How to Plant Lotus Root Seedlings? A Detailed Guide to Cultivation Methods
Lotus root is the swollen rhizome of the lotus plant (Nelumbo nucifera) in the water lily family. It tastes slightly sweet and crisp, can be eaten raw or cooked, and has considerable medicinal value. Its roots, leaves, flowers, and fruits are all treasured. It is suited to growing in hot, rainy seasons. South of the Yangtze River it is mostly planted in early March to April, while in the Beijing area it is mostly planted in early May. Let's take a look below at how to plant lotus root seedlings!
Cultivation Conditions for Lotus Root
1. Temperature: Lotus root can only sprout when the seed rhizomes are above 15°C. During the vigorous growth period, the temperature should be 20-30°C, with a water temperature of 21-25°C. In the early stage of rhizome formation, a relatively high temperature is also required, while in the later stage a large day-night temperature difference is needed. During dormancy, the temperature should be kept above 5°C; below 5°C it is prone to freezing damage.
2. Light: Lotus root is a light-loving plant and does not tolerate shade. It requires sufficient light during the growing period, and is not strict about day length. Sufficient light in the early stage promotes the growth of stems and leaves, while sufficient light in the later stage favors flowering, fruiting, and the plumping of the rhizome.
3. Water: During the sprouting and growth stage of lotus root, a water level of 5-10 cm is appropriate; during the vigorous growth stage, a water level of 30-50 cm is required. Afterward, as the plant flowers, fruits, and forms rhizomes, the water level should gradually be lowered. For overwintering dormancy, it is only necessary to keep the soil fully moist or maintain shallow water.
4. Soil: For lotus root growth, loam and clay loam rich in organic matter are most suitable. The organic matter content should be at least above 1.5%, and the soil pH should be between 5.6 and 7.5, with 6.5 being most suitable. Nitrogen, phosphorus, and potassium should all be given equal importance.
Planting Methods for Lotus Root
1. Selecting good varieties: Choose seed rhizomes that are free of wounds and disease, have good varietal characteristics, are large in size, have complete growing tips, intact tail ends, complete terminal and lateral buds, and thick, plump rhizome nodes. Use early-maturing, high-yielding shallow-layer lotus root varieties, and try to keep them uniform in size.
2. Fertilizing and preparing the field: It is better to choose a fertile field with a relatively deep mud layer, convenient irrigation and drainage, and where rice was planted the previous year. Fifteen days before planting the lotus root, apply per mu 2000-3000 kg of decomposed organic fertilizer, 150 kg of cake fertilizer, 70 kg of superphosphate, and 80 kg of quicklime.
3. Planting time: Choose a sunny afternoon and first arrange the seed rhizomes in the field according to the required row and plant spacing, then dig furrows by hand according to the size of the rhizomes and plant them. The front end of the seed rhizome should slope downward, with the rear end slightly exposed above the soil surface, which helps it receive light and air and promotes sprouting.
4. Planting method: The depth of insertion into the mud should be such that the mud covers the rhizome and buds. When planting near the field ridges around the perimeter, be careful to always turn the rhizome heads toward the center of the field. When the field is level and the mud has settled, open furrows or pits for planting.
Field Management of Lotus Root
1. Weeding and removing leaves: About one month after planting lotus root, when the floating leaves gradually wither, remove the dead leaves. Before the rows close, weed together with topdressing. When weeding, walk along both sides of the curled leaves. When flower buds appear or flowers open, often bend the flower stems over but do not break them off.
2. Reasonable topdressing: When there are 3-5 standing leaves, apply per mu 25-30 kg of high-nitrogen-and-phosphorus compound fertilizer. When standing leaves fill the field, apply per mu 30-35 kg of high-nitrogen-and-potassium compound fertilizer. When the terminal leaf appears, apply per mu 15-20 kg of high-potassium compound fertilizer or 10-15 kg of pure potassium fertilizer.
3. Adjusting the water level: From planting to before sprouting, irrigate with shallow water of about 5-10 cm to raise soil temperature and help seedlings emerge. As standing leaves and branches grow, gradually deepen the water layer to 15-20 cm. During the rhizome-forming period and before harvest, shallow water should be irrigated.
4. Straightening the rhizome heads: In June, the lotus runners grow rapidly in all directions and need to be manually trained. At noon, dig open the mud, lift the runners, turn them toward empty areas, and bury them back into the soil.
5. Maturity and harvest: When most of the aboveground standing leaves have withered and yellowed and the rhizomes are fully mature, they can be harvested successively. Lotus root harvest is divided into green lotus root and withered lotus root. Green lotus root is mostly harvested in August, while withered lotus root is harvested from after the beginning of autumn to March-April of the following year.
Pest and Disease Control for Lotus Root
1. Insect pests: Lotus root pests include aphids, cotton leafworms (Spodoptera litura), and slug moths. They can be sprayed with 90% trichlorfon at 800-1000 times dilution or 40% dimethoate at 2000 times dilution. Water maggots suck the sap of lotus root roots, stems, and leaves; lime can be applied to repel and kill them, at 10-15 kg per mu.
2. Fusarium wilt: Keep the lotus field clean and prevent oil pollution from contaminating the field. Sewage and soapy water can also cause lotus leaves to wither and die. Moreover, lotus root is very sensitive to herbicides, so herbicides must never be applied in lotus fields.
3. Viral disease: When controlling lotus root viral disease, choose disease-resistant varieties and promptly control aphids (the transmission vector). In the early stage of disease onset, spray 1.5% plant virus inhibitor emulsion at 1000 times dilution.
4. Black spot disease: In the early stage of disease onset, remove diseased leaves and spray for control. You can use 70% thiophanate-methyl at 1000 times dilution, or 65% zineb at 600 times dilution, or Bordeaux mixture at 1:1:166-200. Spray once every 10 days, for a total of 2-3 sprays.
5. Rhizome rot: In severely affected fields, implement a 2-3 year crop rotation. You can use 70% thiophanate-methyl at 1000 times dilution or 75% chlorothalonil at 800 times dilution to spray and seal the seed rhizomes. When disease occurs, mix 0.5 kg of 75% chlorothalonil with 30 kg of dry soil and broadcast it into the shallow-water field.