Effects of water application intensity of micro-sprinkler irrigation and soil salinity on environment of coastal saline soils

Abstract

To achieve the greatest leaching efficiency, water movement must occur under unsaturated flow conditions. Accordingly, the water application intensity of irrigation must be chosen carefully. The aim of this study was to evaluate the impact of the water application intensity of micro-sprinkler irrigation on coastal saline soil with different salt contents. To achieve this objective, a laboratory experiment was conducted with three soil salinity treatments (2.26, 10.13, and 22.29 dS/m) and three water application intensity treatments (3.05, 5.19, and 7.23 mm/h). The results showed that the effect of soil salinity on soil water content, electrical conductivity, and pH was significant, and the effect of the water application intensity was insignificant. High soil water content was present in the 40–60 cm profile in all soil salinity treatments, and the content was higher in the medium and high water application intensity treatments than in the low-intensity treatment. Significant salt leaching occurred in all treatments, and the effect was stronger in the high soil salinity treatment and medium water application intensity treatment. In the medium and high soil salinity treatments, pH exhibited a decreasing trend, with no trend change in the low soil salinity treatment, and the pH value was higher in the medium water application intensity treatment than in the other two treatments. These results indicated that the three intensities evaluated had no statistically different effect on the electrical conductivity of saturated soil-paste extracts (EC) in the upper 20 cm of the soil profile, and it would be better to maintain a lower value of the water application intensity.