Objective Through continuous monitoring of soil water, heat and salt quantities in a single irrigation cycle of a drip-irrigated cotton field under the membrane, the aims were to grasp the transport law of their changes in the soil body over time, and to explore the interaction relationships among them.

Methods The soil water content and salt content of each layer were measured by using Time-T3, while the soil temperature was detected synchronously by using an eight-channel alarm temperature recorder.

Results The water content of each soil layer with the time change trend was basically the same. After irrigation, soil water gathered in the cotton row below the root system near. The salinity of the soil below the drip head was the most significant. The end of a single irrigation cycle, the soil below the drip head presented desalination phenomenon, while the soil between the membrane and the cotton row presented salination phenomenon. The irrigation water had a significant impact on soil temperature. After a single irrigation cycle, the soil temperature below the drip head showed a significant drop first and then slow down. ④The temperature of soil below the drip head showed a significant drop first and then slow down. After a single irrigation cycle, the soil temperature showed a significant decrease and then a slow increase, while the soil salinity did not significantly affect the temperature. The power index correlation coefficient of soil water content, salinity and time showed an increase and then a decrease in the depth of the soil layer.

Conclusion There are differences in the quantity of water, heat and salt in each soil layer in a single irrigation cycle. With the extension of the end time of irrigation, water plays a dominant role in checking and balancing, and its spatial and temporal distribution is significantly affected by the crop root system. So its spatial change characteristics can be utilized to predict the soil moisture content in an arbitrary irrigation cycle in the same case, and to provide a fine irrigation system.