不同施氮水平下棉花生物量动态增长特征研究

Research on Dynamic Increase Characteristics of Dry Matter of Cotton at Different Nitrogen Levels

在大田实验条件下,以定量方法系统地分析了黄淮海棉区(以河南安阳为试点)不同施氮水平(每公顷0 kg、120 kg、240 kg3、60 kg、480 kg)下棉株生物量的动态累积特征,结果表明:棉株地上、地下部分干物重的动态累积符合Logistic生长曲线,生物量的增长对氮肥施用量较为敏感;施肥量为360 kg.hm-2时棉田具有快速增长期启动早、持续时间短、增长速率大等特征,说明该施氮量利于棉花生长前期的生物量的快速累积,氮肥施用量过多或过少均不利于合理棉花群体的建立;不同的施氮量可以调节快速生长期的早晚和持续时间,同时亦可改变其干物质累积速率。生产中可以通过调节氮肥的施用量与时间获得高产。对于黄淮海棉区,适宜的施肥量为360 kg.hm-2,7月中旬为棉田肥水管理的关键期。

Field experiments were conducted to quantitatively analyse the dynamic accumulation char acteristic of biomass of cotton under different nitrogen levels（0 kg.120 kg.240 kg,360 kg,480 kg per hectare ） in Anyang, Henan Province. The result indicated that, dynamic accumulation model of dry matter of above-ground, under-ground, and it＇s potions of cotton could be described by Logistic equation. The accumulation of drymatter was sensitive to nitrogen level. Earlier stage of speediness growth, shorter period and bigger increase rate were the characteristic at 360 kg·hm^2 nitrogen level. It is shown that nitrogen rate could accelerate the accumulation of biomass in earlier growth stage. Excess or deficiency nitrogen was a disadvantage for establishment of rational colony. The nitrogen rate and its application time are important for highest yield to be obtained. In the climate region of Huai River and Hal River reaches （Anyang, Henan Province）,the optimal nitrogen application rate was 360 kg·hm^2 ,and the important period of nitrogen management was the time of the middle ten days of July .