Can organic agriculture elaborate a scientifically based, resource-efficien and agroecological approach to low-input farm management? This review examines the literature from temperate regions, with a particular emphasison Canadian and USstudies that relate to environmental and ecological impacts of organic agriculture with respect to (i )soil organic matter storage, (ii) soil quality/soil health, (iii) nutrient loading and risks of off-farm nutrient and agrochemical losses, (iv) biodiversity and (v) energy use and global warming potential. The context and implications of semi-arid conditions and low soil P levels, common to many organic farms in North America, and wide spread adoption of genetically engineered crops in conventional production, is also... |