重庆市主要土壤类型硝态氮淋失及其影响因素

采用SRC(Soil-Resin-Core)装置,研究了重庆市主要土壤类型硝态氮淋失的差异以及硝态氮淋失与硝态氮含量、有效氮含量、降雨和气温等4个方面的关系。结果表明:酸性紫色土的硝态氮淋失量最大,而黄壤与碱性紫色土的硝态氮淋失量较小。酸性紫色土硝态氮含量、有效氮含量与硝态氮淋失量之间显著相关,而黄壤和碱性紫色土的硝态氮含量、有效氮含量与硝态氮淋失量之间没有显著的相关性。降雨量、气温也是引起硝态氮淋失的原因。农田施肥对地下水的污染受施肥量、施肥次数、降雨量和气温等综合作用的影响,可采取控制氮肥用量,减少施用人粪尿,避免在降雨量大的时期追肥的措施。

Nitrate Nitrogen Leaching and its Affecting Factors under Main Soil Types of Chongqing

With soil-resin-core equipment, the difference of NO~-_3-N leaching in soil and its correlation with four aspects including the content of NO~-_3-N, the content of available N, rainfall and temperature were studied. The results were shown as follows: The NO~-_3-N leaching in acid purple soil was the highest, while it was lower in yellow soil and alkaline purple soil. Both the content of NO~-_3-N and available N were correlated positively with NO~-_3-N leaching in acid purple soil. The content of NO~-_3-N and available N were not interrelated with the NO~-_3-N leaching in yellow soil and alkaline purple soil. Rainfall and temperature were also primary factors which affected NO~-_3-N leaching. Fertilization rates, fertilization times, rainfall and temperature could result in together groundwater pollution. To control fertilizer rates, to reduce manure application and to avoid fertilizing in heavy rainfall were the effective ways to control nitrate nitrogen leaching.