Environmental effect on yield and quality of high protein soybean

In the orthogonal experiment of four factors including density,fertilizer level,variety and sowing date,the leaf area index(LAI) and the Leaf area duration(LAD) increased with higher density and fertilizer level and late sowing date.The chlorophyll content increased with higher fertilizer level and later sowing date.The main factors that affected yield were sowing date and fertilizer.The yield was high when the sowing date was late.The high-protein soybean quantity was primarily genetic determined,and it could be modified by fertilizer levels.In this research,Nongda 35307 had the highest LAI,chlorophyll content and LAD.There was no significant yield difference among four vatiaties.Nongda 3191 and Nongda 35307 had higher protein content.Nongda 35318 reached its highest yield of 5 572.14 kg/hm2 with the density of 29.85×104 plants/hm2,the fertilizer level of 74.63kg/hm2 and sowing on May 11th;while Nongda 3191 reached its highest protein content at 29.85×104plants/hm2,without fertilizer and sowing on May 6th.It indicated that quality was mainly genetically determined,and could be further affected at certain level by the environment.However,yield could be affected by the environment.