CROP-ROTATION AND TILLAGE EFFECTS ON SOIL ORGANIC-CARBON AND NITROGEN

Sustaining or increasing soil productivity depends in part on soil and crop management practices that maintain or increase soil organic matter. This study was conducted to determine the effects of tillage, crop rotation, and fertilizer N on soil organic C and N. Two long-term tillage/rotation studies and one long-term rotation/N-rate study were conducted on eastern Kansas soils. Soils were sampled from conventional (CT) and no-tillage (NT) treatments. Crop management systems that include rotations with high residue-producing crops and maintenance of surface residue cover with reduced tillage result in greater soil organic C and N, which may improve soil productivity.