19862015
  • Authors:
    • de Cortazar-Atauri,I. G.
    • Huard, F.
    • Bourgeois, G.
    • Caubel, J.
    • Launay, M.
    • Bancal, M. O.
    • Brisson, N.
  • Source: AGRICULTURE ECOSYSTEMS & ENVIRONMENT
  • Volume: 197
  • Year: 2014
  • Summary: Since weather has a major influence on the occurrence and development of crop diseases, valuable insight toward future agricultural planning emerges with assessment tools to evaluate fungal disease pressure and crop regional suitability under projected future climatic conditions. The aim of this study was to develop two climatic indicators, the average infection efficiency (AIE) and the number of infection days (NID), to quantify the potential effects of weather on the intensity and occurrence of pathogen infection. First, a simple and continuous infection function accounting for daily temperature and leaf wetness duration variations was implemented. The function was then parameterized from published data sets for five major contrasting fungal diseases affecting crops in Northern France: phoma of oilseed rape, late blight of potato, downy mildew of grape, leaf rust of wheat and net blotch of barley. Finally, AIE and NID were calculated for the recent past (1970-2000) and the future A1B climate scenario (2070-2100). An overall decrease in the risk of infection was shown for potato late blight and downy mildew of grapevine for all months during the period when the host plant is susceptible to infection. There were greater differences for the other three diseases, depending on the balance between warmer temperatures and lower humidity. The future climate would result in a later onset of disease and higher infection pressure in late autumn. In spring, for brown rust of wheat and net blotch of barley, the climatic risk for infection is expected to occur earlier but would result in lower infection pressure in May. These findings highlighted the need to use an infra-annual (monthly or seasonally) scale to achieve a relevant analysis of the impact of climate change on the infection risk. The described indicators can easily be adapted to other pathogens and may be useful for agricultural planning at the regional scale and in the medium term, when decision support tools are required to anticipate future trends and the associated risks of crop diseases.
  • Authors:
    • Archer, D. W.
    • Lee, J.
  • Source: Scopus
  • Volume: 1
  • Year: 2014
  • Summary: An important driver for the adoption of renewable fuels is reduction in greenhouse gas (GHG) emissions, and the quantity of greenhouse gas reductions achieved is used in determining the fuel feedstocks and conversion pathways that can be used for fuels to meet the U.S. renewable fuels standard. Estimating GHG emissions from cropping system is an important component in quantifying GHG emissions through entire process from feed stock to final product use for oilseed based renewable fuels. Soil Organic Carbon (SOC) change is a key measure for calculating GHG emission from cropping systems because increase of SOC is regarded as C02 deposition from atmosphere to soil. Even though many researchers have simulated long term impacts of cropping system on SOC, the calibration and validation for C dynamic parameters using long-term soil profile data have been limited. The objective of this study is modeling long-term SOC change under impact of Brassica oil seed cropping systems with calibration and validation of soil C dynamics parameters in the EPIC model. We validated crop growth parameters from several areas of Northern Great Plains regions using field scale crop yield and management data at Mandan, ND. Soil C dynamics parameters (microbial decay rate coefficient) were calibrated and validated using soil profile data in 1983, 1991 and 2001 from long-term soil quality studies conducted at Mandan, ND since 1983. After calibration and validation, SOC and crop yields were modeled for each SSURGO soil map unit in Ward County, ND, one of pilot counties being evaluated for potential oilseed supply for hydrotreated renewable jet fuel production. The simulation was conducted under two rotation scenarios, canola-spring wheat-spring wheat and continuous spring wheat with no-tillage. The soil parameters from SSURGO were initialized by 100 year run with continuous spring wheat before imposing the two rotation scenario treatments. The results from 50-year simulation indicate that the canola cropping system is beneficial to store SOC compared to continuous spring wheat in all test map units. However, differences vary across soil map units.
  • Authors:
    • Tambong, J.
    • Voroney, P.
    • Ondoua, B.
    • Nkoa, R.
  • Source: Sustainable Agriculture Research
  • Volume: 3
  • Issue: 4
  • Year: 2014
  • Summary: Knowledge on the interaction between plants and organic amendments is critical for the basic understanding of agroecosystems sustainability. Organic amendments are of great interest in agriculture by virtue of their ability to restore lost soil organic carbon in eroded or conventionally cultivated soils. The major objective of this study was to demonstrate and model the differential response of crop species to organic amendments. Despite the potential of such an interaction to improve crop production, it has never been formally demonstrated in a planned experiment. A two-year greenhouse experiment set as 3*3*5 factorial in a strip-split plot design was conducted. The effects of crop species, type of organic amendment, and application rates on grain yield of soybean, canola, and wheat were evaluated. To account for the asymmetry of the concave responses of soybean, mathematical transcendental models were fitted, for the first time, to yield data. The interaction between crop species and amended soils was highly significant. Soybean displayed concave transcendental yield responses whereas canola and wheat exhibited negative exponential responses, irrespective of the type of amendment. Turkey compost outperformed turkey litter and beef manure by 30% and 52%, respectively, with respect to soybean production; whereas turkey litter outperformed turkey compost and beef manure by 144% and 264%, respectively, with respect to canola and wheat production. It is concluded that in greenhouse settings and perhaps field conditions, growth and development of crop species can be enhanced by matching the specific characteristics of organic amendments to the specific nutrients demand of crop species.
  • Authors:
    • Nyamangara, J.
    • Wuta, M.
    • Nyamadzawo, G.
    • Smith, J. L.
    • Rees, R. M.
  • Source: NUTRIENT CYCLING IN AGROECOSYSTEMS
  • Volume: 100
  • Issue: 2
  • Year: 2014
  • Summary: In many smallholder farming areas southern Africa, the cultivation of seasonal wetlands (dambos) represent an important adaptation to climate change. Frequent droughts and poor performance of rain-fed crops in upland fields have resulted in mounting pressure to cultivate dambos where both organic and inorganic amendments are used to sustain crop yields. Dambo cultivation potentially increases greenhouse gas (GHG) emissions. The objective of the study was to quantify the effects of applying different rates of inorganic nitrogen (N) fertilisers (60, 120, 240 kg N ha -1) as NH 4NO 3, organic manures (5,000, 10,000 and 15,000 kg ha -1) and a combination of both sources (integrated management) on GHG emissions in cultivated dambos planted to rape ( Brassica napus). Nitrous oxide (N 2O) emissions in plots with organic manures ranged from 218 to 894 g m -2 h -1, while for inorganic N and integrated nutrient management, emissions ranged from 555 to 5,186 g m -2 h -1 and 356-2,702 g m -2 h -1 respectively. Cropped and fertilised dambos were weak sources of methane (CH4), with emissions ranging from -0.02 to 0.9 mg m -2 h -1, while manures and integrated management increased carbon dioxide (CO 2) emissions. However, crop yields were better under integrated nutrient management. The use of inorganic fertilisers resulted in higher N 2O emission per kg yield obtained (6-14 g N 2O kg -1 yield), compared to 0.7-4.5 g N 2O kg -1 yield and 1.6-4.6 g N 2O kg -1 yield for organic manures and integrated nutrient management respectively. This suggests that the use of organic and integrated nutrient management has the potential to increase yield and reduce yield scaled N 2O emissions.
  • 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:
    • Aoun,W. B.
    • El-Akkari,M.
    • Gabrielle,B.
    • Flenet,F.
  • Source: Proceedings of the 9th International Conference on Life Cycle Assessment in the Agri-Food Sector
  • Year: 2014
  • Summary: Nitrogen fertilization practices have a significant effect on the LCA results of biodiesel chains, which warrants reliable inventory data. In this study focused on the Lorraine region (eastern France), we established a typology of oilseed rape fields based on fertilization practices, and used the agro-ecosystem model CERES-EGC in lieu of generic emission factors to simulate the productivity and externalities associated with oilseed farming. The results were subsequently used to generate an LCA of biodiesel from oilseed rape. We also tested the effect of improved practices on the LCA results. In Lorraine, oilseed rape crops appeared to be frequently over fertilized compared to best management practices. Switching to improved practices with optimal fertilization has a potential to reduce the GWP of 1 megajoule of biodiesel by around 6 gr CO 2eq, against a total life-cycle of 43.9 gr CO 2eq.
  • 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:
    • Jarosz, Z.
    • Faber, A.
    • Borzecka-Walker, M.
    • Syp, A.
    • Pudelko, R.
  • Source: Journal: Food, Agriculture and Environment (JFAE)
  • Volume: 11
  • Issue: 1
  • Year: 2013
  • Summary: The production of bio diesel from rape seed, in accordance with Directive 2009/28/EC (RED), requires estimation on greenhouse gas (GHG) emissions in the life cycle of bio fuels and reduction size in comparison to diesel as fossil fuel. The study sought a reduction in GHG emissions from agriculture, in the full life cycle of Fatty Acid Methyl Esters (FAME) by optimisation of nitrogen fertilisation of rape seed, the selection of fertilisers with lower emissions arising from their production and increased organic carbon sequestration in the soil by the use of reduced or no tillage (direct sowing). It was found that an optimisation of the nitrogen (N) dose and manipulations of fertiliser N type does not guarantee a 50% reduction in GHG emissions. The reduction of GHG emissions under reduced tillage, which increases the organic carbon sequestration in the soil, is achievable only at a dose of 150 kg N ha(-1) in the form of a urea ammonium nitrate (UAN) solution or mixture of ammonium nitrate + ammonium sulphate. The increase of organic carbon sequestration in the soil through the conversion of conventional oilseed rape cultivation to a no tillage system increases the reduction of GHG emissions by 58-63% at a dose of 150 kg N ha(-1) and 54-59% at a dose of 180 kg N ha(-1).
  • Authors:
    • Borgesen, C. D.
    • Kristensen, I. T.
    • Hermansen, J. E.
    • Olesen, J. E.
    • Elsgaard, L.
  • Source: Acta Agriculturae Scandinavica, Section B — Soil & Plant Science
  • Volume: 63
  • Issue: 3
  • Year: 2013
  • Summary: Biofuels from bioenergy crops may substitute a significant part of fossil fuels in the transport sector where, e.g., the European Union has set a target of using 10% renewable energy by 2020. Savings of greenhouse gas emissions by biofuels vary according to cropping systems and are influenced by such regional factors as soil conditions, climate and input of agrochemicals. Here we analysed at a regional scale the greenhouse gas (GHG) emissions associated with cultivation of winter wheat for bioethanol and winter rapeseed for rapeseed methyl ester (RME) under Danish conditions. Emitted CO2 equivalents (CO2eq) were quantified from the footprints of CO2, CH4 and N2O associated with cultivation and the emissions were allocated between biofuel energy and co-products. Greenhouse gas emission at the national level (Denmark) was estimated to 22.1 g CO2eq MJ(1) ethanol for winter wheat and 26.0 g CO2eq MJ(1) RME for winter rapeseed. Results at the regional level (level 2 according to the Nomenclature of Territorial Units for Statistics [NUTS]) ranged from 20.0 to 23.9 g CO2eq MJ(1) ethanol and from 23.5 to 27.6 g CO2eq MJ(1) RME. Thus, at the regional level emission results varied by up to 20%. Differences in area-based emissions were only 4% reflecting the importance of regional variation in yields for the emission result. Fertilizer nitrogen production and direct emissions of soil N2O were major contributors to the final emission result and sensitivity analyses showed that the emission result depended to a large extent on the uncertainty ranges assumed for soil N2O emissions. Improvement of greenhouse gas balances could be pursued, e.g., by growing dedicated varieties for energy purposes. However, in a wider perspective, land-use change of native ecosystems to bioenergy cropping systems could compromise the CO2 savings of bioenergy production and challenge the targets set for biofuel production.
  • Authors:
    • Emmerling, C.
    • Fries, J.
    • Froeba, N.
    • Felten, D.
  • Source: Renewable Energy
  • Volume: 55
  • Year: 2013
  • Summary: Biomass for bioenergy is an important option within global change mitigation policies. The present research focused on energy net production, net reduction of greenhouse gases (GHG) (considered as CO2-equivalents), and energy output:input ratio of the energy cropping systems 'rapeseed', 'maize', and 'Miscanthus'. The system-specific main products were biodiesel (rapeseed), electricity from biogas (maize), and Miscanthus chips (loose, chopped material); the related substituted fossil resources were diesel fuel (rapeseed), electricity from the German energy mix (maize), and heating oil (Miscanthus). However, research did not aim for a direct quantitative comparison of the crops. The study followed a case study approach with averaged data from commercial farms within an enclosed agricultural area (<5 km(2)) in Western Germany. Cultivation techniques were considered as communicated by farmers and operation managers; the diesel fuel consumption of agricultural machinery was modeled using an online-based calculator of the German Association for Technology and Structures in Agriculture (KTBL). Overall, rounded net energy production amounted to 66 GJ ha(-1) (rapeseed), 91 GJ ha(-1) (maize), and 254 GJ ha(-1) yr(-1) (Miscanthus); the related energy output:input ratios were 4.7 (rapeseed), 5.5 (maize), and 47.3 (Miscanthus), respectively. Compared to the respective fossil fuel-related energy supply, CO2-equivalent reduction potential ranged between 30 and 76% for electrical energy from maize biomass, 29 -82% for biodiesel from rapeseed, and 96-117% for Miscanthus chips, depending on whether or not the accruing by-products rapeseed cake, glycerin (rapeseed cropping system), and waste heat (maize) were considered. True 'CO2-neutrality' was only reached by the Miscanthus cropping system and was related to an additional credit from carbon sequestration in soil during the cultivation period; thus, this cropping system could be attributed to be a CO2-sink. The study indicated that bioenergy can be produced sustainably under commercial farming conditions in terms of a significantly reduced consumption of natural resources.