Detailed Explanation of Key Points for Spring Sowing Cultivation Techniques of Isatis Root

Currently, the Chinese medicinal herb Isatis root is well regarded in the market. The spring sowing season for Isatis root is approaching, so how is Isatis root cultivated in spring? 1. Land selection and preparation. Isatis root is a deep-rooted plant, with a main root that can reach 40-50 cm in length, so fertile sandy soil with deep soil layers and good drainage should be selected for planting. Before sowing, plow the land deeply 20-30 cm; sandy land can be plowed slightly shallower. Apply sufficient base fertilizer, mainly farmyard manure, then break up the clods and rake level to make beds. In the south, high beds are mainly used to facilitate drainage. Generally, the bed width is 1.5-2 m and the height is about 20 cm. 2. Sowing. Isatis root should be sown in March to April. When sowing, first draw shallow furrows about 2 cm deep on the bed surface at a row spacing of 20-25 cm, then evenly scatter the seeds into the furrows, cover with about 1 cm of soil, press lightly, and water appropriately in dry conditions. When the temperature is suitable, seedlings can emerge 7-10 days after sowing. The seeding rate per mu is 1.5-2 kg. 3. Field management. When the seedlings are 7-10 cm tall, thin them in time in combination with cultivating and weeding, and finally set the plants at a spacing of 6-8 cm. After setting the plants, according to the plant growth condition, appropriately apply one additional application of human excrement and urine or chemical fertilizer. In plain areas with abundant water or in rainy seasons, deep ditches should be added around the field to facilitate timely drainage and avoid root rot. If hot and dry weather occurs during the dog days, water in the early morning and evening, and be sure not to water under direct sunlight. 4. Harvesting and processing. For spring-sown Isatis root, the leaves can be harvested 2-3 times. The first time is in mid-June, when the seedlings are 20 cm tall, leaving stubble of 2-3 cm to encourage new leaf growth; the second time is in late August. It is not suitable to harvest during the hot dog days to avoid causing death of large patches. The harvested leaves are sun-dried and become the medicinal Daqingye. Those with large leaves, few broken pieces, cleanliness, dark green color, and no musty smell are best. Isatis root should be dug before the onset of winter on a sunny day. When digging, be sure to dig deep to prevent breaking the roots. After lifting from the soil, remove all soil, stems, and leaves, spread out to dry until 70-80 percent dry, tie into small bundles, then sun-dry further and they can be taken to the market to sell.