Conservation tillage effects on soil properties and yield of corn and soya beans in Indiana

Abstract

Long-term studies have been conducted on 7 soils throughout the state of Indiana, to determined the effectiveness of a range of tillage systems in producing high crop yields while reducing erosion and improving soil physical properties. The soil studied included one sandy loam, one loam, three silt loams and two silty clay loams with a range of organic matter contents and slope and drainage classes. Tillage systems studied included conventional moldboard plow, chisel plow, disking, ridge till-plant and no-till. Conservation tillage systems resulted in higher soil water contents, lower soil temperatures, more organic matter and more water-stable aggregates near the surface, and higher bulk densities than conventional tillage systems. On sloping, well-drained, low organic matter soils, conservation tillage produced corn ( Zea mays L.) yields that were equal or better than yields from conventional tillage. On poorly-drained, low organic matter, poorly structured soils, the soil structure under conservation tillage tended to improve with time as soil organic matter and aggregation increased. Corn and soya bean ( Glycine max) yields have also improved with time and often exceed those from conventionally tilled soils. On poorly drained soils high in organic matter that were cropped to continuous corn, conservation tillage generally yielded less than conventional systems due to low soil temperature and excess wetness in spring. Significant interactions of tillage systems and crop rotation existed on the two poorly-drained soils on which rotation was an experimental variable.