BIOLOGICAL AND BIOCHEMICAL SOIL PROPERTIES IN NO-TILL CORN WITH DIFFERENT COVER CROPS

Cover cropping impacts soil properties in many positive ways. These in clude higher total carbon, which usually contributes to increased cati on exchange capacity and water-holding capacity. Enhanced soil physica l and chemical properties result in a better environment for the activ ity of soil microorganisms. We conducted a study of biological propert ies in no-till corn plots receiving either 0 or 168 kg N ha(-1). Plots were planted in the fall each year with a hairy vetch (Vicia villosa Roth), winter wheat (Triticum aestivum L.), or not cover crop. The vet ch cover resulted in the highest organic C accumulations, and the addi tion of N to the wheat or no cover plots increased C relative to the n o N treatments. Soil organic C was not different between the vetch wit h adn without N, but pH was significantly reduced by N fertilization. Hairy vetch had a greater effect on microbial numbers than did the whe at cover or no cover. The greatest bacterial numbers were observed in the vetch with no N treatment. Acid phosphatase, arylsulfatase, beta-g lucosidase and L-asparaginase activities were all higher in the vetch with no N treatment than any of the other combinations. In the wheat a nd no cover treatments, the enzyme activities mentioned earlier were a ll higher in the 168 kg N treatments. Soil treatments that increased s oil organic C enhanced the activity of soil microorganisms and/or prov ided a better environment for the stabilization of microbially produce d soil enzymes. Our data indicated that the use of cover crops signifi cantly enhanced soil biological properties as measured by microbial nu mbers and enzyme activities. The use of cover crops provides soil qual ity benefits in addition to the reduction in soil loss attained with t hese systems.