Abstract:
Abstract: Sprinkler irrigation, as one of the useful technologies for the development and utilization of saline soils, has been extensively used in coastal saline soils. However, few studies have been related to the effects of water application intensity on movement of water and salt transport under sprinkle irrigation in this region. A soil-column experiment was carried out to investigate the effects of water application intensity on the movement of wetting front, water redistribution characteristics and salt leaching of coastal highly-saline soil. The experiments included two kinds of coastal highly-saline soils (clayey and sandy) and five water application intensity treatments, in which the sprinkle irrigation was controlled at 1.72, 3.13, 5.27, 8.75 and 10.11 mm/h, respectively. The results showed that under sprinkle irrigation, the water application intensity and soil clay content significantly influenced the movement of the soil-wetting front. With the increase of water application intensity, the driving velocity of the wetting front increased, while the moist depth decreased. To some extent, the soil clay content had a negative effect on the movement of the wetting front. With the redistribution of the soil moisture, the volumetric moisture content of the same depth was largest at the water application intensity of 3.13 mm/h in clayey highly-saline soil, while in sandy highly-saline soil, the most optimal water preserving capability was observed at the water application intensity of 1.72 mm/h. After sprinkler irrigation, the salts in the upper soil layer were well leached, and moved down to the subsoil, where the soil salt content increased sharply to reach maximum. The suitable water application intensity of sprinkler irrigation was different on these two kinds of soils. Among the five treatments, the best leaching effect was obtained at the water application intensity of 3.13 mm/h in clayey highly-saline soil, and 8.75 mm/h in sandy highly-saline soil. This research is meaningful for completing sprinkler irrigation technology to best utilize coastal saline soil, and it will provide a theoretical basis and technical support for developing a complete and systematic technology of water-salt regulation by sprinkler irrigation.