Effects of Different Planting Time on Agronomic Characters,Yield and Seed Quality of Two Spring Soybean Varieties

There are large soybean planting area in Guangxi province. In order to find out the best planting time in spring and seed reproduction time in summer and autumn,two soybean varieties named GC8 and HC2,planted widely in Guangxi,were used to research effects of the different planting time on growth stage,agronomic characters,yield and seed quality in 2011.21 planting times were arranged in this experiment. The results showed that the highest yield of the planting time was in Feb. 25 th,2,770. 85 and 2,666. 26 kg·ha- 1,respectively. And the yield of the autumn planting time was the lowest,followed by the summer planting time. From the beginning of spring planting time to Jun 25 th,both of the time that emerging to flowering and maturing was shortened,when the planting time was postponed. After July 5th,days that emerging to flowering and maturing changed a little. When the two soybean varieties were planted before early of Mar. and after early of Aug. protein content of seeds from both of the two varieties was lower relatively,but oil content was higher oppositely. Protein content of soybean seeds planted after the middle of March was higher than that of summer and autumn. In conclusion,considered the yield,the best plating time of the spring soybean was from middle of Feb. to early of Mar. in middle and south of Guangxi province. Reproduction had better arranged as early as possible in summer. Considered the quality of the soybean seed,planting before early of Mar. can get higher oil content seeds.