【摘要】 通过田间试验,研究不同氮素水平(0、150、200、250、300、400 kg/hm~2)对春玉米植株地上部分吸氮量、农田矿质氮平衡和玉米产量的影响。结果表明,土壤中矿质氮随土层深度的增加逐渐降低,硝态氮在20~40 cm和100~120cm各有1个积累峰值。在0~40 cm土层深度内,N0和N150处理铵态氮含量低于其他处理。当施氮量<264.16 kg/hm~2时,玉米植株吸氮量与施氮量呈正相关;当施氮量≥264.16 kg/hm~2时,施氮量对玉米植株吸氮量增加不显著(p<0.01)。0~120cm土壤氮素表观损失量和施氮量呈正相关,当施氮量<221.36 kg/hm~2时,氮肥供应不足。本试验条件下,化学氮肥施用阈值为221.36~264.16 kg/hm~2,最高产量施氮量为252.93 kg/hm~2。更多还原

【Abstract】 The field experiment was conducted to investigate effects of nitrogen application on spring maize inyield, crop nitrogen uptake and mineral nitrogen（N min） balance, that designed to 6 levels of nitrogen applicationrates（0, 150, 200, 250, 300 and 400 kg/ha）. The results showed that, N min content with increasing soil depth wasgradually reduced, which ammonium nitrogen（NH₄⁺-N） and nitrate nitrogen（NO^3--N） had two peaks in the soil depthof 20-40 cm and 100-120 cm, respectively. N0 and N150 treatment NH₄⁺-N content was lower than the others onthe soil depth of 0-40 cm. There was positive correlation between the crop nitrogen uptake and nitrogen fertilizer ap-plication < 264.16 kg/ha（p<0.01）, there was not significant while N application ≥ 264.16 kg/ha. There was positivecorrelation between the apparent nitrogen loss and N application in the soil depth of 0- 120 cm, namely, nitrogenfertilizer was short supply in field when N application < 221.36 kg/ha. In conclusion, a reasonable nitrogen applica-tion rate should be about 221.36-264.16 kg/ha, nitrogen application rate of the highest yield was 252.93 kg/ha.更多还原