Eng . ) 1 . kinds and characteristics of different chemistry and organic fertilizers ; 2 . conversion in the soil of various kinds of fertilizer elements ; 3 . principle and practice on the fertilizer is used rationally 中) 1 .各种化学与有机质肥料的种类及其特性; 2 .各种肥料元素在土壤中的转换; 3 .肥料合理施用(适时、适地、适作、适法及适量施用肥料)的原理与实务。