What are the growing conditions for Astragalus membranaceus? The soil must be fertile and well-drained
AbstractAstragalus membranaceus is a deep-rooted plant that prefers cool, humid conditions and has strong drought tolerance. Because its seed coat is hard and difficult to break and its water absorption is poor, the germination rate is low. Therefore, it is only suitable for planting in fertile, well-drained sandy soil, and cannot be planted in heavily saline-alkali land, waterlogged lowland, clay and other such places, is not suitable for continuous cropping, and cannot be rotated with potato, flax and the like.
Growing conditions for Astragalus membranaceus
Astragalus membranaceus is a deep-rooted crop that prefers cool conditions and tolerates drought. It generally grows in fertile land rich in humus, and can also be planted in moderately to slightly acidic sandy loam with strong water absorption, good drainage, loose soil texture, and direct sunlight with dryness. Heavy clay soil can slow root growth and in severe cases even cause deformity; thin soil layers lead to tangled, highly branched roots in a “chicken claw shape.” Flat land or sunny hillside plots can also be used for planting.
The provinces and regions of Northeast China, Northwest China and North China are all suitable for growing Astragalus membranaceus. The preceding crops are best as gramineous crops; continuous cropping must absolutely be avoided, and it also cannot be rotated with potato, flax and the like. It is not suitable for planting in heavily saline-alkali land, waterlogged lowland, clay and other such places. In the first year of direct sowing it does not flower; only in the second year does it flower, set seed and produce seeds.
Cultivation techniques for Astragalus membranaceus
1. Plot selection for planting: suitable for planting in mountain and river land at higher altitude, and in cold, shady and humid places.
2. Selecting the previous crop: repeated cropping must absolutely be avoided, especially continuous cropping with potato, flax and Atractylodes macrocephala; avoid rotation with leguminous crops.
3. Fertilizing and land preparation: choose as far as possible plots of moderately alkaline sandy loam or soft sandy soil with relatively high terrain, fertile and loose soil, and good drainage and irrigation conditions. When plowing and preparing the land, the stems, leaves and stalks should be fully composted into humus, with more than 5000 kg of barnyard manure and 50 kg of cake fertilizer (according to GAP standards, use little or no pesticides and chemical fertilizers; the plot scale area should be selected in regions with no pollution sources), level the soil and harrow it fine, and cover waterlogged-prone curved areas with plastic film.
4. Seed treatment: the outer seed coat has a layer of pectin, and the hard seed coat leads to poor water absorption and a low emergence rate. For sowing treatment, one of the following methods may be chosen according to specific conditions.
(1) Boiling water scarification: put the seeds into boiling water and stir for 1-2 minutes, then put them into ice water to lower the temperature to 50 degrees, then soak in the water for about two hours and pour off the water. Steam the seeds together with a gunny sack for 12 hours; once the seeds swell or crack they can be sown.
(2) Sulfuric acid treatment: soak slightly late-maturing, hard seeds in sulfuric acid at a concentration of 70-80 for about 4 minutes, rinse clean for about 30 minutes, and then they can be sown.
(3) Fine sand abrasion: add fine sand to abrade the seed coat so it absorbs water, improving the seed germination rate. After treatment, soak in warm water at about 30-50 degrees for 3 to 4 hours, and sow after they have soaked and swelled.
5. Planting methods
(1) Direct sowing method: manually treat new seeds; from the end of March to early April, when temperatures rise, begin spring sowing after the land has completely thawed, or winter sowing before the ground freezes. Seeds for winter sowing do not need treatment. On leveled land, use a row spacing of 30 cm and a plant spacing of 12 cm; after broadcasting the seeds, cover with 2 cm of soil and roll lightly; the sowing rate is 3 kg per mu.
(2) Seedling raising and transplanting: raising seedlings and transplanting can, to a large extent, reduce problems such as low yield, poor quality and difficulty in raising seedlings in direct sowing. In spring and summer, after seed treatment is completed, evenly broadcast at a sowing rate of 7 kg/mu in the field, then cover with 2 cm of soil, and finally spread a layer of fine sand. During drought, sprinkle and irrigate with more water; in about 30 days the seedlings will be complete. During this period, separate the seedling spacing by row and plant spacing of about 7 cm, carry out weeding twice, and pay attention to pest control.
Dig them out in early to mid-October of the same year and bury them in soil to keep warm, or dig up the seedlings before sprouting the next year and transplant them into the field; for transplanting, open furrows at a distance of 20 cm and a plant spacing of 10 cm, place the seedlings obliquely and flat, keep the seedling heads upright at 3 cm from the ground, level with a hoe and roll lightly.
6. Field management
(1) Thinning and final thinning: when the seedlings grow to about 3 cm, thin them and fill gaps by replanting; when the seedlings are 10 cm tall, finalize the stand at a plant spacing of 12 cm. Hoe weeds and loosen the soil; water only in especially dry conditions.
(2) Topdressing fertilizer: Astragalus membranaceus likes fertile land, and in addition to the base fertilization it also needs multiple topdressings. The first is when the young seedlings emerge and show a blue-green color, topdress with farmyard manure; the second is after cultivating and hoeing weeds, topdress with pen manure; the third is after the plants wither in winter, topdress with 2000 kg/mu of high-quality farmyard manure and 150 kg/mu of cake fertilizer, open a furrow between the rows, mix evenly for fertilizing and earth up.
(3) Irrigation and drainage: after final thinning, keep the ground dry and do not water. Letting the soil lie and the roots be exposed to the sun is beneficial to root and stem growth. If the climate is dry, water moderately. In the rainy season, guard against waterlogging and root rot.
(4) Pest and disease control: when pests and diseases are found during the growing period, use 90% solid trichlorfon made into a 1000-fold solution for drip irrigation of the plants; for aphids, spray with 40% dimethoate emulsifiable concentrate 1000-fold solution, and spraying during the green fruit stage also has the effect of controlling the Astragalus membranaceus seed chalcid; for the bean pod borer at the early larval stage, use 50% malathion 1500-2000-fold solution; for powdery mildew, spray with lime sulfur mixture at 0.1-0.3 degrees Baume, or spray with 70-100 g/mu triadimefon made into a 500-fold solution.
7. Selecting and retaining good seed
When harvesting Astragalus membranaceus, priority should be given to selecting those with thin, weak and short aboveground roots and stems, so that the underground part will have long, plump roots; roots that do not flower in the current year are retained for planting the next year. Cut off the secondary roots from the root and stem near the ground, and plant them in well-fertilized fields at a row spacing of 40 cm, a plant spacing of 26 cm, and a furrow depth of 20 cm. With the buds pointing upward, place the seed roots vertically and flat in the dug furrow, keep the roots 3 cm from the ground, fill with soil and press lightly. They flower and bear fruit from July to September; harvest when they mature and turn brown. Dry them in the sun, peel off the seeds, put them in gunny bags, and store them in a dry, ventilated place for later use.
8. Harvesting and processing
As long as management methods are appropriate, Astragalus membranaceus can be harvested in the same year when sown in winter or transplanted in spring, and it can also be harvested after three years. Generally in early January, when the stems and leaves wither, cut off all the aboveground stems and leaves; in lowland, open a deep furrow of about 65 cm, then turn the soil and pull out the roots, remove the mud and cut off the rhizome head, dry in direct sunlight until 70 to 80 percent dry, cut off excess lateral roots and fibrous roots, tie into small bundles with straw rope, then dry thoroughly in the sun, and it can be sold. Perennial fresh goods for export need to undergo peeling processing. Just dry them in the air.