The results from pot experiment for continuous seven years showed that,the application of 15,30,45,60,90 t/ha of organic manure decreased the soil bulk density of soda saline-alkali soil,increased total soil porosity;the returning of maize straw of 2,4,6 t/ha to soil decreased soil bulk density,increased total soil porosity.Applying organic manure and returning maize straw to soil both enlarged soil reservoir,decreased the soil p H values,increased the contents of soil organic matter,soil hydrolysis N,avail...