Effect of saline water for increasing soil water before sowing on helianthus growth and saline distributional characteristics of soil

To study effect of saline water for increasing soil water before sowing on helianthus growth and saline distributional characteristics of soil, the method of coupling pot experiment with field plot experiment had been adopted, and saline water for increasing soil water before sowing had been divided into four levels (3, 4, 5, 6 g/L), fresh water treatment as the contrast. The results show that saline water for increasing soil water before sowing restrain rate of emergence and seeding emergence time to different degrees. When the salinity of irrigation water for increasing soil water before sowing is the same, the rate of emergence of field plot treatment is lower than that of corresponding pot treatment, and seeding emergence time of field plot treatment is longer than that of corresponding pot treatment. The growth of helianthus has not been restrained but stimulated using the saline water which total salinity is 3 g/L. The growth parameters such as plant height, leaf area index and root/shoot ratio are all greater than those of fresh water treatment. Compared with fresh water treatment, the grain number of one disc and hundred-grain weight of 3 g/L treatment are all increased, the rate of unfilled grain decreases by 19.7%, and yield increases by 8.1%. The yields of helianthus which are treated with 4, 5 and 6 g/L saline water decrease by 7.0%, 14.8%, 23.9%, respectively. When growth duration finished, average soil salinity of 0-20 cm soil layer with all treatments is close to initial value without notable desalination or salification phenomena, and 20-40 cm and 40-120 cm soil layer with all treatments are in salification state to different extents, which salification degree increase with the increase of salinity of irrigation water and the deeper soil layer, the higher salt content.