Experimental Studies Of Surge Flow Border Irrigation And Furrow Irrigation In Xinjiang

At present, more than 95% of the irrigated field in the whole world and 98% in China use surface irrigation. We carried out an experimental study of surge flow irrigation and furrow irrigation in Xinjiang in summer 2005. Based on the review of national and international research results of surface irrigation, theoretical analysis, and field experiments were conducted to optimize the technical parameters of surge flow border irrigation and furrow irrigation. Major findings are as follows:1. Whether the ultimate length of surge flow advance is equal or more than that under continuous irrigation is decided by parameters of surge flow irrigation when it has the same volume of irrigation water. Period of 2, cycle ratio equals to 1/4 can make a bigger ultimate length of surge flow advance.2. Most of the practical irrigation depth of surge flow irrigation are more than the planned. Based on the analysis of technical parameters of surge flow irrigation, we know that optimum parameters are: period of2, cycle ratio equals to 1/4-1/5, and intake flow rate within 6-7 L/m·s. The whole fields can be irrigated with a small quantity of water.3. Infiltration parameters and Manning roughness obtained by analysis of the advance process of irrigation water indicate that: the roughness factor reduced as the cotton grew. Simulations using SRFR model for technical parameters with surge irrigation performance showed that the appropriate conditions for surge flow irrigation are: cycle ratio equals to 1/4, period of 2, and intake flow rate within 6-7 L/m·s.4. The field experiment was conducted to study the effects of such factors as furrow depth and inflow discharge on surface flow moving characteristics. Inflow discharge and furrow depth are greater, velocity are greater.5. The appropriate inflow discharge is 0.5-1.0 l/s. Only when the volume of irrigation water is more than 4 m3 , each furrow can meet plants needs and was good for soil desalinization.6. Vertical infiltration is greater than horizontal infiltration. Increasing furrow depth was beneficial to increasing horizontal infiltration. The soil salt content will increase when volume of irrigation water is less than 3 m3 each furrow.