Effects of Different Tillage Methods on Weed Emergence in Summer Soybean Field

The effects of conventional tillage and conservation tillage on the weed emergence in summer soybean field were studied.The results showed that the weed occurrence had significant differences with the conventional tillage(CT),conventional tillage with straw(CTS),no-tillage(NT),and no-tillage with straw(NTS).With the four tillage methods,the weed emergence rate was 260.80 seedlings per m2,133.87 seedlings per m2,319.56 seedlings per m2 and 41.78 seedlings per m2 7 weeks after sowing,respectively,and the weed biomass was 1567.33 g/m2,397.93 g/m2,1 842.17 g/m2 and 369.00 g/m2 8 weeks after sowing,respectively.Straw mulching was the decisive factor affected the weed emergence rate.About 95% weeds emerged in 3 weeks after sowing in the summer soybean field,which was the suitable time to control weed.