Effect of Eight Tillage-Planting Systems on Soil Temperature, Percent Stand, Plant Growth, and Yield of Corn on Five Indiana Soils

In the mid-1960‘s farmers were considering no-plow tillage as a way to cut production costs and achieve more timely planting, and environmentalists were promoting conservation tillage as a primary means of cutting erosion losses. There was an obvious need for a more detailed evaluation of where no-plow tillage methods were adapted in the Corn Belt. The objective of this research was to determine corn (Zea mays L.) production potential of tillage systems that varied in amount of residue cover and surface roughness on a range of soil types and in different climatic situations. Chisel, till, strip rotary, and strip coulter planting systems were compared with conventional and limited tillage on plowed ground from 1967 through 1970. Experiments were located on sandy loam and loam soils in northern Indiana, silt loam and silty clay loam in eastern Indiana, and on a high silt soil in southern Indiana. There was a latitude range of 290 km in experiment locations. Percent stand was 80% or higher with all systems on sandy loam and loam soils. Chisel and rotary on silt loam, and wheel track, chisel, till and rotary systems on silty clay loam produced 65 to 70% stands and were significantly below conventional at the 5% level. Soil temperature at I0 cm for the first 8 weeks after planting for coulter vs conventional planting was 3.8 C lower in northern Indiana and 2.7 C lower in southern Indiana. However, mean soil temperature for all systems was 3.7 C higher in southern Indiana. Systems with intermediate tillage had intermediate soil temperatures. Corn growth at 8 weeks after planting with no-plow systems was delayed in northern and eastern Indiana, compared to conventional tillage, with strip rotary and coulter systems having slowest growth. Coulter and strip rotary systems produced fastest corn growth from 4 to 8 weeks after planting in southern Indiana. Four-year mean grain yields show a 1000 kg/ha advantage for till planting, but no significant variation among other systems on sandy loam (northern Indiana). The yield increase for till planting may have been due to the ridging done at cultivating time. Other systems were not cultivated. At the same location on poorly drained dark loam, yields from strip rotary and coulter systems were significantly lower, at the 5% level, than grain yields from other systems. On poorly drained fine-textured soils in eastern Indiana, mean yields for all no-plow systems were lower than mean yields for plow systems, partly due to poor weed control. Four-year mean yields on the rolling silt loam soil in southern Indiana were not significantly different, although differences among systems within each of the 4 years were significant at the 5% level. Results indicate that with good management, chisel, till, strip, rotary, and coulter systems are adequately adapted on the rolling high silt soils of southern Indiana and on well-drained loam or sandy loam soils in central and northern Indiana. The no-plow systems, as used in these tests, were not adapted on poorly drained, fine-textured soils, although chiseling appeared to be competitive with conventional tillage when stands were adequate.