Effects of halophyte and straw mulching on soil nutrients and desalting in extreme saline soil of mud flat areas

ObjectiveThe impacts of planting halophyte and straw mulching on soil nutrients and desalting in ex-treme saline soil of mud flat areas were studied in order to provide reference for soil desalination and amelioration in coas-tal mud flat areas.MethodIn May,2014,four treatments were applied in extreme saline soil(salinity over 10 g/kg)of coastal mud flat areas in Jiangsu:control(CK,bare land),planting Suaeda(PS),15 t/ha straw mulching(SM-A),30 t/ha straw mulching(SM-2A).Meanwhile,soil salinity,pH and soil moisture of 0-10,10-20,20-40,40-60,60-80 and 80-100 cm soil layers and soil nutrient contents of topsoil were determined.ResultCompared with CK,soil salinity at soil depth of 0-100 cm after one year of treatment obviously declined in treatments SM-A and SM-2A(P<0.05,the same below),and soil salinity at soil depth of 0-60,60-80 and 80-100 cm decreased by over 96.0%,84.9% and 55.8% respectively.Soil salinity in PS treatment were significantly decreased by 51.0% at topsoil,but had no significant effects on that at soil depth of 20-80 cm.Compared with CK and PS treatment,one year later,soil pH value at 0-100 cm soil depth and soil moisture content at 0-60 cm soil depth significantly increased in treatments SM-A and SM-2A after one year.Compared with CK,straw mulching treatment could significantly decrease soil organic carbon in topsoil,but they had no significant difference on soil total nitrogen,carbon-nitrogen ratio,bulk and porosity(P>0.05).ConclusionConsidering the desalination and soil fertility improvement,straw mulching combined with applying proper organic fertilizer may be an important measure to promote soil desalination and amelioration in extreme saline soil of coastal areas in the future.