Studies on Water-salt Dynamics and Balance of Cotton Crops Land in Tarim Irrigation Region

Based on the experimental data of cotton crops land in Tarim Basin,it is described that the water movement and salt transport in arid cotton crops land under different irrigation norms and different irrigation methods.The related water-salt balance problems in irrigated farmland are also discussed in this paper.The main conclusions are as follows: ①the salt is accumulated in the 0～60 cm soil layer under drip irrigation or ditch irrigation with the 2700 m~3/hm~2 irrigation water during cotton growing period.The salt accumulated rate is 12.4% for under-film drip irrigation and 3.4% for ditch irrigation.②It is universally existed that the salt accumulated in the 100cm soil layer during cotton growing period when the irrigation water is less than 6000 m~3/hm~2 with ditch irrigation.③For the new cultivated wasteland with higher initial salt content,salt leaching results is better than the old farmland with lower salt content when the irrigation water is same.④For keeping the water-salt balance in extremely arid agriculture land,irrigation is necessary during the noncrops growing season for salt leaching purpose.