Feasibility study of adopting controlled drainage in Yinnan irrigation district based on salt and water balance

Yinnan Irrigation District widely exists excessive drainage, which poses potential environmental risk downstream. Controlled drainage can be used to reduce the drainage rate for the current system. The feasibility of the application of controlled drainage based on the local weather, geography and soil conditions was studied. The monitoring data during the last 19 years show that the district is in a desalinized state, and the soil salt content from controlled experiment is lower than crop tolerance values. Therefore, adopting controlled drainage in Yinnan Irrigation District is a highly viable option in controlling agricultural pollution.