Preliminary Study on the Effect of Planting Date on Soybean Growth and Yield Components

Experiments were carried out to study the effect of different planting date on soybean growth, dry-matter accumulation,leaf area dynamics and yield components in IV accumulated temperature zone of northern part of Heilongjiang province. The results showed that if we planted soybean later than normal planting date, the pods per plant, seeds per plant and 100-seeds weight would be lower than those planted normally because of shorter growth period If we planted soybean earlier than normal planting date, there would be less percentage of germination because of low temperature of soil. The pods per plant, seeds per plant and 100-seeds weiyht all lower than those planted normally From the results we could dran a conclusion that we should plant soybean around May 7 in this region, which would lead to average yield 11.8% higher than those planted earlier and 8.0% higher than those planted later.