广西武鸣河流域非点源氮磷污染特征及源解析

Characteristics and source apportionment of nitrogen and phosphorus non-point source pollution in Wuming River Basin,Guangxi

分析了广西武鸣河流域不同种植作物的土壤氮磷形态特点,并使用主成分分析对河流水体和沉积物中的氮磷进行了源解析.不同种植作物土壤统计和单因素方差分析结果表明,流域周边农田土壤总氮(TN)和总磷(TP)含量范围分别为802.60~2740.42和109.01~784.59mg/kg.种植玉米土壤氨氮(NH_(4)^(+)-N)和硝酸盐氮(NO_(3)^(-)-N)显著高于其他土壤(P<0.05);甘蔗土壤NO_(3)^(-)-N显著高于其他土壤(P<0.05);种植柑橘土壤交换态磷(Ex-P)和铁/铝态结合磷(Fe/Al-P)显著高于其他土壤(P<0.05).主成分分析结果表明,武鸣河水体中TN可能主要来源于种植玉米和甘蔗土壤的养分流失.沉积物中Fe/Al-P、钙结合磷(Ca-P)和NH_(4)^(+)-N可能分别主要来源于柑橘、桉树和玉米土壤.种植玉米和甘蔗土壤的氮流失可能造成了武鸣河最主要的非点源污染问题,说明土地作物类型是影响流域非点源污染的重要因素.

This paper analyzed the characteristics of soil nitrogen and phosphorus forms of different crops in the Wuming River Basin in Guangxi,and used principal component analysis to analyze the source of nitrogen and phosphorus in river water and sediments.The results of soil statistics and one-way analysis of variance for different crops showed that the total nitrogen(TN)and total phosphorus(TP)contents of the farmland around the watershed ranged from 802.60 to 2740.42mg/kg and 109.01 to 784.59mg/kg,respectively.The ammonium nitrogen(NH_(4)^(+)-N)and nitrate nitrogen(NO_(3)^(-)-N)of corn planting soil were significantly higher than other soils(P<0.05);The NO_(3)^(-)-N of sugarcane soil was significantly higher than other soils(P<0.05);Citrus planting soil Exchanged phosphorus(Ex-P)and iron/aluminum combined phosphorus(Fe/Al-P)were significantly higher than other soils(P<0.05).The results of principal component analysis indicated that TN in Wuming river may mainly originate from nutrient loss of soil planted with corn and sugarcane.Fe/Al-P,Ca-P and NH_(4)^(+)-N in the sediments may mainly originate from citrus,eucalyptus and corn soils,respectively.From the above analysis,it is known that the nitrogen loss of the soil for planting corn and sugarcane may have caused the most important non-point source pollution problem in Wuming River,indicating that the type of land crop is an important factor affecting non-point source pollution in the watershed.