Effects of Planting Density on Yield and Quality of Multiple Cropping Soybean After Wheat

In order to explore the technical system of multiple cropping when following wheat with early-maturing soybean in the first accumulated temperature area of Heilongjiang Province, to improve land use efficiency and farmers’ income, the experiment of multiple cropping of Wancang 5 was carried out, the growth and development of soybean were investigated with different planting densities of 540 000,615 000 and 705 000 plants·hm^-2; Protein and fat contents of soybean grains and the main yield traits were determined.The results showed that the effects of different densities on plant height, branch number and pod number were not significant, but the effects on node number of main stem was significant.The protein and fat contents of soybean grains were different between different planting densities, but not significant.The planting density of Wancang 5 was more than 615 000 plants·hm^-2,and the yield could reach more than 1 500 kg·hm^-2.In 2020,three demonstration test sites of Longfumai 1 multiple-cropping early-maturing soybean Wancang 5 were set up in Daqing city, and considerable economic benefits were obtained.