Effects of saline water irrigation on winter wheat and its safe utilization under a subsurface drainage system in coastal saline-alkali land of Hebei Province, China

Fresh water shortages are severally restricting sustainable agriculture development in coastal saline-alkali land in Hebei Province, China. Saline water used for irrigation can increase crop yields as well as the risk of soil salinization. To identify safe and simple ways of using saline water in this region, a continuous two growth period of winter wheat field study was conducted from 2016 to 2018 to evaluate the effect of saline water irrigation on soil salt and winter wheat yield under a subsurface drainage system. This study comprised three treatments (non-irrigation, freshwater irrigation, and 6 g/L saline water irrigation), with winter wheat irrigated at the jointing-heading stage. The results indicated that the yield of winter wheat under the irrigation treatment was more than 1.5 times than that of rainfed winter wheat, and there was no significant difference between the yield under freshwater and saline water irrigation. The soil salt content decreased yearly after saline irrigation treatments. Based on subsurface drainage system, two consecutive years of saline water irrigation would not cause salt accumulation in the soil, and has increased winter wheat yield. This makes safe utilization of saline water resources realized. Saline water irrigation is equivalent to an increase of 600 m3 of irrigation water resources per hectare. The results provided scientific basis for the safe utilization of saline water resources, grain yield guarantee, and soil sustainable development in coastal area of Hebei Province.