The Effects of Mulch Tillage on Runoff, Erosion, Soil Properties, and Crop Yields

Abstract The effects of mulch and clean tillage methods on runoff, erosion, soil properties and crop yields were studied over a period of 10 years. Corn was grown each summer following winter cover crops of vetch and rye mixed and crimson clover. Mulch tilled land was prepared for planting corn by disk‐harrowing, and by disk‐harrowing plus loosening the soil with a spring‐tooth tiller. A disk or moldboard plow was used to prepare the turn‐plowed treatments. Runoff and erosion were reduced considerably under mulch tillage. The degree of aggregation of the mulch tilled soil increased more rapidly than that of the turn‐plowed soil. The vetch and rye cover crop caused greater improvement in degree of aggregation than the crimson clover. Soil aggregation of the clean tilled crimson clover treatment decreased during the test. Soil aggregation of the clean tilled soil without a cover crop decreased significantly. Organic matter content of the vetch and rye mulch‐tilled soil increased significantly. The organic matter content of the vetch and rye mulch tilled soil was significantly greater than that of either the vetch and rye clean tilled or the clean‐tilled without a cover crop. The organic matter content of the clean‐tilled soil without a cover crop did not change materially. The total nitrogen contents of all the soils with cover crop treatments, except the clean tilled crimson clover, increased significantly during the test. The nitrogen contents of the mulch‐tilled soils were significantly greater than those which were clean‐tilled with cover crop treatments. There was no appreciable change in the total nitrogen content of the clean tilled soil without a cover crop. The differences between corn yields of all treatments for all years, except 1950, were not significant. The average corn yields of all treatments were approximately equal.