Detailed Explanation of Key Techniques for Astragalus Planting and Management

Astragalus is a perennial herbaceous plant whose roots are used as medicine, yielding 400--500 kg per 667 sq m annually, and is a crop with relatively high economic value. It belongs to the Fabaceae family, Astragalus genus. Common names: membranous milkvetch, mongolian milkvetch. The plant height is about 40--70 cm. The leaves are pinnately compound, with alternate leaflets that are elliptical or oblong. It has racemes borne at the tips of stems and branches, with papilionaceous corollas that are pale yellow. The pods are semicircular, yellowish-brown, slightly lignified, and not easily broken. Astragalus has very strong adaptability and can be grown in most soils. It is drought-tolerant and cold-tolerant, and can overwinter in the field, but it is susceptible to waterlogging and should not be planted after itself or on the same plot repeatedly.

(1) Cultivation Techniques

1. Site Selection and Land Preparation: Choose suitable neutral or slightly alkaline sandy soil or sandy loam plots. When tilling, deep plow 30--40 cm. Apply 4000 kg of farmyard manure per 667 sq m as base fertilizer, along with 25 kg of diammonium phosphate or 50 kg of phosphate fertilizer. If conditions permit, 50 kg of cake fertilizer can be used. Turn the fertilizer into the soil, rake level, then open furrows and irrigate to settle the soil. After it dries slightly, level it again and prepare for sowing.

2. Seed Treatment: Before sowing, use the boiling water germination method. That is, place the seeds in boiling water, stir for one minute, immediately add cold water to adjust the water temperature to 40, soak for two hours, pour off the water, cover with a wet cloth, and let them sweat for 12 hours. Once the seeds swell or the outer coat cracks, they are ready for sowing.

3. Sowing: (1) Sowing time. Spring sowing is from the Spring Equinox to Qingming Festival; summer sowing is around the Summer Solstice; autumn sowing does not produce seedlings in the same year.

(2) Seeding rate. 1·5--2 kg per 667 sq m. (3) Sowing depth. Open shallow furrows 3 cm deep with a row spacing of 22 cm, scatter the seeds in the furrows, cover with soil and press lightly.

4. Field Management: After sowing and before emergence, if the weather is not dry and the beds are moist, generally no watering is needed. When the seedlings have 4--5 leaves, thin them. When the seedlings are 10 cm tall, set the plants at a spacing of about 8--10 cm. Depending on soil fertility, the planting density should be controlled at 2·5--3·5 ten-thousand plants per 667 sq m. After setting the plants, generally do not water, keeping the surface slightly dry and the soil loose to encourage downward root growth. Water 3 times each year in May, June, and September. Apply topdressing according to soil fertility. If the soil is poor and the base fertilizer is insufficient, apply topdressing twice: at the seedling stage and the early flowering stage. If the soil fertility is relatively high and the base fertilizer is sufficient, topdress at the early flowering stage. The total topdressing amount is 15 kg of urea and 50 kg of fermented cake fertilizer.

(2) Control of Diseases, Pests, and Weeds

1. Powdery mildew: During the outbreak period from June to August, fungicides such as 20% triadimefon powder, 20% Tebuconazole, 70% thiophanate-methyl, and 70% mancozeb can be used at 500--800 times dilution for spray control. Spray once every 7--10 days, for 2--3 consecutive sprays.

2. Red root disease: This occurs throughout the entire growth period of astragalus. It can be controlled by drenching the roots with 55% Dexon, or by spraying fungicides such as Eurasia Kangkuiba, 32% Kejun, and 25·9% Ziguang 007 at 500--800 times dilution. Treat once every 7--10 days, for 2--3 consecutive treatments.

3. Bean pod borer and cotton bollworm: Insecticides such as 0·2% Abamectin EC, 40% Ruitian No. 1, 25% Kefeng Shachongxing, and 20% Shachongwang can be sprayed at 1000--1500 times dilution for control.

4. Weeds: To control weeds at the seedling stage, 48% trifluralin EC can be used at 0·1 kg per 667 sq m, mixed with 30 kg of water and sprayed to control grass weeds.

(3) Harvesting and Processing

1. Seed Collection: In summer and autumn, when the pods mature and droop and the seeds turn brown, harvest them. Collect as they mature; otherwise the seeds will scatter on the ground. After harvesting the pods, dry them in the sun and thresh them, removing impurities, shriveled seeds, and insect-damaged seeds. Store in jars or cloth bags, not in plastic bags, to avoid affecting the germination rate.

2. Root Processing: From Cold Dew to Frost's Descent 2--3 years after planting, when the aboveground stems and leaves wither, dig out the roots. Carefully dig out the roots, shake off the soil, dry them in the sun, and tie them into small bundles for medicinal use.