What are the field management measures for Coptis chinensis cultivation?

1. Replanting: In the first 3 years after planting, replanting should be done promptly. Generally, replanting is done 2 times: the 1st time in the autumn of the same year, and the 2nd time after the snow melts the following year but before new leaves emerge.

2. Weeding: In the year of planting and the following year, weed promptly and loosen the surface soil, weeding 4-5 times each year; chemical herbicides can also be used to kill weeds, with 150-300 g of 50% prometryn or 200-300 g of 25% diuron, or 125 g of 10% nitrofen per mu, with obvious results. For Coptis chinensis transplanted for 3-4 years, weed 3-4 times each year, and once in the 5th year. In the 3rd-5th years, weeding should be combined with loosening the soil.

3. Topdressing and earthing up: 2-3 days after planting, irrigate the seedlings with dilute pig manure water or decomposed rapeseed cake water; fine chopped compost or barnyard manure at about 1000 kg per mu can also be broadcast. In September-October of the same year, after seed harvesting in the 2nd-5th years, and in September-October of the 2nd-4th years, apply fertilizer 1 time each, for a total of 8 times. For spring topdressing, use 1000 kg of human manure water per mu or 50-100 kg of decomposed rapeseed cake (add 1000 kg of water); 10 kg of urea and 20-30 kg of calcium phosphate can also be mixed evenly with fine soil or fine compost and broadcast. Autumn topdressing is mainly farmyard manure, together with plant ash, oil cake and other fertilizers, broadcast on the bed surface about 1 cm thick, at 1500-2000 kg per mu. On the upper slopes and bed edges prone to rain erosion, apply appropriately more. For Coptis chinensis, after autumn topdressing in the 2nd-4th years, soil should also be earthed up by broadcasting fine humus soil on the bed surface. In the 2nd-3rd years, earth up about 1 cm thick. In the 4th year, 1.5 cm. For Coptis deltoidea, in the 2nd and 3rd years, weed and fertilize 1 time each in spring, using 100 kg of oil cake and 2.5 kg of urea per mu mixed evenly with 600 kg of fine humus soil, broadcast on the bed surface and covered with earth. Except for no earthing up in the year of planting and 1 earthing up in spring of the harvest year, earthing up should be done in all other years in spring and winter in addition to weeding and loosening the soil. The thickness is about 3 cm. For Coptis teeta, topdress 1 time each in early summer and late autumn every year. In high-altitude areas, apply 5000 kg of forest humus soil per mu, mixed with 250 kg of plant ash, and broadcast on the bed surface. In low-altitude areas and areas near villages, apply 1000-1500 kg of farmyard manure per mu.

4. Removal of flower stems: Except for plants retained for seed, promptly remove flower stems from the 2nd year onward.

5. Shade shed management: In the year of planting, the shade density is 80-85%. From the 2nd year, the shade density decreases year by year, reduced to 40-50% in the 4th year. After harvesting seeds in the 5th year, remove the shed cover to increase light. For Coptis chinensis planted in forests, the shade density is relatively high in the 1st-2nd years after planting. From the 3rd year, attention should be paid to thinning branches, with a shade density of about 50%. Every winter and spring, cut off tree roots around the trunks at a depth of 20-30 cm. For Coptis deltoidea, at the time of Frost's Descent each year, after applying winter soil, lower the shed frame (longitudinal poles and crossbars) and the covering material on it together, laying them flat on the bed surface in order to cover the Coptis chinensis plants. After the snow melts and the soil thaws in spring, promptly rebuild the frame. The method and requirements for rebuilding the frame are the same as for building the shed.