Key Technical Points for High-Yield Cultivation and Management of Bean Sprouts in Greenhouses

Bean sprouts, also known as sprouting vegetables, are edible "sprouts" cultivated from the seeds of various grains, legumes, and trees, also called "living vegetables." Common sprouting vegetables include: Chinese toon sprouts, buckwheat sprouts, alfalfa sprouts, Sichuan pepper sprouts, green black bean sprouts, jequirity bean sprouts, sunflower seed sprouts, radish sprouts, dragon whisker bean sprouts, peanut sprouts, broad bean sprouts, and more than 30 other varieties. With rich variety and comprehensive nutrition, they are a common vegetable.

Medicinal Value of Bean Sprouts

Japanese scientists have found that during the germination of mung beans, some proteins can break down into amino acids, thereby increasing the original amino acid content. They also contain cellulose; if stir-fried or served cold with Chinese chives, they are both safe and effective for constipation in the elderly and young children. Consuming mung bean sprouts can treat night blindness caused by vitamin A deficiency, tongue sores, stomatitis and scrotal inflammation caused by vitamin B2 deficiency, and scurvy caused by vitamin C deficiency. When cooking mung bean sprouts, it is best to add a little vinegar, which helps the protein coagulate quickly, keeping the sprouts firm and attractive while preserving nutrients; at the same time, stir-fry quickly over high heat to avoid excessive destruction of vitamin C.

Nutritional Value of Bean Sprouts

1. Bean sprouts are rich in vitamin C and can treat scurvy;

2. They also help remove cholesterol and fat deposits from blood vessel walls and prevent cardiovascular disease;

3. Mung bean sprouts also contain riboflavin, making them very suitable for people with mouth ulcers;

4. They are also rich in dietary fiber, making them a healthy vegetable for constipation sufferers, with the effect of preventing digestive tract cancers (esophageal cancer, stomach cancer, rectal cancer);

5. Bean sprouts are very low in calories while high in water and cellulose content; eating them regularly can help achieve weight loss goals.

High-Yield Cultivation and Management Techniques for Bean Sprouts in Greenhouses

Greenhouse Construction

The greenhouse should be built in a location with sufficient sunlight, flat terrain, shelter from wind and facing the sun, and good water source conditions. Generally, a harp-string type or single-slope plastic greenhouse is used. The greenhouse height is 2.0-2.5 m, width about 7 m, with an area of about 300 sq m being suitable.

Cultivation Bed Preparation

Cultivation beds should be made into small north-south oriented beds about 1.2 m wide and about 6.0 m long, with bed ridges 20.0 cm wide, compacted as much as possible. The bed surface should be dug down 4.0-6.0 cm, leveled and tamped firm; if conditions permit, it can be hardened. Leave a 40-60 cm wide walkway along the back wall for transporting materials during production.

Variety Selection

For greenhouse bean sprout production, small-seeded summer-sown beans are best; this variety sprouts quickly, has fewer diseases, good quality, strong adaptability, and high yield, with an input-output ratio of about 1:10-12. Next is small-seeded summer-sown soybean; this variety grows faster and also sells well, but the input-output ratio is about 1:6-8, it tends to age, has more fiber than red beans, and the taste is average.

Seed Treatment

After selecting the variety, remove broken seeds and impurities, and prepare seeds at 2 kg/sq m based on the usable bed area. Then soak in warm water at 40 degrees C at 1.2-2.0 times the volume, while adding 2 mL of rootless sprout hormone per 10 kg of bean seeds; once the seeds have absorbed enough water, they can be sown.

Sowing

Before sowing, first spread a 3 cm thick layer of nutrient soil on the prepared bed surface, level it and rake it fine; do not tamp it firm, to maintain soil permeability and nitrogen content, and keep soil moisture at about 50%. Evenly scatter the treated seeds on the bed surface, then cover the seeds with a 2 cm thick layer of fine sand; the sand should be at the same temperature as the nutrient soil. After gently raking level, cover with plastic film or woven bags.

Scientific Management

When about 70% of the seeds have sprouted white, carry out one heavy watering, about 5-6 buckets per bed; afterward water once daily, and according to weather conditions maintain the greenhouse temperature at 25-30 degrees C. When the seed hypocotyls extend to 1.5-2.0 cm, promptly remove the sand on top; if the sand is too loose, lightly sprinkle a little water. After the sand removal work is complete, water heavily once more to wash the remaining covering sand into the bed, exposing all the bean sprouts, but do not let sunlight shine on the bean cotyledons; if necessary, cover the small beds in the greenhouse with colored film or other coverings. Thirty minutes after watering, spray rootless bean sprout hormone and bean sprout thickening agent; afterward water on schedule every day, observe growth at all times, and according to conditions appropriately spray rootless bean sprout hormone or sprout thickening agent, one vial per bed each time, and this can be combined with the application of a stress-resistance yield-increasing agent.

Harvesting and Precautions

Harvest when plant height is 10-12 cm, the two cotyledons are neither fully open nor closed, the sprout segments are uniform, the sprout stems are moderate, and the color is bright. When harvesting, carefully pull them out, tie into 0.5 kg small bundles, remove seed coats and impurities as much as possible, and maintain a good appearance.

Precautions:

(1) For each production cycle, remove the soil and sand used in the previous cycle and replace with new soil and new sand; when necessary, disinfect the bed surface with lime water or benzalkonium bromide.

(2) Use chemicals reasonably. Generally, when temperatures are high and cotyledons develop quickly, apply more rootless bean sprout hormone and less bean sprout thickening agent, with the spray concentration controlled at 800-1000 times; conversely, apply less rootless sprout hormone and more bean sprout thickening agent, with the spray concentration controlled at 500-800 times.

(3) The water used each time must be clean and hygienic; strictly prohibit the use of water with oil stains or contamination.

(4) No light is needed during the growth period, to avoid affecting quality. If producing green bean sprouts, allow short-term light exposure before harvest to enhance color and greenness while maintaining a crisp and tender quality.