Study on Effects of Fertilization on Tobacco in Hunan Province and the Optimal Economic Fertilization Model

The study collected the data of 30 3414 test points for flue-cured tobacco in Hunan province,conducted the path analysis,and built a function of fertilization effects of different fertilizer types.The results showed that the path coefficient of N fertilizer on tobacco yields was the largest(1.079 8),which was followed by that of P and K fertilizer.It indicated that N fertilizer had the largest contribution to the production of flue-cured tobacco.Interactive effects of N and P,N and P,as well as P and K were marked.Based on the analysis of 3regression models,we knew that optimal rates of N,P and K fertilizers were 164.7,145.4 and 352.6 kg/hm~2 respectively,the optimal ratio of N,P,K was 1:0.89:2.11,and the best yield was 2 194.7 kg/hm~2.The results provide a scientific basis for the balanced fertilization of flue-cured tobacco.