Abstract:

The key meteorological factors affecting soybean growth and yield were studied to provide reference for soybean production in northwest Liaoning. Using soybean varieties ‘Tiefeng 18’, ‘Tiefeng 29’ and ‘Tiefeng 31’ as materials, the response of soybean growth and yield to heat condition was studied. The results showed that the lower limit sowing temperature of soybean was 8.0℃, and the optimum sowing temperature was 15-20℃, and the yield was the most prominent with sowing in the middle and late May. The accumulated temperature of ≥ 10℃ should be more than 1140.0℃·d in the emergence-flowering stage of soybean, more than 1210.0℃·d in the flowering-maturity stage, and more than 2580℃·d in the whole growth period of soybean. The relationship between accumulated temperature and yield is parabolic function, and the accumulated temperature ≥10℃ between 2800℃ and 3060℃·d is the caloric index of soybean high yield. There are three key temperature periods for soybeans, namely, the rapid growth period of soybean flowering in early to mid-June, the flowering and binding period of soybean in mid to late July, and the granulation period in mid to late August. The temperature in early to mid-June affected the yield by 33.7 kg/(hm2·℃), the temperature in mid-to-late July affected the yield by -17.5 kg/(hm2·℃), and the temperature in mid-to-late August affected the yield by 10.6 kg/(hm2·℃). When the moisture condition is satisfied, the change of temperature is the determining factor for soybean yield and composition. The results of the experiment play a positive guiding role in developing soybean industry to cope with climate change in northwest Liaoning Province.

Key words: soybean, sowing by stages, heat, yield, northwest of Liaoning