滇池流域大棚土壤硝酸盐累积特征及其对环境的影响

对滇池流域主要大棚土壤的分析结果表明：随着大棚年限的增长，土壤剖面(0～60 cm)土层中硝态氮在不断累积，加重了土壤次生盐渍化；大棚内0～20 cm、20～40 cm土壤硝态氮含量与全盐的相关性均达极显著水平。同时对大棚区的地下水、地表水的分析结果表明：地下水中NO^-₃含量与土壤NO^-₃含量呈正相关，相关系数为0.945^**，大棚种植区土壤的NO^-₃累积严重威胁地下水环境；地表水中的总氮含量与大棚土壤NO^-₃含量的相关性很好(r=0.994^**)，大棚种植区土壤的NO^-₃累积将加重滇池面源污染的负荷。

Characteristics of nitrate accumulation in the greenhouse soil of Dianchi basin and its effect on the environment

The nitrate concentrations in greenhouse soil and the water of Dianchi basin were investigated.Results show that NO~-_3-N concentration in 0~60 cm soil layers increased with the increasing of the age of plastic greenhouse,aggravating soil salinization.There is a significant positive relationship between NO~-_3-N content and total salt concentration in greenhouse soil,the correlation(coefficient) of the soil lay(0~20 cm) is 0.899~(**),the soil lay(20~40 cm) is 0.676~(**).There is a positive relationship between the(NO~-_3-N) concentration in ground water and the NO~-_3-N concentration in greenhouse soils(0~20 cm),the correlation coefficient was 0.945~(**),nitrate accumulation in soil has seriously threat to ground water in Dian-lake drainage area.There is a positive relationship between the total N concentration in surface water and the NO~-_3-N concentration in greenhouse soils(0~20 cm),the correlation coefficient is 0.994~(**).The accumulation of soil nitrate will aggravate the burthen of non-point source pollution in Dianchi basin.