我国生态农业发展模式初探

生态农业是我国农业未来发展的根本方向,而我国农业地域的自然经济条件的差异决定了在不同地域要培育多样的生态农业发展模式。现阶段,我国要着力推进和培育城镇近郊多功能都市生态农业发展模式,农产品主产区规模化生态农业发展模式,生产条件较差农业区综合效益优化生态农业发展模式三大生态农业模式。     

Biofuels and ecoagriculture: can bioenergy production enhance landscape-scale ecosystem conservation and rural livelihoods?

Global development of the biofuel sector is proceeding rapidly, driven by national policy mandates, government subsidies, and profit opportunities for farmers, agribusiness and energy companies. To date, most investment in—and dialogue on—biofuels has focused on large-scale production of liquid transport fuels. A smaller set of efforts has explored the potential of biofuels to promote rural development by reducing energy poverty among the world's two billion poorest people. Here, we consider the potential of these diverse approaches to promote the goals of ecoagriculture: namely, sustainable agricultural production (including biofuel feedstocks), conservation of biodiversity and ecosystem services and viable rural livelihoods. Using a landscape planning framework, we review empirical evidence and identify criteria for designing biofuel production systems that promote this trio of goals. Biofuel development has the greatest potential when biomass production is an ‘interstitial’ activity and when processing and use occurs at the local level. Larger scale production for regional or global liquid fuel markets may be beneficial under some circumstances, but a stronger policy framework is needed to guide this approach. To advance biofuels for sustainable development, while avoiding serious risks, investment must shift to include a variety of ecoagriculture-compatible pathways. Supportive public policies and market incentives must be developed before the biofuel sector develops strong path-dependence toward unsustainable outcomes.     

Impacts of socio-economic policies on agriculture in the mountainous upland of the Dalinghe river watershed,Northeast China

Ghana, as the second largest global producer of cocoa, is strategically positioned on the world market. Consumer concerns over ethical and environmental issues associated with cocoa production are a potential threat to its position. These concerns have given rise to certification. Certification dictates the way cocoa can be produced and consequently affects producers’ incomes and environmental services. The expected profitability, yield, and environmental impact of Rainforest Alliance certified shade-grown cocoa production (RA-Cocoa) is estimated and compared to an extensive shaded production system (Ext-Cocoa) and an intensified full sun production system (High-Tech). Ext-Cocoa represents most cocoa production systems in Ghana, while High-Tech is promoted by the government as a tool for attaining its target output of 1 million tons. Under the baseline assumptions High-Tech was the most profitable; RA-Cocoa generated positive returns, while Ext-cocoa was a break even proposition. Simulation of different policy scenarios did not affect the rank order of the baseline outcome. The Ext-Cocoa yield was 28% of the RA-Cocoa yield, which was 78% of the High-Tech yield. The environmental services maintained at the plot level of RA-Cocoa production system are greater than those of the High-Tech production system. However, the 228,000 ha of additional forest land required to produce 1 million tons with RA-Cocoa questions which system would impact environmental services the least.