9Fagenia N K, Baligar V C. Response of common bean, upland rice, com, wheat and soybean to soil fertility of an oxisol[J]. Plant Nutr. , 1997,20 : 1279 -1289.
10Bangar A R. Fertilization of sorghum based on modified mitscherlich-bray equation under semi-arid tropics [ J ]. Indian Soc. Soil Sci. , 1998,46 ( 3 ) : 383 -391.