Study on movement evolution law of soil water in condition of agronomic water saving irrigation

Solve the problem of study area of agricultural water is the key task for relieving fresh water resource lacking, and straw mulch is the main measure for agronomic water saving in mainland of China, the thesis researches the movement evolution law of soil water in condition of straw mulch on the basis of compared analysis the soil water testing data of mulch test points and non-mulch test points. The research shows that the effect on soil water movement of straw mulch mainly reflect on relative drought period and shallow soil layer, that is to say, soil moisture and soil water potential of mulch test points in drought period are both higher than that of contrast test points, and along with depth increasing, the straw mulch effect weakens. When evaporation mainly is surface inter-naked evaporation, straw mulch will effectively restrain the ineffective evaporation of soil water; when evaporation mainly is vegetation transpiration, the straw mulch obviously promote the transpiration of vegetation. In drought period, straw mulch is not profit for deep soil water infiltration, but advantage for soil water utilization of middle and shallow level (0∼−120cm), however the infiltration speed rate of straw mulch point in high water period is obviously higher than that of contrast point.