武汉市郊典型利用方式下土壤磷素特征及流失风险分析

当前地表水体环境问题日益突出,磷素作为水体富营养化的关键控制因子而备受关注。本研究通过实地采样分析,研究了武汉市郊区典型利用方式下土壤磷素形态剂含量特征,并分析了其流失风险。结果表明:不同利用方式下的土壤磷素水平差异较大,各形态磷水平排序是蔬菜地稻田常规旱地苗圃地;武汉城郊0～20cm表层土壤全磷(TP)含量为255.4～1763.1mg/kg,平均值为975.4mg/kg;土壤有效磷(Olsen-P)为1.3～164.2mg/kg,平均值为56.4mg/kg;藻类有效磷(NaOH-P)含量为33.4～910.7mg/kg,平均值为204.0mg/kg;土壤Olsen-P为56.0mg/kg可作为武汉市郊区土壤磷素流失的临界值,且超过该临界值的土样有34.9%,其中有93.3%采自蔬菜地,表明各利用方式下蔬菜地土壤磷素流失风险最高。

Phosphorus Characteristics and Loss Risk Assessment under Typical Land Utilization in the Suburbs of Wuhan

Phosphorus (P) as the restricting factor that leads to water eutrophication is always given to attention with the surface waters environmental problem getting obvious in China. Based on the field survey the soil phosphorus contents in the suburbs of Wuhan, the soil phosphorus characteristics under different land utilizations were studied and the loss risk was analyzed. Results showed that there was significant difference in the content of soil phosphorus under different land utilizations. As to various lands use type, the order of different soil phosphorus content is as vegetable soil＞ paddy field＞ the other dry lands＞ nursery. In the upper soil layer of 0～20cm under different land use type, the content of total phosphorus was 255.4～1763.1mg/kg, and the mean was 975.4mg/kg. The content of Olsen-P was 1.3～164.2mg/kg, and the mean was 56.4mg/kg and the content of NaOH-P was 33.4～910.Trng/kg, and the mean was 204.1mg/kg. The content of Olsen-P was 56.0mg/kg was critical value that could be used to evaluate the loss risk of soil phosphorus. There were 34.9% in all soil samples that exceeded 56.0mg/kg and 93.3% of them were vegetable soil.