Conservation Tillage Effects On Water Use Of 2 Phases Rotation Systems With Spring Wheat And Field Pea In Dryland

This paper selects the Dingxi specific semiarid hilly areas in the middle of the Loess Plateau．Based on the former experiment practice,study on conservation tillage on soil water dynamic,crop dry matter and yields,water use efficiency etc,of 2 phase rotation systems with spring wheat and field pea,by the field experiments in dryland in 2002-2004．The results show: 1 The season and vertical dynamic ofwater storage in 2m soil profile are similar under ．conservation tillage and traditional tillage． 2 No-tillage with straw mulch enables to increase moisture retention．According to this paper,water storage normally increased by 7．02％一24．29％． 3 No—tillage with straw mulch enables to increase soil moisture by 0．53％-11．26％． 4 Different rotation sequences have different effects on water storage and soil moisture．Water storage increased by 2 1．72％-30．36％and 20．1 3％-30．92％respectively under 2 phases rotation systems．All of soil moisture of crops for rotation with field pea is higher than crop lower limit(CLL)． 5 Conservation tillage and rotation system are able to enhance soil porosity and infiltration rate． 6 Dry matter in later phase．Crop dry matter is increased by 7．1 6％一54．05％under crops for rotationwithfieldpeathanthatwith springwheat． 7 No-tillage with straw mulch Can increase the crop yield and water use efficiency．Compared with traditional tillage,they increased bY 30．28％and 40．08％respectively．...