稻麦轮作条件下土壤硝态氮残留分析

Rice-wheat Rotation Soil Nitrate Residue Analysis

土壤中硝态氮残留浪费了氮肥资源,加大了农业生产的资金投入,同时给地下和地表水环境带来威胁,硝态氮在土壤剖面中的含量及其空间分布特征是表征硝态氮淋失风险的重要指标。选取苏州市甪直镇淞浦村稻麦轮作土壤为试验土壤,取水稻一个生命周期为试验时间,设置氮肥施加浓度梯度,分层对土壤取样进行测定。结果表明,土壤各个耕层中硝态氮的含量在施加氮肥后都有一定程度的改变,其中不施氮肥的氮素残留减少,其他施氮肥组氮素残留均较施肥之前有所增加;土壤硝态氮主要累积在30cm和150cm以下;施氮肥量越大,土壤硝态氮在0～180cm土层范围内的累积量也越大。

Nitrate nitrogen residual wastes resources ,increases investment in agricultural production ,while threaten the underground and surface waters environment at the same time. Content and distribution of nitrate nitrogen in the soil profile is the characterization of nitrate leaching risk of important indicators. Taking the rice-wheat rotation soil in Luzhi Town of Suzhou as test soil,the rice lifecycle for the test of time,the nitrogen concentration gradient was set,and the soil samps were tested. The results showed that all plow layer of nitrate nitrogen concentration was imposed upon a certain level of change in soil, the residual nitrogen of non-nitrogen treatment reduced ,while other nitrogen groups increased than before. The main soil nitrate accumulated in 30 cm and 150 cm or less ;and the nitrate nitrogen in 0-180 cm soil also had cumulative quantity with the increase of nitrogen amout.