Effects of different conservation tillage measures on spring maize yield and soil fertility in the Loess Plateau

This research is based on the implement of tillage and no-tillage farming with straw mulching,plastic film mulching,straw and plastic film mulching or without mulching to study the changes of spring maize yield and soil fertility.The result shows: On the basis of tillage without mulching spring maize yield is 6 212.75 kg/hm2,straw mulching increases yield by 45.67% compared with no mulching,plastic film mulching increases yield by 47.24%,straw and plastic film mulching increases yield by 73.24%;On the basis of no-tillage with straw mulching the yield increases only by 3.07% compared with no mulching,and plastic film mulching increases yield by 28.91%,while straw and plastic film mulching increases yield by 38.74%.Compared with tillage farming,no-tillage farming increases yield by 19.69% in no mulching condition,but it decreases yield by 15.31% in straw mulching condition.Under the same farming method,water use efficiency trend is straw and plastic film mulchingplastic film mulchingstraw mulchingno mulching,water use efficiency of no-tillage farming reduces at an average of 11.56% compared with tillage farming.Soil organic matter content under straw mulching rises by 0.62 g/kg compared with no mulching while that under plastic film mulching drops by 0.30 g/kg.The content of available P under plastic film mulching is the lowest,it declines at an average of 2.93 mg/kg compared with no mulching.The content of available K of no-tillage farming increased 9.54 mg/kg compared with tillage farming,but there is no significant changes of total P.