Experimental Research On Cotton Irrigation Schetual Of Under-Film Drip Rotatting Irrigation With Saline Water And Fresh Water

Water resources is the indispensable natural resources for human survival and development. With the development of domestic economy, the demand for water is greater and greater, at the same time the requisition for water quality is higher and higher. Saline water is distributed extensively in the underground of Hebei plain. The mean value of the underground saline water resources amount is 2,135 million m3. Now, though underground fresh water is exploited excessively, saline water utilization is only about 10% at present. Although some area has already utilized saline water for irrigation, improper irrigation method and incorrect irrigation system lead to the fact that salinity accumulated continuously in soil at some areas, and the production decreased. So, it is significant that the saline water utilization should be guided by science.Cotton is planted and distributed widely in Hebei province. The water resources is wasted seriously because that the irrigation methods rely mainly on furrow irrigation still, and this aggravated the fresh water using pressure; Under-film drip irrigation has the advantages of the covering ground film and drip irrigation, it has good regulation on the water, hot state and salinity in soil. Through the wide application of this irrigation system in the Northwest, this technique has already proved that it has the results of saving water, controlling salinity and raising yield.The technique of under-film drip irrigation with saline water is mainly researched in the subject "The cotton under-film drip irrigation technique with mixed fresh water and saline water". The utilization of saline water in shallow layers and fresh in deep layers fully, is the technique of the rotating or mixing irrigation with fresh and saline water, it conclude the mixing proportion and irrigating quota on each application. According to the experimental result, the cotton crop-saline water production function in Hebei province is simulated, and the crop-water-salinity collaborated production function is established and simulated. At the same time, the rotation irrigation schedule with fresh and saline water is working-out. It offered the basis for the scientific control of salinity and water in soil.On the basis of the above work, when the technique of the cotton under-film drip rotating irrigation with fresh and saline water is carried out, a series of problems may...