Key Technical Points for Standardized Cultivation and Management of Lotus Root

Lotus root, a plant of the Nelumbonaceae family. Lotus root is slightly sweet and crisp, can be eaten raw or cooked, and is one of the common table vegetables. Lotus root is also a plant of fairly high medicinal value; its roots, leaves, flower stamens and fruits are all treasures and can be used as tonics and medicine. Lotus root powder can aid digestion and stop diarrhea, stimulate the appetite and clear heat, nourish and strengthen the constitution, and prevent internal bleeding; it is an excellent liquid food and tonic delicacy for women, children, the elderly and those who are weak and prone to illness. Lotus root is rich in vitamin C and minerals, has medicinal effects, benefits the heart, and helps promote metabolism and prevent rough skin.

Lotus root contains starch, protein, asparagine, vitamin C and oxidase components, and also has a high sugar content. Eating fresh lotus root raw can clear heat and relieve irritability, quench thirst and stop vomiting; if fresh lotus root is pressed for juice, its effect is even stronger. Cooked lotus root is sweet and warm in nature and flavor, can strengthen the spleen and stimulate the appetite, enrich the blood and tonify the heart, so it mainly tonifies the five viscera and has the effects of aiding digestion, quenching thirst and promoting body fluid production.

Traditional Chinese medicine holds that lotus root is cold in nature and sweet in flavor. Used raw, it has the effects of cooling the blood and dissipating stasis, and treats febrile disease with vexation and thirst, hematemesis, heat strangury, etc.; used cooked, it can enrich the blood, stop diarrhea, and also strengthen the spleen and stimulate the appetite. Single and proven prescriptions based mainly on lotus root are widely used in clinical practice and have very good results. For example, fresh lotus root juice, taken half a cup each morning and evening, treats pulmonary tuberculosis bleeding, postpartum hemorrhage and nasal bleeding. In addition, fresh lotus root is pounded and squeezed for juice, an appropriate amount of honey is added, stirred evenly and taken in divided doses to treat unremitting vexation and thirst due to febrile disease; half a cup each of lotus root juice and pear juice are mixed evenly and taken to treat phlegm-heat in the upper jiao and dry mouth with cough. The connecting part of the lotus root is called the lotus node, which contains asparagine, tannins, etc., and has relatively high medicinal value. Lotus nodes and lotus root are roughly similar in nature, flavor and function, but lotus nodes place more emphasis on the effect of stopping bleeding.

Standardized cultivation and management techniques for lotus root

1. Preparation of lotus root planting material

Select disease-resistant and high-quality varieties. Whole lotus roots, main lotus roots or daughter lotus roots can be used as planting material. Generally, the smallest lotus root branch is required to have 1 terminal bud, 2 internodes and 3 nodes. Seed lotus roots should carry an appropriate amount of mud, have no major damage and carry no disease, and should be planted as soon as they are dug to keep them fresh. It is advisable that no more than 10 days pass from digging to planting. If they cannot be planted in time, they should be stored in water or kept moist by covering and watering. Those requiring long-distance transport or longer storage must be washed clean, disinfected and packaged. However, the storage time should not exceed 45 days. The seeding rate per mu is 200-250 kg.

2. Tillage, leveling and fertilization

Choose a plot with sufficient water sources, good water quality, good water retention, rich organic matter and far from industrial “three wastes”. Deeply plow 30 cm, harrow level, and remove all weeds as well as dead lotus and lotus runners from previous years. Apply 80 kg of quicklime and 4000-5000 kg of farmyard manure per mu, or apply 25-30 kg each of compound fertilizer and decomposed cake fertilizer.

3. Planting

Hill spacing 1.5-2 m, row spacing 2-2.5 m. Insert the seed lotus root branches obliquely into the mud at a 20-degree angle to a depth of 5-10 cm, with the lotus root head facing inward. Planting holes in different rows are arranged in a staggered pattern forming a plum-blossom shape. The distance from the edge row to the field ridge is half the row spacing.

4. Water and fertilizer management

Irrigation water must meet standards. The field should maintain a water layer year-round. In April-May, a water depth of 5-10 cm is appropriate, and it should deepen as the temperature rises. In the high-temperature season of July-August, the water depth is 10-20 cm; in September-October, the water depth is 5-10 cm; in winter, the water layer in the field should be such that the underground lotus roots do not suffer frost damage.

Generally, topdressing is applied 2-3 times. The first is applied when there are 1-2 standing leaves (25 days after planting), with 10 kg of potassium sulfate, 15 kg of urea or 2000 kg of decomposed human excrement and urine per mu; the second is applied when there are 5-6 standing leaves (about 40 days after planting), with 20-25 kg of compound fertilizer, 10-15 kg of urea or 2000 kg of decomposed human excrement and urine per mu; the third is applied when the terminal leaves appear, with 15 kg of urea or 2000 kg of decomposed human excrement and urine per mu. If green lotus roots are harvested in early to mid-July, or if the field soil fertility is relatively high and the plants are growing vigorously, the third topdressing may be omitted. Before topdressing, appropriately lower the water level; during topdressing, fertilizer must not remain on the leaves, and the lotus runners must not be trampled or damaged.

5. Control of diseases, insect pests, weeds and other harmful organisms

The main diseases of lotus root are rot disease and brown spot disease. Rot disease is mainly controlled by measures such as selecting disease-resistant or disease-free varieties, crop rotation, and field disinfection. Brown spot disease can be controlled by spraying 500-1000 times dilution of 25% carbendazim wettable powder, with a pre-harvest interval of more than 15 days; or by spraying 600 times dilution of 75% chlorothalonil wettable powder, with a pre-harvest interval of more than 15 days; or by spraying 800 times dilution of 25% metalaxyl wettable powder, with a pre-harvest interval of more than 1 day. The main insect pests of lotus root are aphids and tobacco cutworms. For aphids, spray 800 times dilution of 40% dimethoate emulsifiable concentrate, with a pre-harvest interval of more than 7 days. For tobacco cutworms, adopt measures such as manual capture and killing of egg masses and larvae, and use sex pheromones, black light lamps or sugar-vinegar bait to trap and kill adults; 4000-6000 times dilution of 40% fenvalerate emulsifiable concentrate or 3000 times dilution of 4.5% beta-cypermethrin emulsifiable concentrate may also be used for spray control, with a pre-harvest interval of about 15 days for both.