The Impact Of Conservation Tillage On The Soil And The Maize Under Simulated Rainfall

In the semi-arid, sub-humid area in loess plateau, water is still a restriction factor of cropgrowth and heigh yield, the measure of conservation tillage can effectively retains the soilmoisture content, affects the physical structure and the nutrient content of soil, and thusimpacts on maize growth and yield. In order to explore the effects on the soil water, nutrient,maize growth and yield, we make the reseach about the effect by no-till with straw mulchunder different simulated rainfall in specimen area in north school of North West Agricultureand Forestry University. In this study, we got following conclusions:1The conservation tillage no-till with straw mulch can effectively improve the soilmoisture content. In the whole corn growth period, the soil moisture content of1m soil layer,the treatment no-till with straw mulch9000kg/hm²and the treatment no-till with straw mulch13500kg/hm²were higher than the treatment tillage on11.36%,12.36%under270mmrainfall, were higher than the treatment tillage on11.21%,9.77%under330mm rainfall, werehigher than the treatment tillage on13.85%,26.89%under400mm rainfall.2Under270mm simulated rainfall, no-till with straw mulch can improve the soil organicmatter, available P, available K content to the treatment tillage, but the available N contentreduces. Under330mm simulated rainfall, the soil organic matter content is higher, and theavailable N, available K content is lower than the treatment tillage, the available Phigh-to-low is no-till with straw mulch13500kg/hm², tillage, no-till with straw mulch9000kg/hm². Under400mm simulate rainfall, the impact of cultivation treatment on the soilnutrient is disorder.3Under the simulated rainfall400mm, no-till with straw mulch can reduce the CO₂emission flux in soil. Under the simulated rainfall270mm and330mm, the treatment no-tillwith straw mulch9000kg/hm²can reduce the CO₂emission flux in soil, but the treatmentno-till with straw mulch135000kg/hm²can increase the CO₂emission flux in soil,4The treatment no-till with straw mulch can improve the and leaf area index of maize.In the maturity stage of maize, the plant height under the treatment no-till with straw mulch9000kg/hm²and the treatment no-till with straw mulch13500kg/hm²were higher than thetreatment tillage on23.06%,20.44%under270mm rainfall, were higher than the treatmenttillage on12.43%,19.58%under330mm rainfall, were higher than the treatment tillage on 4.07%,23.12%under400mm rainfall.The LAI （leaf area index） of maize under the treatment no-till with straw mulch9000kg/hm²and the treatment no-till with straw mulch13500kg/hm²were higher than thetreatment tillage on16.25%,39.57%under270mm rainfall, were higher than the treatmenttillage on42.86%,29.93%under330mm rainfall, were higher than the treatment tillage on15.22%,31.12%under400mm rainfall.5Under the rainfall330mm, the treatment no-till with straw mulch13500kg/hm²has thehighest maize yield by8466.7kg/hm², and the largest water use efficiency by24.94kg/（hm²mm）.