Đang chuẩn bị liên kết để tải về tài liệu:
Biofuels, Solar and Wind as Renewable Energy Systems_Benefits and Risks Episode 2 Part 9

Tham khảo tài liệu 'biofuels, solar and wind as renewable energy systems_benefits and risks episode 2 part 9', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 17 Organic and Sustainable Agriculture and Energy Conservation 441 climatic variability providing soil and crop characteristics that can better buffer environmental extremes especially in developing countries. However it has to be pointed out that local specificity plays an important role in determining the performance of a farming system what is sustainable for one region may not be for another region or area Smolik et al. 1995 . So more work has to be done to acquire knowledge about the comparative sustainability of other farming systems. 17.2.1.2 Organic Farming for Developing Countries Energy and economic savings from organic farming can offer an important opportunity for developing countries to produce crops with limited costs and environmental impact. Some authors claim that organic farming can reduce food shortage by increasing agricultural sustainability in developing countries contributing quite substantially to the global food supply while reducing the detrimental environmental impacts of conventional agriculture Netuzhilin et al. 1999 Paoletti et al. 1999 Pretty and Hine 2001 FaO 2002 Pretty et al. 2003 Badgley et al. 2007 . Pretty and Hine 2001 surveyed 208 projects in developing tropical countries in which contemporary organic practices were introduced they found that average yield increased by 5-10 in irrigated crops and 50-100 in rainfed crops. However those claims have been challenged by different authors e.g. McDonald et al. 2005 Cassman 2007 Hudson Institute 2007 Hendrix 2007 who dispute the correctness of both the accounting and comparative methods employed. Hudson Institute 2007 refers that in most of the farming cases accounted as organic by Pretty and Hine 2001 chemical fertilisers and or pesticides have been regularly applied. The latter may be a sound observation. However we argue that the amount of inputs employed plays a critical role in maintaining the long term sustainability of farming systems. So although the organic certification .