论文部分内容阅读
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。
Field experiments were conducted to study the effects of different nitrogen levels (0, 150, 200, 250, 300 and 400 kg / hm ~ 2) on nitrogen uptake, mineral nitrogen balance and corn yield in spring maize plants. The results showed that the mineral nitrogen in soil decreased with the increase of soil depth. Nitrate accumulation peaked at 20-40 cm and 100-120 cm respectively. In 0-40 cm soil depth, N0 and N150 treatments were lower than other treatments. When the nitrogen application rate was <264.16 kg / hm ~ 2, the nitrogen uptake by maize plants was positively correlated with the nitrogen application rate. When the nitrogen application rate was more than or equal to 264.6 kg / hm ~ 2, (p <0.01). The apparent N losses of 0-120 cm soil were positively correlated with N application rate. When N application rate was <221.36 kg / hm ~ 2, N supply was insufficient. Under the experimental conditions, the threshold of chemical nitrogen fertilizer application was 221.36-264.16 kg / hm ~ 2, and the highest nitrogen application rate was 252.93 kg / hm ~ 2.