Effects of No-tillage and Straw Mulching on Soil Nutrient Content and Drought Resistance of Maize on Dry Land

Effects of different cultivating measures(tillage and no-tillage)and different straw mulching amount(no,half and full) on soil nutrient content and drought resistance of maize on dry land in Hunan Province were studied,and the main results are as follows: ①Straw mulching promoted growth and development of maize in normal year(2004),but it lightened the effect of high temperature and drought and prolonged filling stage 2~4 d in high temperature and drought year(2005).Cultivating measures affected growth and developmental process slightly,but no-tillage could prolong growth duration about 2 d under high temperature and drought condition.②Straw mulching heightened plant height,leaf area,dry matter weight,1000-grain weight and yield,and the effects of full-straw mulching were better than those of half-straw mulching.Under condition of the same straw mulching amount,the effect of tillage was better than that of no-tillage.③Content of organic matter,fast-available K and available P in soil were heightened by straw mulching,which was more evident under no-tillage condition,but soil organic matter content was decreased slightly under no straw mulching condition.④Soil water content was heightened by straw mulching,and the effect of full-straw mulching was better than that of half-straw mulching.These results showed that straw mulching could alleviate the harm of drought at a certain extent,at the same time it could heighten soil nutrient content,moreover,the effect of combining straw mulching and no-tillage on heightening soil nutrient content was more evident.