中国农田氮肥面源污染估算方法及其实证:Ⅲ估算模型的实证

Estimation and Demonstration of Nitrogen Non-point Pollution in China:Ⅲ Demonstration of the Model

在总结农田氮肥淋失的一般性规律基础上,建立了农田氮肥淋失的理论模型,具体建立了以下4类模型并进行了实证:施肥量与地下水硝态氮含量关系模型(直接评价模型)、施肥量与土壤硝态氮淋失量关系模型(间接评价模型)、施肥量与土壤硝态氮淋失浓度关系模型(间接模型)、施肥量与土壤硝态氮残留量关系理论模型(间接评价模型)。研究表明:上述4个理论模型和实际模型的比较说明,虽然氮的淋失总体上与施氮量正相关,但是不同气候区和土壤条件,其开始淋失或积累的施肥量不同,并且随施肥量增加的趋势(快慢)也不同,因此,必须建立适合于不同区域的模型参数才能实现更准确的淋失预测。但是,从宏观上,也可以通过参数的平均而大体地预测氮的淋失等级或趋势。

Based on the summarization of the rule of nitrogen leaching loss, a theory model of nitrogen leaching loss was built. The models ineluded the relationships between the fertilization rate with groundwater nitrate, soil nitrate leaching loss, soil nitrate leaching loss concentration and soil nitrate residues. The results showed that there was a positive correlation between nitrogen leaching loss and fertilization rate, but the fertilization rate leading to leaching loss and accumulation of nitrogen varied with different climate and soil conditions, and the rate of nitrogen leaching loss was also different with different fertilization rates. So, determination of the model parameters fitting to different areas was necessary for forecasting nitrogen leaching loss. The average parameters can be used to forecast the grade and rate of nitrogen leaching loss.