棉 花 学 报 Cotton Science 2006，18(6)：323-326
Research on Dynamic Increase Characteristics of Dry Matter of Cotton at Different Nitrogen Levels Abstract：Field experiments were conducted to quantitatively analyse the dynamic accumulation characteristic of biomass of cotton under different nitrogen levels(0kg、120kg、240kg、360kg、480kg 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 Hai 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.
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