CATTLE GRAZING INFLUENCES ON PERCENTAGE CORN RESIDUE COVER

Crop residue left on the soil surface after planting is a primary comp onent of the the majority of conservation plans developed to comply wi th the conservation provisions of the 1985 Food Security Act. During i mplementation of these plans, Extension clientele began to ask what in fluences cattle grazing had on residue cover. To help answer some of t hese questions, we measured percentage corn (Zea mays L.) residue cove r remaining on the soil surface after grazing and after no-till planti ng during three planting seasons. Compared to non-grazed, undisturbed conditions, the amount of cover were reduced by an average of 26% (P < 0.001) by grazing and by 37% (P < 0.001) when the residue was disturb ed by the combination of grazing and planting. A simple grazing reduct ion factor of 0.43%.ha.day(-1).1000 kg animal unit(-1) approximately 0 .5%.acre.day(-1).1000 lb animal unit(-1)) is proposed to estimate corn residue cover reduction due to grazing when site-specific values of p ercent residue cover are not available.