Detailed Explanation of Key Points in Artificial Cultivation Techniques of Sophora flavescens
Growth Habits
It mostly grows on hillside grasslands, plains, hills and riverbanks. It has no strict requirements for soil, and can grow well in all types of soil. Its root system is well developed, its water requirements are not high, and its light requirements are not strict either; the intensity of light has little effect on its growth, but plants grown in moist, fertile, deep soil with strong natural fertility are tall and sturdy.
The plant is more than 150 cm tall, with many branches on the upper part. The main root is thick and cylindrical, with a bitter taste. The petals are yellow or yellowish-white. The pods are cylindrical, and the seeds are brownish-yellow or brownish; they do not split open after maturity. The flowering period is June to July, and the fruit ripening period is September to October. The withering period is early October, with an annual growth period of 150 to 160 days. The 1000-seed weight is about 50 grams; the storage life under natural conditions is 3 years; the suitable germination temperature is 15 to 30 degrees C. The germination rate of untreated seeds is not high; at 30 degrees C for 5 days, the germination rate is only 20%. In production, seeds must undergo mechanical treatment before sowing.
Sowing Methods
1. Site selection and land preparation: Sophora flavescens is a deep-rooted plant. It is best to choose sandy loam and clay loam with deep, fertile soil and good drainage. Apply compound fertilizer, plow 20—25 cm deep, break up the soil and level it, and make beds 1.5 m wide.
2. Sowing Time
Both spring sowing and autumn sowing are acceptable. After autumn sowing, mulching is needed; otherwise the soil surface tends to crust, which is unfavorable for seedling emergence in spring. Autumn sowing should be early rather than late; sowing can be done as soon as the seeds mature, and it must be completed before the soil freezes. Spring sowing should be done around Qingming, when the soil moisture is relatively good, which is favorable for seedling emergence.
3. Sowing: drilling or hole sowing. From the perspective of field management, hole sowing is better. Seedling raising and transplanting are also used, but transplanting is rather troublesome. First rake the bed surface repeatedly, then dig holes at a row spacing of 40-50 cm and a plant spacing of 30 cm, with a hole depth of about 3 cm, sow 6 to 8 seeds per hole, cover flat, and press lightly. The sowing rate is 2 kg per mu. For drilling, the row spacing is 30 cm and the plant spacing is 20 cm, with 4 kg of seeds used per mu.
Field Management
Under normal conditions, seedlings emerge about 7 days after sowing. Because weeds grow quickly, they should be removed in time, and the soil should be loosened appropriately. In early May, root topdressing is carried out, mainly with nitrogen fertilizer, to promote the early vegetative growth of the seedlings; in early May, another topdressing is carried out, mainly with phosphorus and potassium, to strengthen rejuvenation, promote the accumulation of nutrients in the roots, and promote the differentiation of overwintering buds; in mid-to-late August, soil is hilled up once to promote the formation and protection of overwintering buds. Cultivate 4 to 5 times. In northern regions, drought easily occurs in spring, so irrigation should be carried out in time to ensure the normal growth of the seedlings. Because the seed coat does not easily absorb water, untreated seeds and seeds covered too deeply during sowing may show the phenomenon of emergence in the second or even the third year.
In the same year, the plant height can reach about 60-70 cm, and it basically does not flower. After the plants wither in autumn, clean up the dead branches and cover with decomposed livestock manure, first to protect the overwintering buds, and second to serve as topdressing for the growth of the next year.
Before harvesting, repeat the management work of the previous year every year, and at the same time remove the inflorescences for topping, to ensure the accumulation of nutrients in the roots, so as to obtain Chinese medicinal materials with high yield and good quality.
Harvesting and Processing
Sophora flavescens is used medicinally for its roots. After 2 to 3 years of cultivation, dig them up in spring or autumn, with autumn harvesting being better. After digging out the roots, remove the root heads and fibrous roots, wash off the sand and mud, and dry in the sun. Fresh roots are sliced and dried in the sun, and are called Sophora flavescens slices.