Effects of Tillage Practices on the Variation of Soil Moisture and the Yield of Summer Maize

Field experiments from 1996 to 1997 growing seasons were conducted to determine the effects of conventional tillage (CT), no tillage (NT) and subsoiling tillage (ST) practices on the soil water situation and the crop yield. Compared with the conventional tillage method, no tillage practice maintained higher soil water storage in the upper profile during the early part of the growing season. The gain was attributed to decreased evaporation losses caused by a straw stables cover and undisturbance of the surface soil under no tillage condition, as well as a change in pore size distribution in the untilled soil. On the other hand, storage in the subsoiling soil was obviously less than that of the conventional tillage soil because soil physical properties in the deep tilled soils were largely altered. As growing up of summer maize, few differences in soil water distribution were observed among the three tillage methods. The effects of different tillage methods on increase of crop yield were evident.