Effect of Nitrogen Applied Levels on Nitrogen Uptake, Biomass Accumulation and Yield in Hybrid Cotton Plant

A field experiment was carrried out to study the effect of nitrogen applied levels on biomass accumulation,nitrogen uptake and yield in hybrid cotton plant under drip irrigation condition with one facter randomized block and five levels of nitrogen application(0,135,270,405,540 kg.hm-2).The result showed that the biomass,nitrogen content and yield of hybrid cotton were increased with nitrogen application increasing,they reached their highest value at 405 kg.hm-2 nitrogen applied level,and were increased by 49.93%,75.43% and 82.24%.The effect of nitrogen application on biomass accumulation and nitrogen uptake in buds,flowers and bolls was more than it in stems and leaves.The biomass accumulation and nitrogen uptake speed,boll number and weight were increased significantly through increasing nitrogen application.Hybrid cotton could obtain high yield at 270 kg.hm-2 nitrogen applied level in this experiment.But,if nitrogen application was too much,yield would not be increased any more.In this study,the suitable nitrogen application rate which hybrid cotton reached the highest yield was at 386.5～388.4 kg.hm-2.