Detailed Explanation of Standardized Artificial Cultivation Techniques for Mugwort
Standardized Artificial Cultivation Techniques for Mugwort
Mugwort (Artemisia argyi) is a perennial herbaceous plant of the genus Artemisia in the Asteraceae family, also known as bingtai (from "Erya"), aihao, huangcao (from "Piya"), yicao (from "Bielu"), jiucao, etc., and has a long history of medicinal and edible dual-use applications in China [1]. Mugwort is mainly distributed in eastern Asia, such as most parts of China, the Korean Peninsula, Japan, Mongolia, and other places [2]. Modern research shows that mugwort contains polysaccharides [3], flavonoids [4-6], terpenoids [7-10], phenylpropanoids [11], steroids [12], fatty acids [13], and various other active components, with biological activities such as treating ulcers [6], promoting blood circulation [14], antioxidant [11, 15], anti-inflammatory [16], antibacterial [17], anti-cancer and immune regulation [18]. Ancient texts and traditional Chinese medicine classics record that the whole plant of mugwort used as medicine has effects such as warming meridians, removing dampness, dispelling cold, stopping bleeding, reducing inflammation, relieving asthma, and suppressing cough. Moreover, due to its long history of application, people have a high degree of acceptance of it, and its medicinal safety is relatively high. In recent years, the demand for mugwort has risen sharply.
Mugwort has an extremely wide distribution of production areas. Except for extremely arid and high-cold regions, it is found almost throughout the country. It can grow in wastelands, roadsides, riversides, and hillsides from low altitude to mid-altitude areas, and is also seen in forest-steppe and steppe regions, where it is a dominant species in plant communities in some local areas. It is also cultivated in Mongolia, Korea, the Soviet Union (Far East region), and Japan. Mugwort reproduces and grows very easily, has strong adaptability to climate and soil, is cold-resistant and drought-resistant, prefers warm and humid climates, and grows better in moist and fertile soil. In artificial cultivation in hilly and low-to-mid mountain areas, the vigorous growth period is 24-30 °C. When the temperature is above 30 °C, the stems tend to age, branch, and pests and diseases worsen; when the winter low temperature is below -3 °C, the current-year perennial roots do not grow well.
At present, the use of mugwort is not limited to medicine; its uses in food, building materials, home textiles, daily chemicals, and other aspects are also increasing. Wild mugwort can no longer meet the growing demand, and artificial cultivation of mugwort has developed rapidly, already occupying most of the market. The rapid development of artificial mugwort cultivation has also brought some problems. Mugwort produced in different regions, different environments, different climates, and different seasons contains greatly differing active components, and the quality of mugwort also varies. Therefore, there is an urgent need to study standardized artificial cultivation of mugwort so that it can be planted according to standards, obtain mugwort of better quality, and meet market demand. Nanyang, Henan, is located at 32-33° north latitude. Nanyang City is situated in the Central Plains and has a northern subtropical humid monsoon climate, with obvious monsoon advance and retreat and seasonal replacement. Winters are dry and cold with little rain and snow; summers are hot with abundant rainfall; spring warms quickly and rainfall gradually increases; autumn is cool and rainfall gradually decreases. Winter lasts relatively long at 110-135 d; next is summer at 110-120 d; spring and autumn are shorter at 55-70 d each. The annual average temperature in Nanyang is 15 °C, the average monthly temperature in the hottest month, July, is 27 °C, and the average temperature in the coldest month, January, is about 1 °C. The annual rainfall is 800 mm, and the annual frost-free period is 220-245 d. The ancients once described Nanyang's good climatic conditions with the poem line, "If there is rain before spring, flowers bloom early; if there is no frost after autumn, leaves fall late." Nanyang, Henan, has suitable climatic conditions, which are extremely favorable for the growth of Wan mugwort and suitable for artificial cultivation and planting. In recent years, the planting area has gradually expanded. The planting area of Wan mugwort has exceeded 4,666.67 hm2, forming the Wan mugwort brand, and standardized planting is extremely important. With reference to relevant literature and local planting techniques, this paper standardizes the mugwort planting process, which is of great significance to standardized mugwort planting and its industrial development.
1 Land Selection and Preparation
1.1 Land Selection
Mugwort has strong adaptability, prefers sunlight, is drought-tolerant, and is relatively cold-tolerant, with no strict requirements for soil conditions [19]. However, neutral soil with sufficient sunlight, deep soil layer, good soil permeability, and rich organic matter is preferable, and fertile, loose and moist sandy loam and clay loam with good drainage grow well. In order to save land resources, wastelands, roadsides, riversides, and hillsides in hilly and other areas should be selected for reasonable layout. Both sloped land and flat land can be planted, and it can also be planted in front of and behind houses and in field corners. However, as medicinal and edible mugwort, cultivation must not only obtain relatively high yield, but more importantly ensure the quality, safety, and medicinal efficacy of mugwort raw materials. Therefore, the air around the planting plot should be clean and free of floating dust, there should be no nearby domestic sewage or industrial water pollution, and air quality should comply with the provisions of the national standard GB 3059-2012.
1.2 Land Preparation
After the plot is selected, deep plowing is carried out first, with a plowing depth of more than 30 cm. Deep plowing of the land can not only loosen the soil, increase soil temperature, and improve moisture conservation capacity; it can also make full use of the nitrogen, phosphorus, and potassium elements accumulated under the plowed soil; at the same time, it also plays a partial role in weed control, basically burying all of the year's grass seeds deeply, which can remove about 50% of the weeds the following year. The key is to bury deeply the non-mugwort-specific herbicides that have not decomposed in previous years, eliminating their impact on mugwort growth. When soil moisture is too high during deep plowing, the soil should be properly aired (sun-dried) to prevent failure to break clods during rotary harrowing and the appearance of overly large surface clods and too many dead clods, which affect planting.
1.3 Fertilization
If farmyard manure is available, 30-45 t/hm2 of thoroughly decomposed organic farmyard manure can be applied all at once in combination with plowing and harrowing land preparation; or a layer of thoroughly decomposed dilute human and livestock manure can be spread as base fertilizer. If no farmyard manure is available, granular mugwort-specific organic fertilizer can be selected and evenly broadcast at about 750 kg/hm2 after deep plowing and before rotary harrowing. The effective element content indicators for use as mugwort organic fertilizer are: organic nitrogen, phosphorus, and potassium content above 20%, amino acid content over 20%, organic matter over 20%, humic acid greater than 5%, sulfur element content greater than 10%, and no harmful substances such as heavy metals.
1.4 Bed (Plot) Preparation
After the soil is harrowed and broken up, begin preparing beds (plots). The bed (plot) width is about 5 m (depending on the plot conditions), convenient for manual weeding and mechanical operations. A shallow ditch is opened between every 2 beds (plots), with a depth of about 20 cm and a width of about 30 cm, to facilitate waterlogging prevention and drainage. The middle of each bed (plot) is high and both sides are low (forming a turtle-back shape), with a height difference of no more than 1.5 cm, to facilitate drainage and irrigation. Drainage ditches should be opened around the plot, with a depth of about 50 cm and a width of more than 60 cm, to facilitate irrigation during drought and drainage during waterlogging. After land preparation, spray 1 application of mugwort-specific herbicide (which decomposes upon contact with water) to seal and kill weeds, and seedlings can be planted after 10-15 d.
2 Seedling Propagation
2.1 Seed Propagation
Seed propagation should be sown in early spring. In March-April, direct seeding or seedling raising and transplanting can be carried out. For direct seeding, the row spacing is 40-50 cm. After sowing, the covering soil should not be too thick, preferably 0.5 cm, or just enough to cover the seeds. When the seedlings are 10-15 cm high, thin the plants according to a plant spacing of 20-30 cm [20].
2.2 Division Propagation
Mugwort has strong tillering ability. Generally, 1 mugwort plant can tiller into several to dozens of plants in one year and can be used as material for division propagation. Therefore, most production uses division propagation, which is also the main propagation method in current artificial cultivation. Every year in March-April, when the seedlings growing from rhizomes are 15-20 cm high, when the soil is moist, preferably after rain or after watering, dig out the whole mugwort plant and plant it at a row and plant spacing of 45 cm x 30 cm. If there is no precipitation 2-3 d after cultivation, drip irrigation should be used to preserve soil moisture.
3 Planting
The row and plant spacing for ordinary planting is 45 cm x 30 cm (75,000 plants/hm2); the row and plant spacing for dense planting is 45 cm x 15 cm (150,000 plants/hm2); the row and plant spacing for reasonable dense planting is 45 cm x 20 cm (105,000 plants/hm2). One plant per hole. On relatively sticky yellow soil or black soil, the planting depth is about 5-8 cm; on sandy soil or mabone stone soil, the planting depth should preferably be 8-10 cm.
Mugwort planting can also be semi-mechanized. One person drives a tractor with a plow to open furrows, one person places seedlings, and one person broadcasts mugwort-specific organic fertilizer (if base fertilizer has been applied, no additional fertilizer is needed). In the first plowing, place mugwort seedlings, paying attention to the interval and depth of the furrows opened by the plow and the interval and depth of seedling placement; in the second plowing, broadcast mugwort-specific organic fertilizer with a furrow depth of 15-20 cm, so that the turned-out soil just covers the mugwort seedling roots from the first plowing; the third plowing follows the standard of the first plowing, and the soil turned out by the third plowing just covers the organic fertilizer from the second plowing, and so on until planting is completed. After finishing, check whether there is exposed root phenomenon. If so, promptly cover it with soil.
4 Field Management
4.1 Cultivation and Weeding
After the beginning of spring, when the daily average temperature reaches 9-10 °C, when mugwort root buds have just sprouted but not yet emerged from the ground (promptly push aside the surface soil to observe), maintain a certain degree of soil moisture and use a sprayer to apply a full-coverage spraying of mugwort-specific herbicide for sealing, and by no means leave blank omissions. After mugwort seedlings emerge, if weeds still remain, carry out cultivation and weeding once each in late March and early April, requiring uniform cultivation, with depth not greater than 10 cm. Weeds at the mugwort roots need to be pulled by hand. After the first harvest, for plots where weeds still remain, use a small-nozzle sprayer to spray and kill weeds in the gaps between mugwort plants, preventing splashing onto the mugwort roots; after the second crop of mugwort buds emerges, if a small amount of weeds still remains, carry out manual weeding. Herbicides should be used under the guidance of technical personnel. It is strictly forbidden to choose herbicides privately without technical guidance. When other crops in adjacent plots are treated with dicotyledonous or Asteraceae herbicides, splashing onto mugwort is strictly forbidden. After each harvest, if weeds still remain on the ground, especially weeds bearing grass seeds, they should be collected promptly and piled at the field edge for burning. Grass seeds are strictly forbidden from falling into the field.
4.2 Topdressing
At the seedling stage of each crop, preferably when the seedlings are about 30 cm high, choose a rainy day to evenly broadcast mugwort-specific seedling-promoting fertilizer along the rows at 60-90 kg/hm2. If it is a sunny day, dissolve it in water and apply it around the roots (concentration within 0.5%) or spray it on the leaves; in wet weather, topdressing can also be carried out together with cultivation and soil loosening. First broadcast the mugwort-specific fertilizer, then loosen the soil, with a loosening depth of 10 cm. Chemical fertilizer to promote seedlings is only suitable for the first crop planted in the first year. In subsequent growth periods [Jishan Huayao] (that is, the second crop, third crop, etc.), chemical fertilizer must not be used, otherwise it affects the accumulation of active components and reduces mugwort quality.
4.3 Irrigation
Mugwort has strong adaptability, and before planting the bed (plot) surface has already been prepared into a turtle-back shape, with corresponding drainage ditches. Do timely work of clearing ditches and drainage on rainy days and after rain to prevent water accumulation from causing waterlogging damage. In dry seasons, when seedlings are below 80 cm high, carry out leaf-surface sprinkler irrigation; when seedlings are above 80 cm high, carry out full-orchard flooding irrigation.
5 Harvesting
The first harvest period for mugwort leaves is in early June. Harvest promptly on sunny days, cut the aboveground stems and branches with leaves, and separate stems from leaves. Spread them in the sun to dry, or dry them at low temperature, then pack and store them. In early to mid-July, choose fine weather to harvest the second crop. Harvest the third crop around the time of frost, and carry out winter field management [21].