Experimental study on soil water-salt movement and irrigation scheduling for cotton under mulched drip irrigation condition

Field experiments were conducted to investigate the dynamic regimes of soil moisture and salt as well as irrigation scheduling for cotton under mulched drip irrigation condition. Seven irrigation treatments with different total irrigation amounts (TIA) and irrigation intervals were designed. The results show that soil moisture decreases and soil salt increases as the distance from drip tape increases in horizontal direction. In irrigation periods, areas close to drip tape are in desalting process and areas away from drip tape are in salt cumulating process. The higher TIA leads to higher soil moisture while the irrigation water use efficiency will be lower. Either longer or shorter irrigation interval result in unfavor conditions for growth and yield of cotton. Under sandy soil condition, the maximum yield of cotton occurs when TIA is 675 mm and irrigation interval is 7d, the maximum irrigation water used efficiency occurs when TIA is 375 mm and irrigation interval is 7d.