Responses of Vegetable Soybean Yield to the Application of Potassium Fertilizer

The effects of four potassium fertilizer rates with additional foliar application on fresh pod marketable yield and seed number at maturity in vegetable soybean were investigated under normal N and P fertilizers by pot experiment.Though responses were different between cultivars,potassium application at seeding significantly increases the marketable yield and seed number at maturity.Maximum yield components are all obtained at 120 kg·hm^-2 K rate except standard pod number per plant in CAS Edamame No.1.Compared with control,the fresh pod weight,fresh seed weight,and seed number per plant of CAS Edamame No.1 at 120 kg·hm^-2 K rate,are increased by 31.5%,16.2% and 34.0% respectively;while line No.121 are increased by 34.2%,50.5%,and 32.4% respectively.At 120 kg·hm^-2 K rate,additional foliar application of potassium at flowering and pod-setting stages increases the fresh pod weight,fresh seed weight,and seed number per plant by 8.8%,48.5% and 5.8% in CAS Edamame No.1,and by 3.5%,28.0% and 3.6% in line No.121 respectively.K application has no effect on standard pod number but significantly increases seed number and seed weight.Maximum marketable yield could be realized at 120 kg·hm^-2 K₂SO₄ with additional foliar application of 30 kg·hm^-2 of K₂SO₄.