Rice-wheat Rotation Soil Nitrate Residue Analysis

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.