Soil salt movement and regulation of drip irrigation under plastic film in arid area

Drip irrigation under plastic film had applied for more than 1.6×106 hm2 in Xinjiang, and the area was still increasing. In order to research soil salt movement of drip irrigation under plastic film in arid area, a series of tests had been carried out on mulched drip irrigation in Korla prefecture, located in the south of Xinjiang. According to the experimentations, some characteristics of drip irrigation under plastic film were discovered. After one times drip irrigation, the salt content of soil profile redistributed again and desalted zone, salt immovability zone and salt accumulation zone were formed. The results of calculation showed that the area of desalted zone were bigger than that of salt accumulation zone. Salt mainly accumulated under 40 cm layer or open filed area. Between depths of 0-40 cm, the effects of salt distribution by using double drip pipe were bigger than by using single drip pipe. Between depths of 0-80 cm, the effects of salt distribution by using single pipe were bigger than by using single double pipe. In the period of cottons growth, the profile salt content showed the trends of decrease under the action of periodic drip irrigation. And, a helpful micro-environment to cottons was formed. Thus, the drip irrigation under plastic film was not only a kind of accurate irrigation, but also could regulate soil salt on shallow profile under the field scale in crop growth and development period. This new approach could provide technical support for saving water and decreasing salt in arid area.