Detailed Explanation of Water Chestnut Planting Methods and Technical Key Points

Water chestnut (English name: water chestnut, scientific name: Eleocharis dulcis), also known as matai, water chestnut, shao, fuzi, wuyu, puji, dili, belongs to the monocotyledonous family Cyperaceae, is a perennial rooted herbaceous plant, oblate, pointed at the top, smooth and glossy surface, purplish-red or dark brown, growing in ponds and marshes, with dark green clustered stems above ground and edible corms underground. Because its shape resembles a horse's hoof, people also call it matai. Its appearance is like a chestnut; not only the shape, but also the nature, flavor, composition and functions are similar to chestnuts, and because it fruits in the mud, it is also called “dili” (ground chestnut).

The water chestnut is native to our country and is an aquatic vegetable suitable for shallow-water cultivation, with the underground corm used for food, suitable for both raw and cooked consumption, and can also be processed into starch or used medicinally. The water chestnut is a perennial herbaceous plant, propagated by corms. After the corm is planted, an inconspicuous shortened stem sprouts from the corm, and slender fibrous roots can grow from the basal nodes, without root hairs. From the shortened stem, green leaf-like above-ground stems sprout upward; the leaf-like stems are tubular, upright, hollow, and clustered, and can carry out photosynthesis. Around the shortened stem, stolons sprout and grow horizontally in the soil; some nodes can produce roots and buds, and when the buds extend out of the ground they become individual plants, called branch-type stolons. The tips of some stolons can expand into corms, called corm-type stolons. The corm is oblate, with a smooth surface, dark chestnut or jujube-red when mature, with 3-5 rings. The corm enlargement period is about 70 days. The water chestnut grows vigorously and is easy to cultivate. When cultivated in shallow water with deep soil, rich in organic matter, and fertile and soft, the corms are numerous and plump, with a rosy color. The water depth should not exceed 30 cm, otherwise the above-ground part will grow excessively, affecting corm formation. It has a relatively high demand for phosphorus and potassium fertilizers, and excessive nitrogen fertilizer must be prevented. For temperature, 15-20 degrees is suitable in the early stage, 25-28 degrees is suitable during the branching stage, and 10-20 degrees is suitable during the corm formation stage.

Strict seed preservation to ensure full seedlings. For seed water chestnuts, in the middle and late stages of plant growth in the previous year, the above-ground part must be inspected, and a field with uniformly growing above-ground populations and no pest or disease damage should be selected as the seed-preservation field; this is the primary selection. When harvesting water chestnuts, select corms from the seed-preservation field that are round and neat in appearance, undamaged, with thick and strong buds, and a single corm weight of more than 15 grams, conforming to the characteristics of this variety, and store them over winter; this is the secondary selection.

Water chestnuts can be directly sown, but are mostly. Seedlings are raised and then transplanted. The seedling-raising period can be determined according to local climatic conditions. For spring seedling raising, around Grain Rain, take out the seed water chestnuts and cover them with straw indoors and sprinkle water to promote sprouting. The specific method is: first spread a layer of rice straw on the ground, place the seed water chestnuts densely with the apical buds facing upward, stagger them in 3-4 layers, and then cover the top with straw; or place sand between the seed water chestnuts to separate them, and cover the top with straw. Afterward, spray water to keep them moist. After about half a month, when the buds have grown to about 1.5 cm, remove the rice straw and continue spraying water to keep them warm. When the apical buds reach 10-15 cm in length, they can be inserted into the seedling field. The seedling field should be chosen as a plot sheltered from the wind and facing the sun, with convenient drainage and irrigation. Plow and harrow with water 2-3 times. After leveling the field surface, the seed water chestnuts can be inserted into the seedling field. The row and plant spacing is 20-25×20 cm. Each mu of main field requires 30-35 square meters of seedling field. The seed amount used is 15-20 kg. When planting, separate the branch plants and plant them separately, and maintain shallow water after planting. The main field for planting water chestnuts must be plowed and harrowed repeatedly and given sufficient base fertilizer. When the seedlings are 25-35 cm tall, it is the most suitable planting period. The planting row spacing is 55-65 cm. The planting depth is generally required to be level with the base of the leaf-like stems. After planting, smooth the soil beside the roots, cut off the tips, and keep the seedlings about 20 cm tall to prevent wind from shaking them. After the water chestnuts are planted, 15-20 days. The first intertillage is for weeding the field surface, and after the Beginning of Autumn another intertillage and weeding is done. During the growth period, water management must be strengthened. When planting, irrigate with shallow water of about 3-4 cm to facilitate rooting; when the plants enter the tillering and branching stage, the water level should often be maintained at 6-7 cm; in case of high temperature and drought, the water level should be appropriately deepened. Apply topdressing 1-2 times in the field; drain the water when topdressing, then irrigate again after topdressing. After corm formation, drain the water, but keep the field moist. After the corms are fully enlarged, from the beginning of the above-ground part's death to before the corms sprout the next year, they can be harvested at any time.

Select corms that conform to the characteristics of this variety, are plump and undamaged, have a smooth surface, uniform color, and thick and strong buds as seed for seedling raising. Early-water water chestnuts are raised in late April, and late-water water chestnuts are raised in June to July.

Timely planting

Generally, early-water water chestnut seedlings are planted at 45-70 days of age, and late-water water chestnut seedlings are planted at 25-30 days of age. The row spacing is generally 55-60 cm, and the plant spacing is 25-30 cm. Both main-stem plant-clump seedlings and branch seedlings can be used as planting seedlings. The planting depth should be suitable for stable planting. If the seedlings are too tall when planting, cut off the tips and keep the leaf-like stems 25-30 cm tall, so as to avoid being broken by wind after planting and shaking the root stock.

Water layer management

For early-water water chestnuts, maintain shallow water of 2-3 cm in the field at the initial stage, then gradually deepen it to 7-10 cm. For late-water water chestnuts, immediately irrigate to 6-8 cm after planting. When entering the corm-setting stage, the water level should gradually be lowered to 3-5 cm, and finally maintain 1-2 cm of shallow water for overwintering.??

Topdressing

Generally, 15-20 days after planting, when all have survived and branching begins, after the dew has dried, drain the field water, spread the fertilizer evenly, and restore the water 1-2 days after application. When corm setting begins, apply fertilizer once more.