Research Progress Report 368
February 1970
An Evaluation of Tillage-Planting Systems for Corn Production
D.	R. Griffith, S. D. Parsons, J. V. Mannering, H. M. Galloway, M. A. Ross, P. R. Robbins and R. T. Huber
Departments of 
Agronomy, Agricultural Engineering, Botany and Plant Pathology, Agricultural Economics, and Entomology
SUMMARY
Five no-plow tillage planting systems, four systems using the moldboard plow and two systems which involve plowing every fourth year, were compared on five soil types in Indiana in 1967 and 1968.
Stand and weed control have been the dominant factors influencing yield of the no-plow systems in both years. Grass control from preemergence herbicides has not been satisfactory in the chisel,. strip rotary and no-til coulter systems. Stands in chisel and no-til planting have been reduced, compared to conventional tillage when planting in moist, compacted soil.
Best stands were achieved with the ridged till plant system. All problems with the no-plow systems were more evident on fine textured soi Is.
Corn under all no-plow systems tended to grow and mature more slowly than corn in conventionally tilled plots. A special comparison at the northern location in 1968 showed that no-til corn planted under residues grew more slowly, had more barren stalks, and yielded ten bushels per acre less than no-til corn planted in bare soil. This was in a season that was cooler and wetter than normal.
Preliminary insect sampling among tillage plots in the sod planting experiment showed that systems leaving most of the residues near the soil surface had higher infestations of corn borer than did systems where residues were plowed under.
A water management study comparing three no-plow systems with conventional tillage on nine per cent slope showed that all no-plow systems in the study cut soi I loss by 75 per cent or more.
A ridged system going across slope was most effective in conserving water. Dry clod analysis showed that there was a tillage system-soil type interaction effect on clod size, a factor in both seed germination and water management.
Soil tests revealed that much of the surface applied phosphorus and potassium remained in the top two to three inches of the soil profile after two years of no-plow tillage.
An economic evaluation, using the linear programming technique, showed that the most important factor in increased profits with the no-plow systems was more timely planting. The effect of tillage system on other enterprises,
PURDUE UNIVERSITY • Agricultural Experiment Station • Lafayette, Indiana