Effects of Different Nitrogen Management Strategies on Soil Inorganic Nitrogen Leaching in Wheat-Maize Rotation System

Using winter wheat variety Shixin 616 and summer corn variety Jundan 20 as the materials,the effects of different nitrogen management strategies on inorganic nitrogen leaching in 0-100 cm soil layer were studied by field experiments and in situ leaching device in winter wheat-summer maize rotation system of piedmont high yield farmland of Hebei Province.The results showed that NO3--N leaching and accumulation of different nitrogen fertilizer treatments were increased with the increaseing of nitrogen fertilization in 0-100 cm soil layer.The order of influences of different nitrogen fertilizer treatments on the distribution and cumulative amount of inorganic nitrogen in 0-100 cm soil layer was OPT+N treatmentFP treatmentFP-S treatmentOPT treatmentOPT-N treatmentCK.The yields of wheat and maize were increased significantly and the inorganic nitrogen accumulations of soil after wheat and maize harvest were decreased significantly in the OPT treatment.The nitrate nitrogen mainly existed in 20-40 cm soil layer during wheat season,while in maize season it was appeared mainly in the surface and deep layer.Excessive nitrogen fertilization was the main source of soil nitrogen leaching and accumulation.Considering the economic and ecological benefits,the OPT fertilization strategy was worth to be recommended to farmers in the straw mulching condition.