Detailed Explanation of Key Points for High-Yield Cultivation Techniques of Atractylodes macrocephala
Atractylodes macrocephalais a plant of the Asteraceae family, with its rhizome used as medicine, sliced raw or stir-fried. Atractylodes macrocephala prefers a cool climate and is afraid of high temperature and high humidity. It has no strict requirements for soil, preferring well-drained sandy loam, and is not suitable for planting in low-lying land or saline-alkali land.
Site Selection and Land Preparation
The previous crop for Atractylodes macrocephala is best to be a grass-family crop, or alternatively, virgin land or land where Atractylodes macrocephala has not been planted for more than 4 years may be chosen. Plow the soil 9-12 cm deep, level it, remove coarse stones, and make beds 75 cm wide for later use.
Sowing and Propagation
Sow in mid to late April. For drilling, use 4-5 kg of seed per mu; for broadcasting, use 5-7.5 kg of seed per mu. Before sowing, select plump seeds and mix with sandy soil before sowing into the field (in arid regions, it is advisable to first soak the seeds in warm water for 24 hours). For drilling, open shallow furrows 3-4.5 cm deep at a row spacing of 15 cm and a sowing width of 6-9 cm (the furrow bottom should be level to ensure uniform emergence). After sowing, cover with 3 cm of soil and press lightly so that the seeds and soil are firmly combined. Before emergence, the soil should maintain sufficient moisture; generally, 2-3 waterings will bring about emergence.
After the seedlings emerge, promptly weed and thin them out, removing crowded seedlings and diseased or weak ones. When the seedlings are 4.5-6 cm tall, thin to a plant spacing of 6-9 cm. Apply topdressing 1-2 times during the seedling stage, preferably with organic manure or urine, in modest amounts; in dry conditions, water appropriately or spread grass between rows to prevent drought.
From mid to late September to early November, begin digging up Atractylodes macrocephala planting stock, removing stems, leaves, and fibrous roots (taking care not to damage the main root or the epidermis of the rhizome), dry in the shade for 1-2 days, and store in a dry, cool place. First spread a 3 cm layer of sand, then a layer of planting stock (9-12 cm thick), then alternate layers of sand and Atractylodes macrocephala. When the pile reaches about 30 cm high, insert several bundles of grass in the center of the pile for ventilation, and cover with a layer of moderately moist sand or soil on top. In severe winter cold, cover with grass for insulation. During storage of the planting stock, check every 15-30 days, promptly removing diseased plants to prevent rot. If sprouting has not occurred, turn the pile to prevent bud growth.
Planting
Begin planting from late March to early April of the following year. Be careful to select planting stock that is robust, has well-developed roots, plump apical buds, tender epidermis, a slender top, and a large round base as propagation material; planting stock that is deformed, has lignified stem at the top, thick and long main roots, and few lateral roots will grow poorly after planting. Plant at a row-to-plant spacing of 24×12 cm or 18×12 cm, at a depth of 6-9 cm (with the planting stock buried and 3 cm of soil above), at a density of 10,000-12,000 plants per mu, using about 50 kg of planting stock per mu.
Intertillage and Weeding
Weed frequently and loosen the soil shallowly. In principle, achieve a field free of weeds and soil that is not compacted. Do not weed after rain when dew has not dried, otherwise diseases are easily contracted.
Rational Fertilization
In the cultivation of Atractylodes macrocephala, farmers have summarized the production experience of "applying sufficient basal fertilizer, applying green manure early, and applying heavy topdressing." Generally, basal fertilizer requires 500-1000 kg of organic fertilizer and 25-35 kg of superphosphate per mu; in early May when seedlings have basically all emerged, apply 1 application of dilute human manure or urine at 500 kg per mu; around the fruiting stage is the period when Atractylodes macrocephala has the strongest nutrient uptake, fastest growth and development, and most rapid rhizome expansion throughout its growth cycle. Generally, at full bloom, apply 1000 kg of organic fertilizer and 30 kg of compound phosphate fertilizer per mu.
Watering and Drainage
Atractylodes macrocephala prefers dry conditions, especially since high temperatures in the early stage can cause disease, and water accumulation in the field can easily kill seedlings. Pay attention to digging ditches, clearing ditches, and timely drainage after rain. In late August, rhizome expansion becomes pronounced and requires a certain amount of water. If there is a prolonged drought, water appropriately to keep the field moist, otherwise yield will be affected.
Removing Flower Buds
In order to concentrate nutrients for rhizome growth, except for seed-producing plants which retain 5-6 flower buds each, all others should be removed at the appropriate time. Generally, remove in 2-3 sessions from mid-July to early August. When removing buds, hold the stem with one hand and pick the bud with the other, keeping as many small leaves as possible and not shaking the plant roots. Bud removal should be done on sunny days; removing buds on rainy days allows wounds to be soaked with water and easily causes disease.
Processing of Atractylodes macrocephala
The product obtained by oven-drying is called "baked Atractylodes" or "kiln-dried Atractylodes," requiring 3 rounds of baking. In the first baking, the temperature is about 80°C; after 4-6 hours, turn the pieces over so that fine roots fall off; then bake at 60°C-70°C until 80% dry, remove and pile for 6-7 days so that internal moisture exudes and the outer skin softens, then dry at 50°C-60°C. When baking, the key is to control the heat according to the degree of dryness of the Atractylodes; one must prevent high-temperature rapid drying that causes puffing and scorching, and also avoid prolonged low-temperature baking that leads to oiliness, stuffiness, and mold.
Baked Atractylodes: hard in texture, darker in appearance (compared to sun-dried Atractylodes), with a slightly horn-like fracture surface, fissures, and a faint chrysanthemum pattern. Most commercial products from main producing areas such as Zhejiang and Hunan are processed as baked Atractylodes, which is the mainstream variety. The product obtained by sun-drying is sun-dried Atractylodes, achieved by repeatedly sun-drying fresh Atractylodes, but it takes a long time and must be protected from freezing. Because processing occurs in winter, it is also called winter Atractylodes. However, winter Atractylodes easily becomes oily and is not easy to preserve; some slice winter Atractylodes and apply mineral lime.
Sun-dried Atractylodes: relatively glutinous and soft in texture, with a cut surface that is off-white or yellowish-white. Dense without fissures, with a moist and lustrous appearance. This processing method is mostly applied in Anhui, Hunan, and eastern Zhejiang areas such as Yuyao, Ninghai, Xianju, and Fenghua.
Among the two commercial products, baked Atractylodes and sun-dried Atractylodes, baked Atractylodes is the mainstream processed variety because it is easy to preserve and not prone to becoming oily, but baked Atractylodes often has quality problems such as hollow centers and scorching due to poor control of the baking process. Although sun-dried Atractylodes is glutinous, dense, and oily-lustrous, it is prone to becoming oily due to hot and humid storage conditions, and therefore is not easy to preserve.