添加稻草生物炭对水稻土磷含量和形态的影响

Effects of Rice Straw-derived Biochar on Phosphorus Content and Form in Paddy Soil

为了探明北方水稻土适宜的秸秆还田方式,并为稻草合理还田提供理论支持和数据参考,采用室内恒温淹水培养法,研究了添加腐熟稻草(F)、稻草生物炭(S)、未腐熟稻草(Z)对北方滨海盐渍型水稻土全磷含量、有效磷含量和无机磷形态的影响。结果表明,添加3种不同形态稻草处理均提高了水稻土全磷和有效磷含量,其中,添加稻草生物炭处理的效果最明显。随着培养时间延长,水稻土全磷含量呈现略微下降趋势,而水稻土有效磷含量呈先上升后下降的趋势。与对照(CK)相比,添加不同形态稻草的处理均提高了水稻土无机磷组分中Ca_2-P、Ca_8-P和Fe-P含量,而O-P和Ca_(10)-P含量均不同程度地降低。其中,添加稻草生物炭处理的效果最明显,Ca_2-P、Ca_8-P和Fe-P平均含量分别提高了63.72%,60.07%,9.34%;而O-P和Ca_(10)-P平均含量分别降低了28.17%,6.54%。总之,稻草生物炭、腐熟稻草和未腐熟稻草施入土壤后,通过促进土壤各种形态无机磷间相互转化和提高土壤磷含量而活化了土壤磷,其中添加稻草生物炭处理的活化效果最好,其次为腐熟稻草,再次为未腐熟稻草。

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 Ca_2-P,Ca_8-P and Fe-P with 63. 72%,60. 07% and 9. 34%,and the contents of O-P and Ca_（10）-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 contentof 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.