太湖流域农村地区典型村镇土壤养分和水体污染现状调查

为了了解和评价当前太湖流域农村地区典型村镇土壤养分和水体污染现状,本文以宜兴市周铁镇和万石镇农村地区为研究区域,分别采集土壤样品60个,水体样品79个,分析其土壤中氮磷的含量以及水体中化学需氧量和氮磷的含量。结果表明:宜兴市农村地区菜地和果园土壤中氮和磷含量过高,养分流失风险最大;其次为麦地土壤;而林地土壤样品中氮和磷含量较低,养分流失风险最小。当地农户在设施蔬菜大棚、果园和麦地中施用大量化肥是导致菜地、果园和麦地土壤氮、磷累积的主要原因。采集的水体样品中,地表河流水、养殖废水和田间沟渠水的污染物浓度变化较大。其中地表河流水的化学需氧量、铵态氮、总氮和总磷的平均含量分别为57、1.7、3.8、0.27 mg/L。55个地表河流水样品中有10个处于V类水的标准,其余45个样品均为劣V类。

Investigation Status of Soil Fertility and Water Pollution in Representative Villages of Taihu Lake Watershed Rural Area

In order to evaluate the soil fertility and non-point source water pollution status in representative villages of Taihu Lake watersheds rural area, 60 soil samples and 79 water samples were collected from rural area of Zhoutie and Wanshi towns, Yixing City. The nitrogen and phosphorous content of soil and water and Chemical Oxygen Demand (CODcr) of water were measured. The results demonstrated the concentrations of available nitrogen and phosphorus in vegetable fields and orchards were high, followed with wheat field, which all led to high risk of N and P loss in this area. The concentrations of available nitrogen and phosphorus in woodland were low, which led to low risk of N and P loss. Excess fertilizer application in greenhouse vegetable field, orchards and wheat field was the main reason for high fertility content in these fields. The concentrations of contaminants in river, breeding wastewater and ditch water varied significantly. The average concentrations of CODcr, ammonium nitrogen, total nitrogen and total phosphorous in river were 57, 1.7, 3.8 and 0.27 mg/L respectively. Only 10 samples in 55 samples of river water were in V level, the others were below V level.