Detailed Explanation of Key Cultivation and Planting Techniques for Atractylodes macrocephala
Atractylodes macrocephala is a perennial herb, 30-60 cm tall, flowering from September to October, fruiting from October to November. It prefers a cool climate, fears high temperatures, and is relatively cold-tolerant. High temperatures are unfavorable for the growth of Atractylodes macrocephala and can easily trigger diseases such as damping-off and southern blight, causing the rhizome to rot and the plant to die. Atractylodes macrocephala fears both drought and waterlogging, and sandy loam soil with good drainage is most suitable. Continuous cropping is avoided, and it cannot be rotated with peanuts, cabbage, tomatoes, radishes, potatoes, tea, or with Xuanshen (Scrophularia ningpoensis), Shengdi (Rehmannia glutinosa), Baishao (Paeonia lactiflora), Chuanxinlian (Andrographis paniculata), Fuzi (Aconitum carmichaelii), etc. The previous crop is best a grass-family crop. However, newly reclaimed wasteland can also be used to grow Atractylodes macrocephala.
I. Cultivation Methods
1. Seed Selection and Seedling Raising
(1) Seed selection: To distinguish genuine from fake seeds, note that fresh Atractylodes macrocephala seeds are reddish with fine hairs, have a glossy surface, a clear cross-section, and a pinkish line at the embryo in the center.
(2) Seedling raising and seed soaking: Soak the seeds first in warm water at 25-30°C for one day and night. Seedling raising can be done in either spring or autumn; raise seedlings in the first year and transplant in the next year. Spring sowing is from late March to early-to-mid April, and sowing is best when the ground temperature is above 12°C. On a seedbed leveled and raked fine, open furrows horizontally for drilling, with row spacing of 15-20 cm, sowing width of 7-10 cm, and furrow depth of 3-5 cm; the furrow bottom should be level. Soak the selected and treated seeds in a 1000-fold solution of 50% thiophanate-methyl for 3-5 minutes to prevent rust leaf disease. Mix the air-dried seeds evenly with sand, scatter them into the furrows, tread them slightly firm with the foot, cover with plant ash just until the seeds are no longer visible, then spread a layer of superphosphate or cake fertilizer, cover with a thin layer of soil, and optionally cover with a layer of dry grass to keep warm and moist so as to help the seeds emerge; remove it gradually after emergence. The seeding rate is 5-8 kg per mu, and 1 mu of seedlings can transplant 7 mu of field. If dibbling, use row spacing of 20 cm, plant spacing of 10 cm, hole depth of 3-5 cm, with 3 seeds per hole; seedlings can emerge in about 7 days.
(3) Seedling stage management: After the seedlings emerge fully, carry out intertillage and weeding so that there are no weeds in the field and the soil does not become compacted. When the seedlings are 7 cm tall, thin them to a plant spacing of 3-5 cm. Young seedlings fear both waterlogging and drought, so drainage and irrigation must be timely. Apply the first topdressing when there are 2-3 true leaves; apply the second topdressing in early July during the underground rhizome enlargement stage, using 500-800 kg of manure water per mu; in the later growth stage, remove flower buds as early as possible to promote rhizome growth.
2. Seedling Storage Methods: To overwinter safely, the seedlings must be dug up and stored. In the sowing year, from early-to-mid October to early November, choose a sunny day when the soil is dry and dig up the seedlings, shake off the soil, remove diseased, weak, and damaged seedlings, spread them in a ventilated place to dry in the shade, and store them only after the outer skin turns white, so as to prevent mildew and rot.
(1) Jar and crock storage: A small number of seedlings can be stored in jars or crocks over winter. Insert a bundle of rice straw in the middle of the container for ventilation and heat dissipation, first lay a layer of green pine leaves on the bottom and along the four walls, then put in the Atractylodes macrocephala seedlings, and cover the top with green pine leaves or dry moss; after the green pine leaves turn yellow and dry, replace them promptly to maintain sufficient moisture.
(2) Sand storage method: This method can be used when the quantity is large. Indoors in a cool, ventilated place, first build a square enclosure with bricks or stones, then spread fine sand 3-4 cm thick on the earthen floor, and stack the seedlings in layers, that is, one layer of seedlings and one layer of sand, inserting one straw bundle every 0.6-1 m. When the pile reaches 35 cm high, cover it with 7 cm of sand or soil to seal the top, and place fir branches on top to prevent rodent damage. When winter temperatures are relatively low, add another layer of rice straw. The sand and soil must be moderately dry and wet; turn and inspect the pile once every 15-30 days, and promptly remove diseased seedlings.
(3) Overwintering in place: Atractylodes macrocephala seedlings from autumn sowing can be covered with dry grass or film and overwintered in place. In the following spring, dig and plant them as needed.
3. Field Cultivation Techniques
(1) Select good seed stock: Select rhizomes with plump apical buds, well-developed root systems, tender epidermis, slender tops, and large round tails as seed stock, classify them by size, and plant them separately, which can make the seedlings uniform, facilitate management, and increase yield.
(2) Planting time: The transplanting period should be determined according to local climate, soil, and cropping system. It begins in late December and continues to early April of the following year. Early planting is preferable; those planted early first develop roots and then grow buds, have well-developed root systems, grow vigorously, are more cold-tolerant and drought-resistant, and have higher yields. Those planted too late, because temperatures rise, first grow buds and then grow roots, have poor root development, and lower yields.
(3) Planting methods: There are hole planting and row planting. Planting density depends on soil fertility and fertilizer conditions. Proper close planting can increase yield. The basic stand is 8000-15000 plants per mu, using 40-60 kg of seedlings, planted in holes at row spacing of 23-26 cm and plant spacing of 13-16 cm, with hole depth of 7 cm. First apply human manure and urine, and after it dries place the seedlings in the holes with the buds facing upward and the fibrous roots spread out, then cover with soil to bury them, with the apical bud 3.5 cm from the soil surface. If buried too shallow, they are prone to cold damage, produce many buds, and have poor rhizome shape; conversely, if buried too deep, they sprout slowly, have difficulty emerging, and produce slender rhizomes of poorer quality.
II. Field Management Techniques
1. Intertillage and weeding: After Atractylodes macrocephala emerges, weed frequently and loosen the soil shallowly to keep the field free of weeds. After the plants close the rows in mid-May, only weed and do not intertill. Do not weed when the morning dew has not dried, otherwise diseases are easily contracted.
2. Topdressing: Atractylodes macrocephala has a long growth period of 220-240 days. In addition to applying sufficient base fertilizer before planting, topdressing should also be applied 3 times. The first time is in early April, during the period of vigorous growth of the aboveground parts, with 800 kg of manure water per mu; the second time is in late May, with 500 kg of manure water per mu; the third time is from mid-August to late September, with 2000 kg of manure water and 100 kg of cake fertilizer per mu. In addition, within more than 40 days before harvesting Atractylodes macrocephala, spraying a 1% superphosphate solution as foliar fertilizer can increase yield; spray once every 10 days, for a total of 2-3 sprays. In short, the principle of "apply sufficient base fertilizer, apply seedling fertilizer early, and apply bud fertilizer heavily" should be mastered.
3. Drainage and irrigation: Atractylodes macrocephala fears waterlogging; excessive soil moisture makes it prone to disease. From April to June in the rainy season, clear the field furrows promptly to drain water and prevent waterlogging. After August, the rhizome expands rapidly. Sufficient water is needed, and in case of drought, water promptly to ensure water supply.
4. Bud removal: Removing flower buds reduces nutrient consumption and promotes the concentration of nutrients in the roots. Atractylodes macrocephala buds from early-to-mid July to early August, and when the buds have not yet opened, remove them completely in 3-4 batches. The action should be gentle, holding the stem with one hand and picking the buds with the other. Do not pick on rainy days or when the dew has not dried, to prevent disease invasion. For seed production, choose robust plants with large leaves and few branches, keep 5-6 large, well-developed buds at the top, and remove the rest. In early November, when the basal leaves of the plants wither and yellow and the pappus within the flowers becomes visible, harvest the whole plant, remove the rhizome for medicinal use, tie the rest into small bundles, place them in a ventilated, shaded place to dry in the shade, take them down after 1 month to thresh, winnow out impurities, dry in the sun for 1-2 days, and store in a ventilated, dry place.