Conservation tillage for long-term amelioration of plow pan soils

ABSTRACT:

Plow pans that restrict root growth, depriving plants of subsoil water and nutrients, cause problems in developing conservation tillage systems on many soils. Sub-soiling under the row at planting is an accepted practice that often deals effectively with the plow pan problem. But subsoiling requires high energy requirements, has short-term beneficial effects, and leaves an undesirable mix of soil horizons. A deep tillage system that requires less energy than subsoiling, provides long-term amelioration of plow pans, and does not mix soil horizons was investigated. A narrow, vertical slit is cut through the plow pan beneath the row at planting. The slit eliminates soil strength and low soil oxygen as deterrents to roots growing through the pan. Once the slit is filled with organic material from decaying roots, it becomes a lasting feature of the soil profile, promoting root growth through the plow pan for an indefinite period of time.