施加粪肥对潮土有机磷形态转化的影响

施加粪肥是提高土壤肥力的重要措施，为了解粪肥磷在潮土中的化学行为，通过室内培养试验，采用NaOH-EDTA 浸提和 31P 核磁共振技术分析比较了鸡粪、牛粪及施肥后土壤中的磷形态及含量，并研究了施肥对潮土有效磷的影响。结果表明，粪肥磷主要以无机态形式存在，2 种粪肥的有机磷形态及含量有明显不同，肌醇六磷酸在鸡粪中的含量明显高于牛粪。粪肥施加到潮土后丰富了土壤有机磷的形态。随时间延长，潮土中各形态磷发生相互转化，以肌醇六磷酸为主的正磷酸单酯含量明显降低，核酸等正磷酸双酯显著升高。鸡粪处理的土壤有效磷含量逐渐升高，牛粪处理则表现出相反的趋势。施加粪肥后，土壤有效磷呈现不同的变化规律可能是无机磷在土壤中固定或沉淀，有机磷矿化和无机磷被微生物固持这三方面综合作用的结果。

Transformation of Phosphorus Forms in Calcareous Soils with Manure Application

Manure application is an important management practice to improve soil fertility. In order to understand the phosphate chemistry in manure-amended calcareous soil, the extractant of NaOH-EDTA and 31P nuclear magnetic resonance(31P-NMR)spectroscopy were conducted to study and compare phosphorus forms and contents in poultry manure, cattle manure and manure-amended soils. Moreover, effects of manure application on soil available phosphorus were also investigated. The results showed that large percentage of the phosphorus in manure was in the inorganic form. The two manures differed in their P composition. Much more phytate was detected in poultry manure compared with cattle manure. Application of manure changed the organic phosphorus forms in soil. Additionally, transformation of phosphorus forms in soils was observed with incubation time. Content of orthophosphate monoester such as phytate decreased while orthophosphate diesters such as nucleic acid increased obviously. With incubation time, the content of soil available phosphorus increased in poultry manure treatment while it declined in cattle manure treatment. Different variations of soil available phosphorus after manure application might be the synthesis results of phosphorus fixation-precipitation, mineralization and immobilization.