Environmental impacts of organic agriculture: A Canadian perspective

Abstract

Canada, in 2009, will enact a regulatory regime to oversee certified organic agricultural productions systems, based on a management standard. The overreaching goal of that standard is to develop farm enterprises that are “sustainable and harmonious with the environment”. However, empirical evidence to shed light on claims of environmental benefits from organic agriculture is particularly scarce in Canada and North America generally, and has not been comprehensively summarized. This review examines the literature of Canadian and US studies which relate to environmental impacts of organic agriculture within the selected indicators of: (i) soil organic matter storage and soil quality/soil health; (ii) plant and wildlife biodiversity; (iii) energy use; (iv) nutrient loading and off-farm nutrient losses; and (v) climate change and greenhouse gas emissions. The empirical evidence presented suggests organic farming system attributes regarding cropping, floral, and habitat diversity, nutrient intensity, soil management, energy and pesticide use, etc., are sufficiently distinct as to impart potentially important environmental benefits across the indicator categories examined. However, on average, crop yields under organic management regimes continue to lag behind those obtained by conventional management systems. More research is needed to validate these results, for the benefit of producers, consumers and policy makers as they decide the relative importance and contribution of organic farming systems to the Canadian food marketplace and agrifood sector. Key words: Organic agriculture, farming system, soil, biodiversity, energy, greenhouse gases