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在白洋淀周边农田进行田间试验,研究了不同施氮水平对夏玉米产量及氮肥利用率、土壤硝态氮累积量和土壤溶液硝态氮含量的影响。结果表明:夏玉米在施氮量为180 kg hm-2时达到最高产量,为9766 kg hm-2,不同氮肥水平的氮肥利用率在35.5%~46.2%之间,在120 kg hm-2时的利用效率最高,达到46.2%。土壤中硝态氮累积量在玉米整个生育时期呈现先下降后升高的趋势;过量施氮的Con N、Opt N+30%处理导致硝态氮在土壤中大量累积,夏玉米季整个种植期间Con N、Opt N+30%处理土壤溶液硝态氮始终处于较高浓度,提高了硝态氮淋溶风险。综合考虑产量和环境效益,在本试验条件下,白洋淀地区夏玉米的合理施氮量应控制在N 180 kg hm-2左右。
A field experiment was conducted in the farmland around Baiyangdian Lake to study the effects of N application rates on the yield and NUE of summer maize, soil nitrate accumulation and soil nitrate content. The results showed that the maximum yield of summer maize was 9766 kg hm-2 when the nitrogen application rate was 180 kg hm-2, and the nitrogen utilization efficiency was 35.5% -46.2% at different nitrogen rates. At 120 kg hm-2 The highest utilization efficiency, reaching 46.2%. Nitrate accumulation in soil tended to decrease and then increase in the whole growth period of maize. Con N and Opt N + 30% excess nitrogen application resulted in a large accumulation of nitrate nitrogen in the soil. During the whole summer maize season Con N, Opt N + 30% treatment of nitrate solution in soil solution is always at a higher concentration, increased nitrate leaching risk. Considering the yield and environmental benefits, under the test conditions, the rational nitrogen application rate of summer maize in Baiyangdian should be controlled at about 180 kg hm-2.