• Authors:
    • Koledoye, G. F.
    • Elhamoly, A. I. M. A.
    • Kamel, A.
  • Source: Journal of Agricultural & Food Information
  • Volume: 15
  • Issue: 3
  • Year: 2014
  • Summary: This study identified and prioritized the in-service training needs of Egyptian extension specialists in organic farming. The Krejcie and Morgan sampling table was used to sample 77 agricultural extension specialists (SMSs). Based on the Borich needs assessment model, 16 competencies were used to assess the training needs of SMSs in organic farming using the perceived levels of importance. The training needs were analyzed and ranked using mean weighted discrepancy scores (MWDS). "Appropriate amounts of bio-fertilizers" (MWDS=39.59) and "Steps of utilizing bio-fertilizers" (MWDS=32.97) were the top two competencies. The Ministry of Agriculture can use these findings as the basis of training programs for SMSs.
  • Authors:
    • Osmond, D.
    • Hoyt, G.
    • Edgell, J.
    • Grossman, J.
    • Larsen, E.
    • Hu, S.
  • Source: SOIL & TILLAGE RESEARCH
  • Volume: 139
  • Year: 2014
  • Summary: Topsoil losses through surface runoff have severe implications for farmers, as well as surrounding ecosystems and waterbodies. However, integrating management systems that enhance soil organic matter (SOM) can stabilize the soil surface from erosion. Little is known about how differences in both tillage and cropping system management affect carbon and subsequent sediment losses in horticultural fields, particularly in the humid climate of the southeast. Research was conducted in the Appalachian Mountains in Mills River, NC on a fine-sandy loam Acrisol from 2010 to 2012 on long-term plots established in 1994. Project objectives included to: (1) quantify labile and total organic matter based on tillage and cropping system practices, (2) determine if relationships exist between SOC ad sediment losses, and (3) determine long-term management and tillage impacts on total organic matter lost via runoff. We hypothesized that organic management and reduced tillage would lead to increased soil carbon, which subsequently reduce losses as soil is stabilized. Organic no tillage and conventional till treatments contained on average 14.34 and 6.80gkg-1 total carbon (TC) respectively, with the organic no till treatments containing twice the quantity of TC and light fraction particulate organic matter (LPOM) in the upper 15cm as compared with the conventionally tilled treatments, and four times the quantity of microbial biomass carbon (MBC). LPOM and HPOM, the heavier fraction of POM, did not differ in the organic till and conventional no till treatments.Data support our hypothesis that organic production in combination with no tillage increases C pools (both total and labile) as compared with tilled conventional plots. However, organic no till treatments produced sweet corn (Zea mays var. saccharata) yields less than 50% of that of conventional treatments, attributed to weed competition and lack of available N. No tillage treatments lost two to four times less soil C via surface runoff than tilled systems. Additionally, we found that as total soil C increased, suspended solids lost through surface runoff decreased. Overall, our results indicate tillage to be an important factor in enhancing soil C and decreasing soil loss through surface runoff. © 2014 Elsevier B.V.
  • Authors:
    • Hermansen, J. E.
    • Chirinda, N.
    • Olesen, J. E.
    • Meyer-Aurich, A.
    • Knudsen, M. T.
  • Source: Journal of Cleaner Production
  • Volume: 64
  • Issue: February
  • Year: 2014
  • Summary: Many current organic arable agriculture systems are challenged by a dependency on imported livestock manure from conventional agriculture. At the same time organic agriculture aims at being climate friendly. A life cycle assessment is used in this paper to compare the carbon footprints of different organic arable crop rotations with different sources of N supply. Data from long-term field experiments at three different locations in Denmark were used to analyse three different organic cropping systems ('Slurry', 'Biogas' and 'Mulching'), one conventional cropping system ('Conventional') and a "No input" system as reference systems. The 'Slurry' and 'Conventional' rotations received slurry and mineral fertilizer, respectively, whereas the 'No input' was unfertilized. The 'Mulching' and 'Biogas' rotations had one year of grass-clover instead of a faba bean crop. The grass-clover biomass was incorporated in the soil in the 'Mulching' rotation and removed and used for biogas production in the 'Biogas' rotation (and residues from biogas production were simulated to be returned to the field). A method was suggested for allocating effects of fertility building crops in life cycle assessments. The results showed significantly lower carbon footprint of the crops from the 'Biogas' rotation (assuming that biogas replaces fossil gas) whereas the remaining crop rotations had comparable carbon footprints per kg cash crop. The study showed considerable contributions caused by the green manure crop (grass-clover) and highlights the importance of analysing the whole crop rotation and including soil carbon changes when estimating carbon footprints of organic crops especially where green manure crops are included. (C) 2013 Elsevier Ltd. All rights reserved.
  • Authors:
    • Leu, A.
  • Source: Acta Horticulturae
  • Issue: 1018
  • Year: 2014
  • Summary: Soil carbon sequestration using current organic land management methods has the potential to mitigate a substantial proportion of global greenhouse gas emissions. A published peer review study by the Research Institute of Organic Agriculture (FiBL), found that organic farming practices remove 2,000 kg of carbon dioxide from the air each year and sequester it in a hectare of farmland. There is compelling data that significantly higher levels of CO 2 sequestration can be achieved. The Rodale studies have demonstrated that good organic practices can sequester 3596.6 kg of CO 2 per hectare year for around 30 years however when compost is added this increases to 8220.8 kg of CO 2 per hectare year. Other studies show that increasing the levels of soil carbon improves the resilience of farming systems to the increased frequency extreme weather events, such as droughts and heavy rains, that are linked to climate change.
  • Authors:
    • BaoHai, W.
    • Ying, L.
  • Source: Journal of Agricultural Science and Technology (Beijing)
  • Volume: 16
  • Issue: 2
  • Year: 2014
  • Summary: Since entering into the 21st century, greenhouse gas emissions have led to the continued global warming. Low-carbon environment protection has been raised on the agenda. The development of low-carbon eco-agriculture has become an effective way to solve China's agricultural resources exhaustion, to curb environment deterioration, and to achieve the sustainable development of China's agriculture. In 2009, the Yellow River Delta Efficient Ecological Economic Zone rose to the national strategy. Low-carbon agriculture has become the theme for the development of modern agriculture in the Yellow River Delta. This paper analyzed the necessity for the Yellow River Delta to develop Low-Carbon Eco-agriculture. Combining with the status quo of natural resources and environment in this area, and the requirement for developing Low-Carbon agriculture, the paper put up 5 models suitable for the Yellow River Delta to develop Low-Carbon Eco-agriculture. At the same time, a series of suggestions were put forward based on these models.
  • Authors:
    • Heydarpour, E.
    • Mahmoodabadi, M.
  • Source: International Agrophysics
  • Volume: 28
  • Issue: 2
  • Year: 2014
  • Summary: Soil organic carbon is one of the most important soil components, which acts as a sink for atmospheric CO2. This study focuses on the effect of different methods of organic matter application on the soil organic carbon sequestration in a 4-month experiment under controlled greenhouse conditions. Three rates of straw residue and farmyard manure were added to uncultivated and cropland soils. Two treatments of straw residue and farmyard manure incorporation were used into: a soil surface layer and 0-20 cm soil depth. The result showed that the application of organic matter, especially the farmyard manure incorporation led to a significant increase in the final soil organic carbon content. Higher amounts of soil organic carbon were stored in the cropland soil than in the uncultivated soil. On average, the soil surface layer treatment caused a higher sequestration of soil organic carbon compared to the whole soil depth treatment. If higher rates of organic matter were added to the soils, lower carbon sequestration was observed and vice versa. The result indicated that the carbon sequestration ranged farmyard manure > straw residue and cropland soil > uncultivated soil. The findings of this research revealed the necessity of paying more attention to the role of organic residue management in carbon sequestration and prevention of increasing global warming.
  • Authors:
    • Wuta, M.
    • Nyamangara, J.
    • Masaka, J.
  • Source: Archives of Agronomy and Soil Science
  • Volume: 60
  • Issue: 10
  • Year: 2014
  • Summary: Agricultural soils are a primary source of anthropogenic trace gas emissions, and the subtropics contribute greatly, particularly since 51% of world soils are in these climate zones. A field experiment was carried out in an ephemeral wetland in central Zimbabwe in order to determine the effect of cattle manure (1.36%N) and mineral N fertilizer (ammonium nitrate, 34.5%N) application on N2O fluxes from soil. Combined applications of 0kgN fertilizer+0Mg cattle manure ha(-1) (control), 100kgN fertilizer+15Mg manure ha(-1) and 200kgN fertilizer+30Mg manure ha(-1) constituted the three treatments arranged in a randomized complete block design with four replications. Tomato and rape crops were grown in rotation over a period of two seasons. Emissions of N2O were sampled using the static chamber technique. Increasing N fertilizer and manure application rates from low to high rates increased the N2O fluxes by 37-106%. When low and high rates were applied to the tomato and rape crops, 0.51%, 0.40%, and 0.93%, 0.64% of applied N was lost as N2O, respectively. This implies that rape production has a greater N2O emitting potential than the production of tomatoes in wetlands.
  • Authors:
    • Dalgaard, T.
    • Jorgensen, U.
    • Olesen, J. E.
    • Pugesgaard, S.
  • Source: Renewable Agriculture and Food Systems
  • Volume: 29
  • Issue: 1
  • Year: 2014
  • Summary: Anaerobic digestion of manure and crops provides the possibility of a combined production of renewable energy and organic fertilizer on organic farms and has been suggested as an option to improve sustainability of organic agriculture. In the present study, the consequences of implementation of anaerobic digestion and biogas production were analyzed on a 1000ha model farm with combined dairy and cash crop production, representing organic agriculture in Denmark. The effects on crop rotation, nitrogen flows and losses, yield, energy balance and greenhouse gas (GHG) emissions were evaluated for four scenarios of biogas production on the farm. Animal manure was digested for biogas production in all scenarios and was supplemented with: (1) 100ha grass-clover for biogas, (2) 100ha maize for biogas, (3) 200ha grass-clover for biogas and reduced number of livestock, and (4) 200ha grass-clover for biogas, reduced number of livestock and import of biomass from cuttings made in ungrazed meadows. These four scenarios were compared with the current situation in organic agriculture in Denmark and to a situation where slurry from conventional agriculture is no longer imported. Implementation of anaerobic digestion changed the nitrogen flows on the farm by increasing the slurry nitrogen plant availability and introducing new nitrogen sources from legume-based energy crops or meadows. The amount of nitrogen available for application as fertilizer on the farm increased when grass-clover was used for biogas production, but decreased when maize was used. Since part of the area was used for biogas production, the total output of foodstuffs from the farm was decreased. Effects on GHG emissions and net energy production were assessed by use of the whole-farm model FarmGHG. A positive farm energy balance was obtained for all biogas scenarios, showing that biomass production for biogas on 10% of the farm area results in an energy surplus, provided that the heat from the electricity production is utilized. The energy surplus implies a displacement of fossil fuels and thereby reduced CO2 emission from the farm. Emissions of N2O were not affected substantially by biogas production. Total emissions of methane (CH4) were slightly decreased due to a 17-48% decrease in emissions from the manure store. Net GHG emission was reduced by 35-85% compared with the current situation in organic agriculture. It was concluded that production of biogas on organic farms holds the possibility for the farms to achieve a positive energy balance, provide self-sufficiency with organic fertilizer nitrogen, and reduce GHG emissions.
  • 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:
    • Gavito, M. E.
    • Garciarreal, A.
    • Villamil-Echeverri, L.
    • Merlin-Uribe, Y.
    • Astier, M.
    • Masera, O. R.
  • Source: Ecological Indicators
  • Volume: 43
  • Issue: August
  • Year: 2014
  • Summary: There is a worldwide growing awareness of the negative impacts of the increasing fossil fuel reliance and greenhouse gas (GHG) emissions from agriculture, in particular for intensive crop systems. We analyze the energy balances and greenhouse gas emissions from export-oriented avocado orchards in Mexico. Avocado is a very important export crop and one of the main drivers of land-use change in the country. We compared 12 avocado orchards under organic and conventional management during two production cycles (2010 and 2011) in a representative region of Central Mexico. Our analysis shows no significant differences in energy consumption and GHG emissions between organic and conventional systems with 55 and 56 GJ ha(-1), and 3.30 t CO2 equiv. ha(-1) and 3.57 t CO2 equiv. ha(-1), respectively. Organic systems show three times more use of renewable energy than their conventional counterparts. However both systems depend heavily on fossil fuel inputs, machinery and N-fertilizers (synthetic or organic). Also, there is a high heterogeneity in management practices and input application within both systems, which is reflected in a large variation of their energy-related parameters. Given that avocado production is rapidly expanding in Mexico, a move toward organic production without systematically changing toward less fossil fuel dependent agricultural practices would not be sufficient to ensure a sustainable production. (c) 2014 Elsevier Ltd. All rights reserved.