土地处理系统表层土壤中磷赋存形态及其转化过程

以在江淮地区典型经济欠发达村镇(忠庙)构建的化粪池-土地处理系统为对象,研究了土地处理系统表层土壤中磷赋存形态及其转化过程。结果表明,土地处理系统表层土壤中TP含量在149.2～159.4 mg/kg之间,且在运行实验后其含量有所增加。在磷赋存形态方面,Ca-P占TP含量的百分比最高,达到33.1%,随后依次为Ex-P、Org-P、Fe-P和Oc-P,分别为26.1%、19.6%、14.2%和7.0%;在磷活性方面,活性磷(Ex-P和Fe-P)占TP含量的百分比较大,在运行实验后由38.0%增至40.3%,可能是由于惰性磷(Oc-P、Ca-P和Org-P)转化所致,而Org-P矿化速率大于其累积速率。相关性分析表明,除Ca-P外,其他各形态磷均与土壤pH不相关,而Org-P与OM、TP、Ex-P和Ca-P均呈正相关。

Partitioning and transformation of phosphorus in surface soil of land treatment system

As a typical economically underdeveloped town in Yangtze-Huaihe region, Zhongmiao was selected to study phosphorous (P) partitioning and transformation in the surface soil of land treatment system. The results showed that total P (TP) contents in the surface soil were between 149.2~159.4 mg/kg, and increased after running test. Of all the forms of P evaluated in this study, Ca-P was present at the highest level and accounted for 33.1% of the TP, followed in order by Ex-P, Org-P, Fe-P and Oc-P, which accounted for 26.1%, 19.6%, 14.2% and 7.0% of TP, respectively. Bio-available P (Ex-P and Fe-P) accounted larger percentage of TP, and increased from 38.0% to 40.3% after running test, which may be due to inert P (Oc-P, Ca-P and Org-P) transformation. In addition, the mineralization rate of Org-P was greater than its cumulative rate. The correlation analysis showed that different P forms were irrelevant with pH (except Ca-P), but Org-P was found to be positively correlated with OM, TP, Ex-P and Ca-P.