Effects of deficit irrigation with saline water on soil water-salt distribution and water use efficiency of maize for seed production in arid Northwest China

In order to explore the utilization of groundwater resource, field experiments were conducted in 2012 and 2013 in the Shiyang River Basin of Northwest China. Altogether nine treatments included three water levels w1, w2 and w3 (1ETc, 2/3ETc, and 1/2ETc, ETc = 555 mm) in combination with three salinity levels s1, s2 and s3 (0.71 g/L, 3 g/L and 6 g/L).Soil water content, soil salt content and yield of maize for seed production were measured for studying the effects of deficit irrigation with saline water on water-salt distribution and water use efficiency of maize for seed production. The results showed that soil water content of saline water irrigation was higher than fresh water irrigation and soil salt content increased with increase of irrigation water salinity under the same irrigation water amount. Soil water content of deficit irrigation was lower than sufficient irrigation and soil salt content increased with decrease of irrigation water amount under the same irrigation water salinity. The soil salt accumulation increased gradually with increase of irrigation water salinity and decrease of irrigation water amount under the combined effect of irrigation water amount and irrigation water salinity. Irrigation with water salinity of 3 g/L and water amount of 370 mm will not cause a substantial yield reduction and could increase water use efficiency of maize for seed production. Irrigation schedule with irrigation water amount about 370 mm and irrigation water salinity below 3 g/L is recommended in this study area. The irrigation schedule of this study can be used in the practice of agricultural production and the results show a reasonably utilization of saline water, thereby supplying theoretical guidance for water-saving irrigation development.