The Research That Impact Of Water Use For Irrigation Under Different Groundwater Depth In Huaihe River Basin

In this study,to research the Huaihe River Basin groundwater efficiency utilization as the core. Firstly, planted the winter wheat and soybean in Shajiang Black Soil and yellow fluvo-aquic soil. Expansion crops use of groundwater under different depth of groundwater. Afterward, calculate ETC, determine the effective precipitation. Final, based on the principle of water balance draw irrigation water for crops under different depth of groundwater. Analysis the impact of irrigation water under different depth of groundwater. The results indicate:(1) For the whole life of winter wheat, two kinds of the soil, the regular distribution of crop irrigation water is very similar under different depth of groundwater. Irrigation water first decrease and then increase with the increase of groundwater depth. Without artificial irrigation water, also can ensure the whole life of winter wheat’s water requirement of normal growth and achieve benefits of the water saving, when the depth of groundwater is controlled about0.6m in Shajiang Black Soil and2.0～3.0m in yellow fluvo-aquic soil.(2) Each of the winter wheat’s growth period, the regular distribution of crop irrigation water is deviate under different depth of groundwater, because of crop growth characteristics, climatic conditions and other factors.In Shajiang Black Soil, each of the winter wheat’s growing stage which the minimum irrigation water are appearing under0.6m depth of groundwater. Yet the minimum irrigation water are appearing under1.0m depth of groundwater in yellow fluvo-aquic soil. In addition,the minimum irrigation water are appearing in yellow fluvo-aquic soil more deeper than in Shajiang Black Soil, besides, The surplus water in yellow fluvo-aquic soil much more than in Shajiang Black Soil.(3)In reviving and jointing period of the winter wheat, we must be carried out artificial drainage to create an aerobic environment for root crops in both soils. Other growth period: when the depth of groundwater is controlled at "0.6m(seedling and reviving period, jointing and heading period),""0.6-0.8m(heading and grain-filling period),""0.8～1.0m(heading and grain-filling period)," in Shajiang Black Soil, the depth of groundwater is controlled at "1.0m(seedling and reviving period),""1.0-2.0m(jointing and heading period, heading and grain-filling period),""3.0-4.0m(grain-filling and ripening period)," in yellow fluvo-aquic soil. What ideal way of water supply that is conducive to winter wheat’s root water absorption and create an aerobic environment and reducing irrigation water.(4)The dynamic changes of irrigation water of winter wheat under different groundwater depth show consistent in both soils.(5)The dynamic changes of irrigation water of soybean under different groundwater depth show "S" in Shajiang Black Soil, and show "V" in yellow fluvo-aquic soil. From the point of view of high yield of crops:In Shajiang Black Soil, the soybean is suitable under1.5m groundwater depth before filling period and requires a small amount of drainage, but it was most advantageous to soybean maturity when the depth of groundwater is controlled at "0.8～1.0m (filling and ripening period)".In yellow fluvo-aquic soil, the soybean is suitable under,3.0m groundwater depth before filling period, other it was most advantageous to soybean maturity when the depth of groundwater is controlled at "2.0-3.0m (filling and ripening period)".(6)Is sufficient to ensure the whole life of soybean water requirement through natural rain-fed mode in Huaihe River Basin. Need to take drainage measures in a timely manner if excessive rainfall during the growth period. The authors suggest that it’s little significance to research of irrigation water of soybean under different groundwater depth in Huaihe River Basin, But should focus on the issues of droughts and flood equilibrium during planting period of soybean.Through this study to guide agricultural irrigation, to control the depth of groundwater, in order to the crop root use groundwater of a greater degree, Improve the utilization rate of groundwater, reduce artificial irrigation, Not only can increase the yield of crops,but also create a water-saving benefits.