Detailed Explanation of Key Points of Notoginseng Cultivation Techniques: A Guide to Growing Medicinal Herbs
I. Site Selection and Land Preparation
Site selection: The principle of "slopes are better than flat land" should be grasped in site selection, with a slope generally of 5° to 15°, and among mountain slopes, south-facing and southeast-facing slopes are best. For cultivating notoginseng, loam and sandy loam are suitable, requiring loose soil, good drainage, and rich in humus, with a soil pH of 5 to 7. Notoginseng cannot be continuously cropped; it is suitable to choose a plot that has not grown notoginseng within six years as the planting site, and virgin land or abandoned land is often chosen as the most ideal for raising seedlings. In addition, the previous crop is best as corn or leguminous crops, and vegetables, buckwheat, and solanaceous plants should be avoided. To cultivate notoginseng in arid climate areas, the site selection should also be close to a water source.
Land preparation: The land for cultivating notoginseng should be prepared 4 to 5 months before planting or sowing. Usually, virgin land is plowed in June to July, and previously cultivated land in August, with a plowing depth of 30cm (generally not less than 15cm). Base fertilizer is applied in combination with plowing, at a rate of 1,500 to 2,500kg of decomposed barnyard manure per 667 sq m, mixed with 40 to 100kg of lime powder. From plowing to sowing or transplanting, the land should also be plowed and turned 2 to 3 more times to accelerate the decomposition of organic matter. For the final plowing and turning, tree roots, weeds, stones, and other debris also need to be picked out. Before sowing (planting), beds need to be made, with a bed surface width of 140~160cm, a bed height of 20~25cm depending on the slope, a bed ditch with a top width of 30~50cm and a bottom width of about 20cm. Notoginseng beds should be narrow at the top and wide at the bottom, with the soil firm on top and loose below, in a curved-tile shape. In some places, after making the bed, a wooden board is used to compact the bed surface, and then a 15cm-thick layer of wormwood is spread on the bed surface and burned, to increase the readily available nutrients in the bed and to disinfect the bed surface.
Construction of the Shade Shed
1. Construction of a shade shed with special sunshade netting: Mark points and plant forks at 3.0 m × 1.8 m, lay large poles (or iron wire) and fix them, cover with sunshade netting, add a pressure-resistant film line (iron wire) at the middle of two rows of large poles, and use iron wire in each gap in a "V" shape to pull the film line tight, fixing it to the middle of the left and right seven-forks, so that the shade shed takes a rice-like shape to facilitate wind protection and drainage. The height of the shade shed is preferably about 1.8 m from the ground and about 2 m from the bottom of the ditch. On the rounded edges, ground anchors are used to pull the film line tight and fix it, and the entire sunshade net surface should be pulled taut.
2. Construction of a traditional shade shed: Mark points and plant forks at 1.7 m × (1.7 m~2.0 m), lay large poles (or iron wire), fix them, place 4~5 small poles in each empty position, cover with roof grass (crop straw, but it is best not to use corn stalks), add 2~3 battens, adjust the light, and fix. Attention should be paid to making the light transmittance of the shade shed as uniform and consistent as possible.
II. Planting Methods
Sowing and Transplanting
Notoginseng cultivation uses the method of raising seedlings and then transplanting. The time for sowing and transplanting is generally from mid-to-late December to mid-to-late January of the following year. Seedlings are raised for one year, and after transplanting they grow for three years before being harvested and processed.
Sowing
Wash the seeds clean with clear water and select plump seeds that sink to the bottom, soak them for 2h with a 300-fold dilution of 65% zineb or other fungicide, remove them, mix with bone meal or calcium magnesium phosphate fertilizer, and then sow. Because in the Yunnan and Guangxi production areas, the natural conditions during the period from sowing to seedling emergence (mid-November to mid-to-late February of the following year) are exactly suitable for the natural after-ripening of notoginseng seeds, and the after-ripening time is also sufficient, so special artificial germination promotion is not needed. Including the last batch of seeds harvested in early January, if sown promptly after harvest, after-ripening can also be completed by the end of April of that year, and seedlings can emerge quickly after sowing.
Notoginseng sowing mostly uses hole sowing or drill sowing. Many units make the bed, press marks, sow, and then cover with 2~3cm of soil-fertilizer mixture (decomposed barnyard manure mixed with an equal volume of bed soil). After sowing, the bed surface should be covered with a layer of rice straw or other seedless wormwood (3~5cm thick). Each 667 sq m of seedling field uses 70,000 to 120,000 seeds, equivalent to 10~11kg of red seeds (fruit).
Transplanting
Notoginseng is transplanted one year after seedling raising. Transplanting is generally carried out from December to January of the following year. It is required to lift seedlings, select seedlings, and transplant at the same time. 1~2d before lifting seedlings, water the bed surface first to soak the topsoil thoroughly. When lifting the roots, strictly prevent damage to the root strips (the production areas call the roots "zi tiao") and buds. When selecting seedlings, diseased, injured, and weak seedlings should be removed, and good seedlings should be graded for cultivation. Before transplanting, the seedlings should be graded for cultivation to ensure seedling quality. Notoginseng seedlings are graded into three levels according to root size and weight: those with similar root strip length and a weight of more than 2kg per thousand roots are grade one; those with a weight of 1.5~2kg per thousand roots are grade two; and those with a weight below 1.5kg per thousand roots are grade three.
When placing seedlings for transplanting, the bud heads throughout the field should face the same direction to facilitate management. On sloping land and gentle sloping land, place seedlings from the lower part toward the higher part; the roots of the first row of seedlings face up the slope, and from the second row onward the roots face down the slope and the buds face up the slope; on both sides of the bed, the roots face inward and the buds face outward. Transplanting row spacing: grade 1 and 2 seedlings are 18cm; grade 3 seedlings are 15cm. Plant spacing: grade 1 seedlings are 18cm; grade 2 and 3 seedlings are 15cm. In production areas, a shallow ditch of 3~5cm is mostly opened according to the specified row spacing, then the roots are placed flat in the ditch, with the buds in the same direction. After placing, cover with soil and then cover with grass (5cm thick). Before planting, the seedlings should be disinfected, mostly by dipping the notoginseng roots in a 300-fold dilution of 65% zineb (so that the entire outside of the notoginseng root has a layer of medicinal film), then immediately removing them to dry and planting promptly.
III. Field Management
1. Weeding and earthing up: Notoginseng is a shallow-rooted medicinal plant, with most of its root system concentrated in the top 15cm layer, so intertillage and loosening of the soil cannot be done. Weeding should be carried out at any time; pull weeds whenever they appear, and do so early and while they are small, otherwise pulling large weeds may bring out notoginseng roots or loosen them, affecting growth, development, and yield. When weeding, if exposed notoginseng roots are found, they should be promptly covered well with fine soil, and the grass on the bed surface should be spread and leveled evenly again.
2. Irrigation and drainage: Notoginseng is not tolerant of high temperatures or drought, so in high-temperature or dry seasons, water frequently and always keep the bed surface moist. Notoginseng not only fears drought but also fears excessive humidity, so the amount of irrigation water cannot be large; water less at a time, frequently, and evenly. Neither splashing water nor flood irrigation can be used. What production areas often call "rinsing water" means exactly this. When the rainy season comes, drainage ditches should be dredged well, strictly preventing water accumulation in the field, and attention should be paid to reducing the air humidity in the field.
3. Topdressing: Notoginseng cultivation requires multiple topdressings every year. The current experience-based practice is:
In the early stage of seedling emergence and leaf unfolding, broadcast plant ash on the bed surface 2~3 times, with 50~100kg per 667 sq m each time.
In the late stage of leaf unfolding, that is, during April and May, apply a mixture of organic fertilizer and smoked soil once a month, with 1,000kg per 667 sq m; from June to July, apply another topdressing once a month, at this time the topdressing amount is 2,000kg per 667 sq m, and seed-production fields should also be topdressed with 15kg of superphosphate per 667 sq m.