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.