Soil Quality In Organic Crop Production Systems

Cory Roberts, University of Guelph, Guelph, ON

Stewardship of the soil is a key principle of organic management. Does organic management lead to a difference in soil quality? This study measured soil quality indicators on 9 organic and 9 conventional farms in southern Ontario. All organic farms had been organic for at least 10 years, allowing time for organic soil processes to establish. Farms were matched as neighbours with similar soil topography and type. Soils were sampled in fall of 2002 and again in summer of 2003.

Organic carbon levels were similar on matched farms, while percent nitrogen was higher on organic farms. Soil respiration was greater on some organic farms than on their neighbours, though taken overall the difference was small. Soil microbial biomass was higher on organic farms than on the corresponding conventional farms.

The data from this study suggests that soils managed organically differ in soil quality from those managed conventionally. The sample size was relatively small; farm to farm variability reduced the strength of the conclusions that could be drawn. Further research will be required to verify these conclusions and to understand the causes of these differences. In particular, long-term field studies are needed to control the variability in management.


Source
1st Canadian Organic Agriculture Research Workshop, University of Guelph, January 2004


Contact Info:
Cory Roberts, Department of Land Resource Science, University of Guelph, Guelph, Ontario N1G 2W1 CANADA
email: robertsc@uoguelph.ca


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