Abstract:To make effective use of shallow ground saline water resource for relieving the water crisis in Hebei Low Plain, a three-year field experiment was conducted to study the effects of irrigation with saline water of different salinities on soil water and salt contents, soil evaporation, stage water consumption of cotton, seed cotton yield and water use efficiency. The experiment included four treatments with different salinity levels of 1g/L, 3g/L, 5g/L and 7g/L of irrigation water, which were denoted as S1, S2, S3 and S4. Results showed that during cotton growing period, soil water and salt contents were increased with the increment of irrigation water salinity, especially for soil salt content. Significant differences of soil water and salt contents for each treatment were appeared during experimental years. In wet years, soil water content of root zone was high and a large proportion of salt was leached out; while in arid years, soil water content in root zone was low and salt was accumulated. After threeyear continuous irrigation with saline water, soil salt content in cotton root zone was not accumulated year by year. During the whole growth period, average soil evaporation intensity was higher in S3 and S4 treatments than that in S1 treatment, but there was little difference between S1 and S2 treatments. Irrigation with saline water of salinity lower than 7g/L had a certain influence on cotton water consumption process, but the differences in total water consumption were not significant. S2 treatment obtained the highest average seed cotton yield and water use efficiency, which was followed by S1, S3 and S4 treatments. Compared with S1 treatment, the average seed cotton yield and water use efficiency of S2 treatment were increased by 2.43% and 1.15%, and those for S3 and S4 treatments were decreased by 1.67% and 0.25%, 8.88% and 7.31%, respectively. There were no significant differences in seed cotton yield and water use efficiency among S1, S2 and S3 treatments, however, those for S4 treatment were significantly reduced. The study can provide important theoretical support for developing the use of shallow ground saline water resource in cotton irrigation.
