Effects of Sowing Time and Seeding Rate on Yield and Quality of Chinese Milk Vetch in Fujian

  Objective   To determine the appropriate time and seeding rate for sowing seeds of Chinese milk vetch (Astragalus sinicus L.) in the rice producing areas in Fujian.

  Method  Four dates, i.e, September 30, October 25, November 20, and December 15, were selected to sow the Chinese milkvetch seeds at a rate of 15.0, 22.5 or 30.0 kg·hm⁻² in the rice field. From the 12 varied treatments, growth and yield as well as the content and cumulation of nutrients of the plants at flowering stage were monitored.

  Result  As the sowing time pushed toward end of a year, the plant height, stem girth, branch count, and nutrient accumulation of the Chinese milk vetch declined, while the nitrogen, phosphorus, and potassium contents increased at first, then decreased. The amount of seeds used in sowing did not result in a significant difference on yield. Overall, higher yields and nutrients accumulation in the hay were observed when the plants were sowed before December 15. They peaked at a seeding rate of 22.5 kg·hm⁻² on September 30 with a hay yield of 6.94 t·hm⁻² and accumulated nitrogen of 144.01 kg·hm⁻², phosphorus of 14.45 kg·hm⁻², and potassium of 116.01 kg·hm⁻².

  Conclusion  The seeding at a rate of 22.5 kg·hm⁻² on September 30 appeared to be most desirable for obtaining high yield and quality of the hay in Fujian. It was found ineffective to compensate the production reduction due to late sowing by increasing the seeding amount.