| In this paper taking the cotton field in northern Xinjiang under perennial drip irrigation below membrane as the research object, has discussed the effects of the soil temperature change to the soil water and salt moving rule in cotton field during whole growth period, also carried out the optimal adjustment for the irrigation schedule. The research results showed that: The soil temperature will be increased with the air temperature rise, reduced with the air temperature decrease. But the air temperature impacting function will be attenuated with the soil depth increasing, also the lag time will be extended with the depth increases. Before August, the soil temperature showed a decreasing distribution from top to bottom, with the increase of soil temperature, the soil water diffusivity kept a unceasing increase, the soil water-holding capacity kept a unceasing decrease, so caused the soil water content decrease at 5 to 60 cm, while the soil water content increased at 90 to 150 cm, resulted in the soil salinity was relatively higher at 5 cm and 90 to 150 cm. After August, with the decrease of the soil temperature, the distribution of soil temperature occurred change. The soil water diffusivity kept unceasing decrease and the soil water-holding capacity kept unceasing increase. The transpiration of soil moisture reduced and deep percolation decreased. The moisture content in each soil layer was kept relatively higher and the soil salinity in each soil layer was kept relatively lower. Under the condition of unchanged irrigation quota, in May and June, relatively reduce the irrigation quota, but in July and August, relatively diminish the irrigation interval and increase the irrigation quota. After August, relatively increase the irrigation interval, reduce the irrigation quota, at the end of growth period, increase the irrigation quota, which has a significant role for washing soil's salt and suppression of soil salinity. |