Field Experimental Study On Water And Nitrogen Distributionunder Surge Flow Fertigation

Efficient water-saving irrigation as well as scientific and rational fertilization is of great significance for the sustainable development of agriculture. Considering surface irrigation is the major irrigation method in China, we have conduct field experiments in Xinxiang test base of CAAS(Chinese Academy of Agricultural Sciences), with surge flow irrigation and fertigation as the research objects, soil water and nitrogen distribution as the main research content. This paper aims at discussing the watering effect between surge flow irrigation and conventional irrigation, and studying water and nitrogen distributing characteristics under different fertilization modes, and get the following conclusions: 1. According to the measured data of water advancing test, making water advancing process diagramwith the water advancing distance X as horizontal axis, the irrigation time T as the vertical axis. Wecan draw that water advancing length LS is longer than conventional irrigation when using surgeflow irrigation, and the average velocity of the second period in surge flow irrigation also increasedsignificantly. The reason is that a layer with low infiltration rate has formed on surface soil, making the water flow velocity quickened. 2. Using the power function fitting for the water advancing process of each border check, thecorrelation coefficients are greater than 0.9 with a good fitting effect. But for surge flow irrigation,the effect of fitting is slightly worse in the second period, and the correlation coefficient decreased.This is because that the surface conditions of border check have changed under surge flow irrigation,causing the water advancing process changed. 3. By contrast the conventional border irrigation to the surge flow border irrigation under differentfertilization in field, the results shows that the variation coefficient Cv of soil water spatialdistribution changed little along the long stretch before and after irrigation, while the larger changesin soil nitrate content. This indicating that irrigation has little impact on soil water distributionuniformity, but the influence on nitrogen distribution is greater. 4. After surge flow irrigation, the soil moisture in the 80 ~ 100 cm soil layer changed small thanconventional irrigation, and the uniformity of soil moisture within 0 ~ 60 cm soil layer was betterthan the conventional irrigation. The Christiansen coefficient of soil volumetric water content undersurge flow irrigation is higher than that of the conventional irrigation, indicating that the soilmoisture is more evenly distributed when using surge flow irrigation, especially in the surface soil. 5. By using fertigation method, the uniformity of nitrate content within the 0 ~ 80 cm soil layer isgreatly increased than broadcast fertilization, and the Christiansen coefficient of soil nitrate contentis higher than the spread fertilizer treatment. This illustrate that the application of fertigationtechnology can effectively improve the distribution uniformity of fertilizers in the soil. By usingfertigation with surge flow irrigation, the Christiansen coefficient of water and nitrogen within 0 ~60 cm soil layer is higher than other experimental treatments. We can say that, to a certain extent, water and fertilizer can be preserved by using fertigation under surge flow irrigation.