Detailed Explanation of Bai Zhi (Angelica dahurica) Planting Methods and Key Technical Points
How should Bai Zhi (Angelica dahurica) be planted? What should be noted? Please provide guidance. Bai Zhi prefers warm and humid conditions with ample sunlight, fears high temperatures, can tolerate cold, and has strong adaptability. Bai Zhi has no strict requirements for the previous crop; even continuous cropping land where the previous Bai Zhi crop grew well can be used. It is best to choose flat terrain with ample sunlight, deep tillage layer...
How should Bai Zhi (Angelica dahurica) be planted? What should be noted? Please provide guidance
Bai Zhi prefers warm and humid conditions with ample sunlight, fears high temperatures, can tolerate cold, and has strong adaptability.
Bai Zhi has no strict requirements for the previous crop; even continuous cropping land where the previous Bai Zhi crop grew well can be used. It is best to choose flat terrain with ample sunlight, a deep tillage layer, loose and fertile soil, and well-drained sandy loam.
After the previous crop is harvested, apply 2500-5000 kg of decomposed compost or barnyard manure, 100 kg of cake fertilizer, and 50 kg of phosphate fertilizer per mu as base fertilizer. Fertile land can use less. After application, plow to a depth of more than 1 chi (approximately 33 cm). After plowing, sun-dry the soil to allow full weathering, then plow again. Because Bai Zhi roots grow relatively deep, when preparing the land, deep plowing and fine harrowing are necessary, and the fertility of the upper and lower soil layers should be uniform to prevent excessive fibrous roots caused by overly fertile topsoil, which affects yield and quality. After leveling and harrowing, make beds 15-20 cm high and 1-2 m wide. The bed surface should be flat to facilitate irrigation and drainage, and the topsoil should be level and fine to help seedlings emerge.
Propagation Methods of Bai Zhi
Seed propagation is used, generally by direct sowing. Transplanting is not suitable, as transplanted plants develop forked roots and poor main root growth, affecting yield and quality.
1. Sowing Period
In production, there are strict requirements for the sowing period. Sowing at the right time is one of the important steps for obtaining high yields. Sowing too early causes seedlings to grow too vigorously before winter, and some plants will bolt and flower prematurely the following year, with roots becoming lignified or rotting, making them unusable for medicinal purposes and thus affecting yield. Sowing too late causes temperatures to drop, affecting germination and seedling emergence; seedlings are prone to frost damage, grow poorly, and yields are low. Because seeds stored for more than a year have a low germination rate while fresh seeds have a high germination rate, fresh seeds harvested in the current year must be selected for sowing in production. Generally, autumn sowing is the main method; spring sowing results in low yield and poor quality. The suitable sowing period varies with climate and soil fertility. When temperatures are high, sow later; when temperatures are low, sow earlier. Fertile soil allows slightly later sowing; conversely, sow slightly earlier.
The suitable sowing period for autumn sowing varies by location.
2. Sowing Methods
Drilling, dibbling, and broadcasting are all acceptable, but drilling is generally most common.
Drilling method: space rows 25-30 cm apart, open shallow furrows (about 4-5 fen or approximately 1.3-1.7 cm deep), sow seeds evenly into the furrows, and cover with a thin layer of fine soil. Generally, use 1-1.5 kg of seed per mu.
Field Management of Bai Zhi
1. Thinning and Final Spacing
Bai Zhi seedlings grow slowly. Generally, no thinning is done in the sowing year. After the seedlings turn green in early spring of the second year, when seedlings are about 5-7 cm tall, carry out the first thinning, removing overcrowded and weak seedlings. For drilling, leave one plant about every 5 cm; for dibbling, leave 5-8 plants per hole. For the second thinning, leave one plant about every 10 cm or 3-5 plants per hole. Around Qingming, when seedlings are about 15 cm tall, final spacing is done: space plants 13-15 cm apart or leave 3 plants per hole in a staggered triangular arrangement to facilitate ventilation and light penetration. During final spacing, remove large seedlings with overly vigorous growth and greenish-white leaf stalks to prevent premature bolting and flowering.
2. Cultivation and Weeding
This should be done together with thinning and final spacing. Once the leaves gradually grow larger and the bed surface is closed by the canopy, weeding is no longer necessary.
3. Topdressing
Bai Zhi is tolerant of fertilizer, but generally little or no fertilizer is applied before spring to prevent overly vigorous seedling growth and premature bolting and flowering. After spring, when vegetative growth becomes vigorous, topdressing can be done 3-4 times. The 1st and 2nd applications are both done after thinning and cultivation; the 3rd and 4th are done after final spacing and before canopy closure. Fertilization should be done on sunny days; it is not suitable to fertilize on the day when rain has just cleared or immediately after cultivation and weeding. Fertilizer types can include human feces and urine, decomposed cake fertilizer, pen manure, urea, etc. For the first fertilization, the fertilizer should be thin and small in amount, such as applying 10 dan of dilute human and animal manure per mu; afterward, it can gradually be made thicker and more concentrated, such as 30-40 dan. The application before canopy closure can include phosphorus and potassium fertilizer, such as 20-25 kg of superphosphate, to promote thick and strong roots. It has been reported that applying 25 kg of calcium magnesium phosphate fertilizer and 5 kg of potassium chloride in the topdressing before canopy closure, followed immediately by earthing up, can prevent lodging and promote growth.
The number of topdressings and the amount applied each time can also be determined according to plant growth. If, when canopy closure is approaching, the leaves are light green and growth is not very vigorous, one more topdressing can be applied; or if the leaves are dark green and growth is vigorous at this time, no more topdressing is needed.
4. Irrigation and Drainage
Bai Zhi likes water but fears waterlogging. After sowing, if the soil is dry, water immediately. Afterward, if there is no rainy weather, water every few days to keep the bed surface moist before seedling emergence, which helps emergence. During the seedling stage, soil moisture should also be maintained to prevent yellow leaves and the formation of too many lateral roots. Before seedlings overwinter, water thoroughly once. Henan has the experience that "wet freezing is best; dry freezing makes survival difficult," and Hebei has the experience that "in winter, Bai Zhi only dies from drying, not from freezing." After spring of the following year, timely irrigation can be combined with topdressing, especially during the dog days when sufficient moisture should be maintained. If the rainy season brings waterlogging in the field, open ditches promptly to drain water to prevent root rot and disease occurrence from standing water.
5. Removal of Bolting Plants
In May of the second year after sowing, some plants will bolt and flower. Their roots cannot be used medicinally, and the seeds they produce cannot be used as seed because the next generation will bolt prematurely. Therefore, to reduce nutrient consumption in the field, bolting plants should be removed promptly when found.
Click to get more Bai Zhi planting techniques
Click to get more medicinal herb planting techniques