不同供氮水平对春玉米干物质积累及氮素吸收利用的影响

为了掌握玉米适宜施氮量，研究不同供氮水平对春玉米干物质积累和氮素吸收利用的影响。本研究采用田间小区试验的方法，设置0、120、240、360 kg/hm² 4个施氮水平，研究了玉米各器官干物质吸收积累、氮素吸收利用及产量的变化。结果表明，不同供氮水平下春玉米干物质积累和氮素吸收均符合Logistic方程y=K/(1+ae^bx)]，氮肥施用量可明显影响干物质最大积累速率和氮素最大吸收速率，各施氮水平下均表现为N₃₆₀＞N₂₄₀＞N₁₂₀＞N₀。玉米产量随施氮量的增加而增加，施氮量为360 kg/hm²时，玉米产量最高，达10081.5 kg/hm²，但相较N₂₄₀玉米增产效果并不显著，同时氮肥利用率较N₂₄₀降低15.5%。本试验条件下，综合考虑产量和氮素利用效率两因素，施氮量240 kg/hm²为玉米最佳氮肥用量。

Effects of Different Nitrogen Application Rates on Dry Matter Accumulation, Nitrogen Absorption and Utilization of Spring Maize

In order to study the suitable nitrogen application and the influence of dry matter accumulation and N absorption under different N applicatio different N application rates （N 0 kg/hm2, n levels on 120 kg/hm2, spring maize, field experiment was conducted under 240 kg/hm2 and 360 kg/hm2）. The results showed that both the dynamic dry matter accumulation and N absorption of spring maize could be described by Logistic equation. N application rates could significantly influence both the maximum rates of dry matter accumulation and N absorption, and the order of different N application rates was N360〉N240〉N120〉N0. The results also showed that maize yield increased with the increment of nitrogen application rate. When the nitrogen application rate was 360 kg/hm2, the maize yield reached the highest 10081.5 kg/hm^2, but it had no significant difference with N240 and the nitrogen utilization efficiency was 15.5% lower than that of N240. Considering the maize yield and nitrogen utilization efficiency under the experimental conditions, N application rate of 240 kg/hm2 was identified to be the optimum amount.