Detailed Explanation of Pollution-Free High-Yield Cultivation Techniques for Vegetable Soybean

I. Site Selection and Bed Preparation

Choose sandy loam soil with convenient drainage and irrigation, deep soil layer, good permeability, high organic matter content, and a pH value of 6.5 for planting. When preparing the beds, first plow and sun-bleach the soil, then carry out fine bed preparation, with beds and furrows together 80-85 cm wide and bed height 25-30 cm. Paddy-upland rotation fields are preferable; avoid continuous cropping with legumes.

??II. Timely Sowing and Reasonable Close Planting

Spring: Sow when the temperature stabilizes at 1°C; in western Fujian, this is from late March to mid-April.

Autumn: Mid-to-late July is more suitable. Carefully select seeds, choosing plump seeds from the previous year's autumn propagation that have no cracked skins and no disease spots. Sun the seeds for 1-2 days before sowing, and cover promptly with farmyard manure or sandy soil after sowing.

Reasonable close planting: Use a row spacing of 25-35 cm, plant spacing of 23-25 cm, about 15,000 plants per mu, with a seeding rate of about 5 kg per mu, sowing 2 seeds per hole.

III. Scientific Fertilization

In conjunction with bed preparation, apply 67 kg of farmyard manure plus 15 kg of calcium magnesium phosphate per mu as base fertilizer. For the first topdressing within one week after emergence, mix 15 kg of compound fertilizer or 15 kg of ammonium bicarbonate and 15 kg of superphosphate evenly, dilute with 750 kg of water, and pour along the middle of the bed. For the second topdressing at the branching stage, in conjunction with hilling, apply 20 kg of ternary compound fertilizer or 20 kg of ammonium bicarbonate and 15 kg of superphosphate mixed evenly per mu, dilute with 800 kg of water, and apply along the middle of the bed. Generally no topdressing is applied after flowering; if the plants are small and cannot close the rows, apply a light topdressing of 4.5 kg of urea per mu.

IV. Water Management

Vegetable soybean is sensitive and needs water but is intolerant of waterlogging. Generally, lower soil moisture should be maintained during the seedling stage. From the flower bud differentiation stage to the flowering and pod-setting stage, shallow and frequent irrigation should be used to keep the soil moist but not dry. After entering the seed-filling stage, alternating wet and dry conditions are suitable to prevent premature senescence.

??V. Timely Harvest

Generally, when the pods have filled more than 80% and the pod shells appear emerald green, this is the best time to harvest fresh green pods; at this time the beans are tender, have good flavor, and excellent appearance quality. For autumn-sown seed production, harvest immediately when 80% of the pods in the field turn brown, then spread them out to dry to promote after-ripening and increase the rate of intact seeds.