This report estimates that CI leads to a small increase of 67,000 hectares in summerfallow in Manitoba and Saskatchewan, but a decrease of 63,000 in Alberta. The net impact of these conflicting influences could not be estimated without a multi-product, regional model. The net effect of CI is to increase summerfallow slightly in Manitoba and Saskatchewan, and decrease it in Alberta. In summary, CI has a very small net effect on summerfallow acreage with the direction of change dependent on a number of factors. This effect could reduce organic matter in the soil and increase the opportunity for soil erosion, reducing soil quality, increase risk of water contamination due to heavy use of pesticides and increasing silt in surface water.
Marginal land tends to be more prone to erosion, and sometimes provides habitat for wildlife.
While this land is economically marginal, it is not known how much is environmentally marginal as well. While the 1994 report found little or no environmental impact directly attributable to CI, it nonetheless made several recommendations based on particular problems or opportunities. This provides an opportunity to establish minimum acceptable guidelines for CI at a national level. The definitions of good farming practices within CI are the responsibility of provincial CI officials who develop and administer CI programs across Canada. These definitions are continually adapted, particularly in view of producer and public interest in sustaining agricultural production and decreasing off-farm impacts.