Abstract:

In order to explore the optimal sowing date and density of the new soybean variety ‘Luodou 1304’ bred by Luoyang Academy of Agriculture and Forestry Sciences, a split plot experimental design was adopted. The main plot was sowing period B (B₁: June 21, B₂: July 1, B₃: July 11), and the sub plot was density M (M₁: 135000 plants/hm², M₂: 180000 plants/hm², M₃: 225000 plants/hm², M₄: 270000 plants/hm²). The effects of sowing period and density on the growth process, photosynthetic characteristics, agronomic traits, yield, and quality of ‘Luodou 1304’were analyzed. The results showed that delaying the sowing date would shorten the growth process of ‘Luodou 1304’. For every 10 days of sowing delay, the growth period would be shortened by 4 days and 5 days, respectively. Early sowing at the appropriate time could significantly increase the net photosynthetic rate and transpiration rate during the peak flowering and pod period, and reduced the intercellular CO₂ concentration during the peak flowering period; significantly reduced the height of the bottom pod and increased the weight of one hundred seeds; significantly increased crude protein content and total egg fat content. Reducing density would significantly increase the net photosynthetic rate during the peak pod period and significantly reduced the intercellular CO₂ concentration during the peak pod period; significantly increased effective branching per plant, effective pod number per plant, grain number per plant, and grain weight per plant. The sowing date had a significant impact on yield, with early sowing yielding more than late sowing. The average yield of B₁ sowing date was the highest, reaching 5269.49 kg/hm², significantly higher than that of B₂ and B₃ sowing dates. The effect of density on yield was relatively small. Under the B₁ sowing period, there was no significant difference in yield between different densities, and the yields under M₂, M₃, and M₄ densities were relatively high, reaching 5249.45 kg/hm², 5219.68 kg/hm², and 5683.21 kg/hm², respectively. This study found that planting density had a smaller effect on yield than sowing date. The most suitable sowing date for ‘Luodou 1304’ is June 21st, with a suitable density of 180000 to 270000 plants/hm². The study aims to provide theoretical and technical support for the demonstration and promotion of the new variety ‘Luodou 1304’.

Key words: sowing time, density, ‘Luodou 1304’, yield, quality