Long-term effects of organic and conventional farming on soil erosion
John P. Reganold*, Lloyd F. Elliott† & Yvonne L. Unger‡
*Department of Agronomy and Soils, Washington State University, Pullman, Washington 99164, USA
†Agricultural Research Service, US Department of Agriculture, Pullman, Washington 99164, USA
‡Department of Plant and Soil Sciences, University of Maine, Orono, Maine 04469, USA
Conventional, intensive tillage farming systems have greatly increased crop production and labour efficiency. But, serious questions are being raised about the energy-intensive nature of these systems and their adverse effects on soil productivity and environmental quality1,2. This concern has led to an increasing interest in organic farming systems because they may reduce some of the negative effects of conventional agriculture on the environment3,4. We compare the long-term effects (since 1948) of organic and conventional farming on selected properties of the same soil. The organically-farmed soil had significantly higher organic matter content, thicker topsoil depth, higher polysaccharide content, lower modulus of rupture and less soil erosion than the conventionally-farmed soil. This study indicates that, in the long term, the organic farming system was more effective than the conventional farming system in reducing soil erosion and, therefore, in maintaining soil productivity.
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