Deep tillage with organic materials returning to field improving soil physical characters of calcic chernozem

Effects of 3 deep tillage modes including deep loosing (DL), tillage with straw return in subsoil (TSR) and tillage with straw and chicken manure return in subsoil (TSCR) on physical characters of different soil layers were studied at Calcic Chernozem in Anda City, Heilongjiang Province in order to explore the soil improvement effect of different deep tillage modes using the normal tillage (CK) as the control. TSR and TSCR were cultivated by soil replacement plough from proprietary research. The results of field experiment showed that the change of soil solid phase radio of each treatment was irregular in topsoil, and TSR and TSCR decreased obviously under 20 cm layer; water contents of different soil layers of the deep tillage treatments were all higher than that of CK treatment, the difference was obvious in >30-50 cm depth, and the order of soil water content was TSCR>TSR>DL>CK.