Effect of NPK Fertilization and Recommendation for Single Cropping Rice in Hilly Regions in Central Fujian

For single cropping rice cultivation in the hilly regions of central Fujian, 15 field experiments based on a "3414" design on NPK fertilization were conducted. The results showed that the yield was strongly affected by the existing soil fertility, with a significant linear correlation between the fertilizer applied and the resulting rice output. The average yield by Treatment 6, which had a balanced fertilization at the rate of 8 397 kg·hm^-2, showed the average yield increases of 16.2%, 6.5%, and 8.3%, by the N, P, and K applications, respectively. Its net revenue reached 21, 663 yuan·hm^-2, with the increases of 14.4%, 4.5%, and 6.3% due to N, P, and K fertilizations, respectively. The results from the experiments on the high-, moderate-and low-yield fields were subject to regression analysis and modeling. It appeared that the average application rates of N, P₂O₅ and K₂O at 219, 95 and 154 kg·hm^-2, in the proportion of 1:0.43:0.70, would be appropriate for a single cropping rice in the hilly areas. Nonetheless, since significant differences on the fertilization effect were found in fields of varied fertilities, optimization for specific site would be needed. In other words, in practice, fertilization must take the existing soil fertility into consideration in order to reach the target production objectives.