85 research outputs found

    Selection of the Most Appropriate Tillage System Based on TOPSIS Model with Emphasize on Impact of Different Tillage Systems on Yield

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    Among the various agricultural operations, tillage alone accounts for 60% of the energy consumed in agriculture. Other concerns, such as soil compaction, time management, economic issues, porosity reduction, moisture storage capacity, as well as a 25% increase in water and wind erosion, has further fueled efforts to improve tillage methods. In this regard, conservation tillage is more considered by experts. This study was conducted to evaluate important indices of wheat production in different tillage methods. Two plots located in Moghan Agro Co. were selected and were divided into four equal 2.8 hectares. Experiments were performed in randomized complete block design (RCBD) with four tillage systems including conventional, tillage1, tillage2 and direct tillage in which two common wheat cultivars were planted. The results implied that the effect of all four tillage methods was significant at the probability level of 0.001 and the indices such as fuel consumption, efficiency, the number of traffic on farm, land preparation time and its cost per hectare, crop yield, plant density and tiller number were improved using the no-tillage and low tillage2 methods. The results were also re-evaluated using TOPSIS method and the tillage system with CL of 0.98 was selected as the best method. Therefore, direct cultivation can be an appropriate alternative to conventional tillage in sustainable wheat productio

    Technology Promotion and Scaling in Support of Commodity Value Chain Development in Africa

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    Strengthening the production and processing of key food commodities forms the basis of agricultural development in Africa. These value chains follow a quasi-linear progression across seven main segments: farm planning > land preparation and crop establishment > field production > harvest > post-harvest handling > marketing > and value addition. Each of these consists of sub-segments whose improvement depends upon promotion and adoption of specific modernizing technologies. The technologies either have commercial application, as with the distribution of production input products and labor-saving equipment, or are related to management of farms and processing. For crop commodities, these products include improved varieties planted with more and better-formulated fertilizers and pest management materials. Management options are primarily directed toward the better conservation of resources and wiser integration of different farm enterprises. Key factors underlying value chain advancement include wider application of digital services, more effective incentives for climate-smart action, increased mechanization and irrigation, improved marketing efficiency and fairness, and incentives for value-creating agro-processing. An analogous set of factors also relate to value chains supporting animal enterprise. Attracting women and youth to meaningful careers in agriculture is particularly important since they are major stakeholders in the scaling of much-needed technologies and business models

    Biofuels, greenhouse gases and climate change. A review

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    International audienceBiofuels are fuels produced from biomass, mostly in liquid form, within a time frame sufficiently short to consider that their feedstock (biomass) can be renewed, contrarily to fossil fuels. This paper reviews the current and future biofuel technologies, and their development impacts (including on the climate) within given policy and economic frameworks. Current technologies make it possible to provide first generation biodiesel, ethanol or biogas to the transport sector to be blended with fossil fuels. Still under-development 2nd generation biofuels from lignocellulose should be available on the market by 2020. Research is active on the improvement of their conversion efficiency. A ten-fold increase compared with current cost-effective capacities would make them highly competitive. Within bioenergy policies, emphasis has been put on biofuels for transportation as this sector is fast-growing and represents a major source of anthropogenic greenhouse gas emissions. Compared with fossil fuels, biofuel combustion can emit less greenhouse gases throughout their life cycle, considering that part of the emitted CO2 returns to the atmosphere where it was fixed from by photosynthesis in the first place. Life cycle assessment (LCA) is commonly used to assess the potential environmental impacts of biofuel chains, notably the impact on global warming. This tool, whose holistic nature is fundamental to avoid pollution trade-offs, is a standardised methodology that should make comparisons between biofuel and fossil fuel chains objective and thorough. However, it is a complex and time-consuming process, which requires lots of data, and whose methodology is still lacking harmonisation. Hence the life-cycle performances of biofuel chains vary widely in the literature. Furthermore, LCA is a site- and timeindependent tool that cannot take into account the spatial and temporal dimensions of emissions, and can hardly serve as a decision-making tool either at local or regional levels. Focusing on greenhouse gases, emission factors used in LCAs give a rough estimate of the potential average emissions on a national level. However, they do not take into account the types of crop, soil or management practices, for instance. Modelling the impact of local factors on the determinism of greenhouse gas emissions can provide better estimates for LCA on the local level, which would be the relevant scale and degree of reliability for decision-making purposes. Nevertheless, a deeper understanding of the processes involved, most notably N2O emissions, is still needed to definitely improve the accuracy of LCA. Perennial crops are a promising option for biofuels, due to their rapid and efficient use of nitrogen, and their limited farming operations. However, the main overall limiting factor to biofuel development will ultimately be land availability. Given the available land areas, population growth rate and consumption behaviours, it would be possible to reach by 2030 a global 10% biofuel share in the transport sector, contributing to lower global greenhouse gas emissions by up to 1 GtCO2 eq.year−1 (IEA, 2006), provided that harmonised policies ensure that sustainability criteria for the production systems are respected worldwide. Furthermore, policies should also be more integrative across sectors, so that changes in energy efficiency, the automotive sector and global consumption patterns converge towards drastic reduction of the pressure on resources. Indeed, neither biofuels nor other energy source or carriers are likely to mitigate the impacts of anthropogenic pressure on resources in a range that would compensate for this pressure growth. Hence, the first step is to reduce this pressure by starting from the variable that drives it up, i.e. anthropic consumptions
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