ABSTRACT:
Disk-disk-mulch harrowing, strip-rotary, and tri-level bed shaper till-plant systems were evaluated for their effectiveness in reducing runoff in continuous corn under high- and low-pressure, center-pivot sprinkler irrigation. The center-pivot system was modified to apply water at 55 psi at 0.5 inch/hour and at 20 psi at 1.5 inches/hour on alternate quarters of the circle. The low-pressure irrigation increased irrigation runoff 30% from combined till-plant systems. The strip-rotary till-plant system controlled runoff best, with 12% of the growing-season rainfall and less than 4% of the irrigation water lost as runoff. The effect of water pressure on stored soil water and yields was significant when runoff exceeded 5% of the applied water by sprinkler irrigation. Corn grain yields were not influenced by the effectiveness of till-plant systems to control runoff, but rather by their effectiveness in controlling volunteer corn. Corn grain yields declined 1.3 bushels/acre for every 100 pounds/acre of volunteer corn dry matter produced. Runoff and soil erosion as well as volunteer corn were controlled best by the least amount of tillage and surface-layer incorporation of harvest losses before planting.
Footnotes
Rome H. Mickelson is an agricultural engineer at the U.S. Central Great Plains Research Station, Agricultural Research Service, U.S. Department of Agriculture, Akron, Colorado 80720. E. E. Schweizer is a plant physiologist at the Crops Research Laboratory, Colorado State University, Fort Collins, 80523. Trade or company names are included for the benefit of the reader and do not imply endorsement or preferential treatment of the product by USDA. This article is a contribution from ARS-USDA.
- Copyright 1987 by the Soil and Water Conservation Society
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