Abstract:According to the characteristics of coastal saline soils in Jiangsu Province,the effects of four soilamendments were studied.Through single application of amendments and combined application of amendments and gypsum,soil salt content,soil pH value,and the output of crops were measured after the application of the amendments.The best amendment and combination suitable to the coastal soil in research areawere selected.Results from the experiment showed that the effect of humic acid on the coastal saline soil wasthe best and after the treatment of humic acid(300kg/hm2),the relative amounts of salt content in the soillayers of 0-5,5-20and 20-40cm decreased by 38.2%,24.5%,and 13.9%,respectively.Gypsum couldsignificantly decrease the soil salt content and increase the outputof crops.After the treatment of gypsum(300kg/hm2),the relative amounts of salt content in the soil layers of 0-5,5-20and 20-40cm decreasedby 18.8%,13.0%and 4.9%,respectively,and the yield of rape increased by 6.1%compared with that ofCK.The combined application of Humic acid and gypsum was the best combination to the coastal saline soil.After the treatment of humic acid(300kg/hm2)combined with gypsum(300kg/hm2),the relative amountsof salt content in the soil layers of 0-5,5-20and 20-40cm decreased by 45.1%,38.9%and 25.7%,respectively,and the yield of rape increased by 18.6%compared with that of CK.