A Study on the Formula for Polybasic Compound Fertilizer of Powdered Coal Ash Applied in Rice

The result of the study indicates that applying polybasic compound fertilizer of powdered coal ash increases the content of nutrients in soil, meets the need of rice for various nutritional elements, enhances the growth and development of rice, and increases rice production and economic performance. The yields from the treatments with different formulae are higher by 1% on average than that of the control making remarkable difference. According to the field experiment, the formule of 3∶1∶4 and 3∶1∶2 are optimum, which increase the yields of early and late rice by 13.3%, 10.6% and 10.4%, 9.8% respectively compared with that of the cotrol.