Crop Residue Cover and Manure Incorporation â•fl Part I: Reduction of Cover

Averaged across crop, year and season , residue cover reduction was significantly less for coulter-type applicators than for disk-type applica-tors (P<0.001), disk-type applicators reduced residue cover significantly less than chisel and sweep injectors (P<0.001), and chisel and sweep injec-tors reduced residue cover similar to a tandem disk (P=0.398). Ranges of values to estimate the percentage of the initial amount of corn (non-fragile) residue cover that will remain following the use of manure application/ incorporation components are: chisel and sweep injectors, 30 to 65 percent; disk-type applicators, 40 to 65 percent ; and coulter-type applicators, 80 to 95 percent. Similarly, for soybean or oat (fragile) residue, estimates of the initial residue cover remaining are: chisel and sweep injectors, 5 to 15 percent; disk-type applicators, 15 to 40 percent; and coulter-type applica-tors, 65 to 80 percent. These values can be used for estimation or planning purposes when site-specific data are not available. Results of this research indicate that certain configurations of manure application/incorporation equipment may leave adequate residue cover for acceptable soil erosion control , particularly in non-fragile residue. However, the equipment must be selected, adjusted and operated with the dual objectives of residue and manure management, rather than used simply as a means of manure disposal.