOSYSTEMS
  • Volume: 100
  • Issue: 3
  • Year: 2014
  • Summary: After cole crop harvest, over 400 kg N ha(-1) may remain in the field as crop residues and soil mineral N. Thus, methods to reduce potential post-harvest N losses are needed. Urea with 5 % N-15 excess was incorporated in mini-plots to produce N-15 enriched broccoli (Brassica olecerea var italica L.). The fate of above-ground crop residue-derived N (N-15(residue-above)) and below-ground residual fertilizer or root biomass N (N-15(residue-below)) were studied from broccoli harvest (Aug and Sept 2011) to spring wheat (Triticum durum L.) harvest (July 2012), with and without an amendment of used cooking oil. The N-15(residue-below) remained mostly as organic N, was not influenced by the amendment, and was resistant to post-harvest losses. With the oil amendment, soil mineral N-15(residue-above) was reduced by 19 kg ha(-1) and microbial biomass N-15(residue-above) was increased by 21 kg ha(-1) 2 weeks after broccoli harvest, indicating immobilization of N-15(residue-above) and reduced potential N losses. At spring wheat harvest, amended soil had greater total, organic, and mineral N-15(residue-above) compared to the unamended control, by 44, 43, and 0.75 kg ha(-1), respectively. The amendment increased the recovery of N-15(residue-above) in the soil total N pool by 209 % at spring wheat harvest, and it did not affect spring wheat yields or plant N-15(residue-above) content. It is possible that the amendment facilitated the incorporation of N-15(residue-above) into organic compounds, which were less susceptible to losses. Growers should consider applying used cooking oil at harvest to minimize potential N losses and to increase the soil organic N fraction.
  • Authors:
    • Cougnon, M.
    • Ruysschaert, G.
    • Vandecasteele, B.
    • Nest, T. vanden
    • Merckx, R.
    • Reheul, D.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 197
  • Year: 2014
  • Summary: The main objective of the present study was to compare fertilizer types in their ability to increase the soil organic matter content without increasing potential P leaching losses. Differences in soil organic carbon content, crop yield, P-CaCl 2, P-AL, P export by the crop and P leaching from soil supplied with three compost types, cattle slurry, farmyard manure or mineral fertilizers were compared in a 8 years field experiment with arable, vegetable and fodder crops. P leaching losses were assessed separately in a soil column leaching experiment. As expected, farmyard manure and compost are the better options to increase the soil organic carbon level. Cattle slurry and mineral fertilizers tended to produce lower crop yields. P-CaCl 2 was increased when farmyard manure was used as organic fertilizer, leading to an increased P leaching but not to an increased crop P export. Therefore it seems that the higher dissolved P concentrations in the soil solution for farmyard manure, measured as P-CaCl 2 in the soil, are a source of potential P losses. All three compost types could gradually increase soil organic carbon levels without increasing P leaching losses.
  • Authors:
    • Durlinger,B.
    • Tyszler,M.
    • Scholten,J.
    • Broekema,R.
    • Blonk,H.
  • Source: Proceedings of the 9th International Conference on Life Cycle Assessment in the Agri-Food Sector
  • Year: 2014
  • Summary: Agri-footprint is a new life cycle inventory database that focuses on the agriculture and food sector. The goal of this database is to support life cycle assessment practitioners to perform high quality assessments. The database contains a methodologically consistent dataset for a large number of crops, crop products, animal systems and animal products. These inventories can be used as secondary data in LCAs. Non-LCA models were used to calculate a wide array of elementary flows (such as land use change, water use, fertilizer application rates), to support assessment on a multitude of environmental issues. To safeguard relevance and data quality, the database will be updated regularly. As the public interest in food LCAs is expected to increase in the near future, Agri-footprint will be a helpful resource for practitioners in this field.
  • 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:
    • Fisher,S.
    • Karunanithi,A.
  • Source: Proceedings of the 9th International Conference on Life Cycle Assessment in the Agri-Food Sector
  • Year: 2014
  • Summary: Local policy makers typically do not have useful, quantitative metrics to compare environmental costs and benefits of urban vegetable production versus the large-scale commercial production in the typical grocery store supply chain. While urban agriculture has been championed as a way to address social issues such as food access and nutrition, we know relatively little about net environmental benefits, if any. The study combines a comparative life cycle assessment of vegetables with effects of direct and indirect land use change resulting from the urban vegetable production. This paper presents a methodology and selected results of scenarios of land use change due to urban vegetable production address resource use, greenhouse gas emissions, employment, and soil organic carbon. Surprisingly, urban vegetable production is not categorically favorable for each metric; several key parameters can shift the balance in favor or out of favor for either growing format, and these parameters are distinctly bottom-up.
  • Authors:
    • Putri,E. A.
    • Koido,K.
    • Dowaki,K.
  • Source: Proceedings of the 9th International Conference on Life Cycle Assessment in the Agri-Food Sector
  • Year: 2014
  • Summary: Climate change is mainly linked to greenhouse gas (GHG) emissions in which the agricultural sector occupies 14% of total emissions. In this paper, the questionnaires were implemented to investigate the effects of green bean quality including eco-burden factor and price on consumer buying decision. Also, on the estimation of eco-burden, LCA methodology was considered, and the carbon footprint of green bean in the supply chain process in Indonesia was expressed. The results showed that the total emissions (CFP) of green bean were between 4.92 and 7.38 kg-CO 2eq/kg green bean by varying farmers, and they became larger than that of Japan case (1.11 kg-CO 2eq/kg green bean). In addition, through our questionnaires on basis of the quality and price of green bean, we confirmed that the factor of quality is more significant for consumer buying decision.
  • Authors:
    • Zhou, D.
    • Wang, J.
    • Chen, Z.. L.
    • Bi, C. J.
  • Source: Pedosphere
  • Volume: 23
  • Issue: 2
  • Year: 2013
  • Summary: Soil health assessment is an important step toward understanding the potential effects of agricultural practices on crop yield, quality and human health. The objectives of this study were to select a minimum data set for soil health evaluation from the physical, chemical and biological properties and environmental pollution characteristics of agricultural soil and to develop a soil health diagnosis model for determining the soil health status under different planting patterns and soil types in Chongming Island of Shanghai, China. The results showed that the majority of the farmland soils in Chongming Island were in poor soil health condition, accounting for 48.9% of the survey samples, followed by the medium healthy soil, accounting for 32.2% of the survey samples and mainly distributed in the central and mid-eastern regions of the island. The indicators of pH, total organic carbon, microbial biomass carbon and Cd exerted less influence on soil health, while the soil salinization and nitrate accumulation under a greenhouse cropping pattern and phosphate fertilizer shortage in the paddy field had limited the development of soil health. Dichlorodiphenyltrichloroethanes, hexachlorocyclohexanes and Hg contributed less to soil health index (SHI) and showed no significant difference among paddy field, greenhouse and open-air vegetable/watermelon fields. The difference of the SHI of the three soil types was significant at P = 0.05. The paddy soil had the highest SHI values, followed by the gray alluvial soil, and the coastal saline soil was in a poor soil health condition, indicating a need to plant some salt-tolerant crops to effectively improve soil quality.
  • Authors:
    • Hernandez-Ramirez, G.
    • Giltrap, D.
    • Kim, D.-G.
  • Source: Plant and Soil
  • Volume: 373
  • Issue: 1-2
  • Year: 2013
  • Summary: This study aimed at better characterising background nitrous oxide (N2O) emissions (BNE) in agricultural and natural lands. We compiled and analysed field-measured data for annual background N2O emission in agricultural (BNEA) and natural (BNEN) lands from 600 and 307 independent experimental studies, respectively. There were no significant differences between BNEA (median: 0.70 & mean: 1.52 kg N2O -aEuro parts per thousand N ha(-1) yr(-1)) and BNEN (median:0.31 & mean:1.75 kg N2O -aEuro parts per thousand N ha(-1) yr(-1)) (P > 0.05). A simultaneous comparison across all BNEA and BNEN indicated that BNEs from riparian, vegetable crop fields and intentional fallow areas were significantly higher than from boreal forests (P < 0.05). Correlation and regression analyses supported the underlying associations of soil organic carbon (C), nitrogen (N), pH, bulk density (BD),and/or air temperature (AT) with BNEs to a varying degree as a function of land-use or ecosystem type (Ps < 0.05). Although overall BNEN tended to be lower than BNEA on median basis, results in general suggest that land-use shifts between natural and managed production systems would not result in consistent changes in BNE.