Different density and fertilizer ratio can affect yield of spring wheat qreatly,our study draw the following conclusions:(1)in the range from 3,750,000 hm -2 to 6,000,000 hm -2 ,the yield of spring wheat did not change significantly,so we can properly decrease the density of Long Fu 91-B569.

Application of mixture experiment design in studying the effects of fertilizer combination;

Approach of relative subjects on establishment and improvement of China s framework of technical criterion of fertilizer evaluation;