施氮量对小麦/玉米带田土壤水分及硝态氮的影响

Abstract

The purpose of the study was to analyze the dynamic impacts of vary amount of N-fertilization(0、210、420and 630 kg /hm2) on the soil water content and NO-3-N content from the field of wheat-corn intercrop field.The data showed that the total kernel yield of intercropping wheat and maize increased with the increase of nitrogen supply,it could reach as high as 13661—14668 kg /hm2 when 420 kg /hm2 of N-fertilizer applied.When the nitrogen supply is 420 kg/hm2,the water use efficiency of the filed can reach 21.25 kg · hm-2 · mm-1.After wheat was harvested,the soil water content in the layer of 0—120cm depth decreased with the increased amount of nitrogen supply,while the content of nitrate nitrogen increased with the increased amount of nitrogen supply.Moreover,the soil nitrate nitrogen content of the topsoil(0—60cm) was significantly higher than that of the soil layer at the depth of 60—200cm.The dynamic changes of soil nitrate content during the whole growth season of intercropped wheat and maize could be summarized into a double-peaked curve.When the 0 and 210 kg/hm2 nitrogen supply were applied,the first and second peaks appeared at the wheat trefoil stage and the maize large bell stage,respectively.However,the first peak appeared at the wheat flagging stage when 420 and 630 kg /hm2 nitrogen supply applied;and the second peak appeared at the maize large bell stage and the grain-filling stage when 420 and 630 kg/hm2 nitrogen supply applied,respectively.Therefore,the results suggested that the high-yield nitrogen supply was 420 kg/hm2 for the wheat and maize intercropping cultivation mode,With this amount of nitrogen supply,the accumulation and transformation of the soil nitrate nitrogen could be reduced,and therefore fulfill the purpose of the efficiency and environmental safety.