Abstract: In order to find a suitable method for returning rice straw in North China and to provide theoretical support and data reference for it,the effects of adding decomposed straw (F),rice straw-derived biochar (S) and non-decomposed straw (Z) on the total phosphorus content,available phosphorus content and inorganic phosphorus forms in coastal saline paddy soil were investigated by using an indoor constant temperature and flooding incubation method.The results showed that the addition of three different treated straw increased the contents of total phosphorus (P) and available P in the soil.The increasing effect of adding straw biochar treatment was the most significant among them.With the prolonging of culture time,the content of total phosphorus in soil decreased slightly,while the content of soil available phosphorus increased first and then decreased.Compared with control (CK),the addition of different treated straw increased the contents of Ca₂-P,Ca₈-P and Fe-P with 63.72%,60.07% and 9.34%,and the contents of O-P and Ca₁₀-P decreased in different degrees 28.17% and 6.54%,respectively,among inorganic phosphorus forms.Overall,the addition treatments of rice straw-derived biochar,decomposed straw and non-decomposed straw could activate soil phosphorus through transforming the inorganic phosphorus forms and increasing the content of soil total phosphorus and available phosphorus.The adding rice straw-derived biochar got the most remarkable activated effect.The activated effect of them was as follows:S > F > Z.

Key words: Rice straw-derived biochar, Coastal saline paddy soil, Soil total phosphorus, Soil available phosphorus, Soil inorganic phosphorus form

CLC Number: 

• S141

• S511.01