Experimental Study Of Drip Irrigation Rotation Brackish Timing Optimization

Development and utilization of brackish water resources for agricultural irrigation and ease the watercrisis caused by the shortage of fresh water resources has become another trend of Agricultural waterconservation in Xinjiang. In recent years, domestic and foreign experts have more research on brackishwater irrigation and drip irrigation, but the combination of the two, and fewer experimental study on thisbasis to use of different plant growth stages of the sensitivity of brackish water to optimize brackish waterDrip Irrigation Rotation, and it still lack of evaluation for brackish water saving irrigation agriculturecomprehensive benefits system.This article study on Xinjiang’s main cash crops–cotton,in the salt content of0.2g/100g loam, eightprograms of brackish (3.3g/L±0.2) Rotation field trials were be designed. Analysis focused on the effects ofdifferent timing of brackish water irrigation on soil salt, crop conditions and yield. And through theestablishment of a comprehensive benefit evaluation index system for brackish water irrigation, everyprograms’comprehensive benefits were be rated, the optimal solution brackish Rotation was be selected bythe comprehensive comparison. The results provide a theoretical basis for reasonable application ofbrackish Rotation in farmland. The main conclusions are as follows:(1) With the increase in the number of brackish water irrigation period, soil moisture tends to decrease,salt accumulation in soil conditions have aggravated the trend. In the same number choice of the period ofbrackish water for irrigation, irrigate the freshwater in the prophase throughout the crop growth period, andirrigate the brackish water late will be better. In addition, salt and water movement changes strong with theseasons, impact of soil properties, rainfall, evaporation and irrigation. As long as the drought years, theprogram which designed in this article will not produce a more serious condition of soil salt accumulation.(2) Cotton’s early growth stage (seedling, bud stage) are more sensitive to water, irrigate thefreshwater in this period can ensure the adequate nutrition growth of cotton, and irrigate the brackishsuitable in the late growth stage (Boll, boll opening stage) can inhibit the vegetative growth of the plantsmoderately. This part of the nutrition transferred to reproductive growth is conducive to high-yield cottonbeads. In the eight scenarios, Scenario4(ddxx) have the highest relative yield rate,7.3%in2012,8.51%in2013.(3) By building on the comprehensive benefits of brackish water irrigation system, selected14evaluation ultimately, and the data will be standardized by the generalized linear efficiency coefficientmethod, distribution of index weights will use AHP analysis, and finally use the mathematical models toevaluate every programs.(4)The value of eight programs’economic, environmental, social, and comprehensive benefits score in2012and2013showed that: the comprehensive benefits scores of Scenario4(ddxx) were significantlyhigher than other programs in2012and2013（0.8339in2012,0.8457in2013）, and it can take into accountthe economic, environmental and social benefits better, have a continued upward trend in the dynamicchanges in time, considering the ideal. Thus Scenario4(ddxx) is selected as the optimal solution brackishRotation.