Effects of Nitrogen,Phosphorus and Potassium at Different Proportion on Biological Traits and Yield of Cotton

The orthogonal test of nitrogen,phosphorus and potassium at different proportion applyed to cotton was carried out and the results showed that under the experimental conditions,nitrogen was the primary factor on the biological traits and yield per plant or per hectare.The second factor was potassium followed by phosphorus.Nitrogen fertilizer could be used at a higher rate,and phosphorus and potassium at a medium rate.The cotton showed optimum biological traits and the highest yield when nitrogen,phosphorus and potassium fertilizers were used at the rate of 300 kg,37.5 kg and 300 kg per hectare respectively.If considering the production cost,the ideal application rates of nitrogen,phosphorus and potassium fertilizers were 300 kg,75 kg and 150 kg per hectare,respectively.