Study On Water Saving Irrigation Schedule In Intercropping Pattern By ISAREG Model In Hetao Irrigation District

Hetao irrigation area is an important food production base, all these situations which facing to vigorously develop water-saving agriculture,subustantially increaing in water use efficiency,and the actual situation of severe water shortage,make the workers aroused much more attention.This paper researched the non-sufficient irrigation schduule of wheat intercroping sunflower wheat intercroping maize based on Comprehensive agricultural water saving demonstration area in Hetao district, using Water Balance Method and Crop Coefficient Approach revealing the water requirement regulation in intercropping pattern, the crop coefficient was determined meanwhile. Also evaluated and optimized the irrigation system in intercropping pattern by ISAREG model,seeking optimal Irrigation Schedule,which can provide the technical support for water saving and optimization management of Hetao irrigation District.By systemic theory analysis and research,some main conclusions were obtained as followings:(1)The change law of the daily water demand:Wheat intercropping maize:Growing animated period of wheat(Middle growth stage of maize> Growth telophase of wheat (Growing animated period of maize)> Middle growth stage of wheat(Early growth period of maize)> Growth telophase of maize>Early growth period of wheat. Wheat intercropping sunflower:Growing animated period of wheat(Middle growth stage of sunflower> Growth telophase of wheat (Growing animated period of sunflower)> Middle growth stage of wheat(Early growth period of sunflower)> Growth telophase of sunflower> Early growth period of wheat. Therefore,whether the water requirements can be satisfied will be very important for ensure high productivity.(2)The change law of crop coefficient of Wheat intercropping maize:Growing animated period of wheat(Middle growth stage of maize> Growth telophase of wheat (Growing animated period of maize)> Middle growth stage of wheat(Early growth period of maize)> Growth telophase of maize>Early growth period of wheat. The change law of crop coefficient of Wheat intercropping sunflower:Growing animated period of wheat(Middle growth stage of sunflower> Growth telophase of wheat (Growing animated period of sunflower)> Middle growth stage of wheat(Early growth period of sunflower)> Growth telophase of sunflower> Early growth period of wheat,(3)When irrigation water only by yellow river water in project area, Optimal irrigation schedule of wheat intercropping maize:irrigation time:The time of incoming water of yellow river, irrigation quota respectively are67mm,67mm,97mm,100mm,110mm. Optimal irrigation schedule of wheat intercropping sunflower:irrigation time:The time of incoming water of yellow river, the irrigation quota for each time is82mm.(4)If outfit the well irrigation in project area, Optimal irrigation schedule of wheat intercropping maize:irrigation time respectively are May14, June5, June23, Julyl5,July25,Apr12,Irrigation quota respectively are67mm,67mm,97mm,67mm,97mm,97mm. Optimal irrigation schedule of wheat intercropping sunflower:irrigation time respectively are Mayl, May24, June19, July13, July31. the irrigation quota for each time is82mm.(5)If outfit the well irrigation also in the condition of we can monitor the soil-water dynamic real-time, Optimal irrigation schedule of wheat intercropping maize: implementing irrigation when the soil water content down to75%of the appropriate moisture content, the water of the root layer reach to90%of field capacity then stop the irrigation, irrigation timing and irrigation times will be optimized by the model.Optimal irrigation schedule of wheat intercropping sunflower:implementing irrigation when the soil water content down to70%of the appropriate moisture content, the water of the root layer reach to90%of field capacity then stop the irrigation, irrigation timing and irrigation times will be optimized by the model.