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

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

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/hm24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+aebx)],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240kg/hm2为玉米最佳氮肥用量。

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.