What are the key techniques for high-yield lotus root cultivation?

Lotus root, also known as lotus rhizome, is the rhizome of a plant in the lotus family (Nelumbonaceae) and can be eaten as food or used medicinally. It is grown in Jiangsu, Zhejiang, Hubei, Shandong, Henan, Hebei, Guangdong and other places in China. Lotus root belongs to the lotus family. Lotus root is slightly sweet and crisp, and can be eaten raw or cooked; it 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 all can be used as tonics and medicine. Lotus root made into 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 nourishing delicacy for women, children, the elderly and the frail and sickly. Lotus root is rich in vitamin C and minerals, has medicinal effects, benefits the heart, and promotes metabolism and prevents rough skin. It is grown in Jiangsu, Anhui, Hubei, Shandong, Henan, Hebei and other places in China. Lotus root is also called lotus rhizome, and because its underground stem is white it is also named white stem. The Jiangnan poet Chen Zhisui's poem "Ode to the Lotus": “Though in the mud, it is not stained by the mud; the white stem buried in the ground is known to none. In the clear, bright reds and greens, it does not wait for the wind to fill the pond with fragrance.” Lotus root is also an important cash crop in its growing regions.

1. Types

(1) Lotus root

The edible lotus group, with white and pink flowers, has relatively thick and large underground stems. According to different uses it is divided into two types: rhizome lotus and seed lotus. Rhizome lotus is grown for the purpose of harvesting the thick, large underground stem. Its leaf veins are raised, it may or may not produce flowers, it sets no seeds or very few seeds, and the rhizome is thick and large; seed lotus is generally more tolerant of deep water and matures later, its leaf veins are not raised, it has many fruits and large seeds, but its rhizome is relatively small and its quality is poorer.

(2) Flower lotus

The flower lotus group has extremely beautiful flowers and is mostly used for ornament and medicine. It rarely sets fruit, its rhizome is small and fine, and its quality is coarse and poor.

How should lotus root be cultivated to achieve high yield?

Fine land preparation and sufficient base fertilizer

Lotus root grows in soil, and it requires soil rich in humus, soft, smooth and loose, with good aeration; this is most favorable for the growth of lotus root and makes it easy to obtain high quality and high yield. Therefore, before planting lotus root the soil should be deeply plowed, the land finely prepared, and sufficient base fertilizer applied. Generally, before the thaw in late winter, drainage is carried out together with harvesting the lotus root, then the soil is deeply plowed 33-40 cm to allow the soil to fully weather; from the Beginning of Spring to the Spring Equinox, the ground is prepared and manure is spread. The method is: first remove 33-40 cm of topsoil, then use an electric tamper to tamp the bottom of the pond to prevent water and fertilizer leakage. A lotus root pond is generally 16.7 m long and 10 m wide, with the upper part of the pond ridge 50-67 cm wide, the lower part 1 m wide, and 67 m high. Ponds connected to one another must not have a water channel built through. After the lotus pond is prepared, then 3000-4000 kg of human manure and urine per mu, and 4000-5000 kg of rotted organic fertilizer, are applied, and the soil is deeply plowed 4 times in succession to mix the soil and fertilizer evenly and level the ground, so that the pond is as level as a mirror. Finally, water is let in and the pond is trampled; when trampling the pond, first let in shallow water 10-13 cm deep, then repeatedly trample the ground until the pond soil is completely trampled into a soft, smooth mud, and then it is ready for planting.

Plant at the right time and at a reasonable density

1. Selection of seed lotus root. Carefully selecting the seed lotus root before planting is one of the important measures for cultivating strong seedlings and obtaining high yield. For the seed lotus root, one should choose lotus root with thick, large nodes, vigorous buds, no pest or disease damage, and possessing the characteristics of the variety. The thicker and larger the seed lotus root, the better; such seed lotus root has both a large amount of nutrients and vigorous, vital buds, and can promote the rapid growth and development of new runners, thus laying the foundation for the robust growth of the lotus plant. 2. Planting at the right time. Based on many years of practice, from Grain Rain to the Beginning of Summer is the suitable period for planting lotus root. The planting period must not be too early or too late; if too early, the water and soil temperatures are low, sprouting is slow, and the lotus seedlings are not vigorous; if too late, the seedlings are too large, the recovery period after transplanting is long, they are easily bruised or broken during planting, and at the same time the growth period is shortened, affecting yield and returns. 3. Reasonable dense planting with proper methods. The planting density must not be too great or too small; the suitable density is generally a row spacing of 2.3 m, with plants placed one against another, using 400-450 kg of seed lotus root per mu. To make planting easier, the pond water should not be too deep; generally about 10 cm is retained. There are 2 planting methods: one is the slanting planting method, and the other is the flat planting method. When planting, first dig a trench 1-2 m long, 13-16 cm wide and 16-20 cm deep, then place the seed lotus root into the trench with the tip slanting downward, and cover it with 10-13 cm of pond mud on top, enough to cover the buds; when covering with mud, the lotus head should be slightly deeper, and the rear end slightly exposed above the water surface, so as to use sunlight to raise the mud temperature and promote rooting and sprouting. If the flat planting method is used, its runners easily run out of the mud, and the seedlings are easily swayed by the wind, so after planting one must check frequently; if they float out of the water, they need to be replanted. For the planting arrangement of lotus root, an alternating arrangement is used: one row faces south, that is, the lotus tips point in one direction, slightly left or right along the row; the other row faces north, and at both the north and south ends the lotus heads all point toward the pond ridge.

Management after planting. 1. Scientific irrigation and fertilization. Lotus root requires flowing shallow water and sufficient fertilizer. During the seedling growth period after planting, a water layer 10-20 cm deep must be kept in the pond at all times; if the water level is found to have dropped, water should be added promptly. Generally, water is irrigated once every 1-2 days after planting; in this way the water layer in the pond is shallow, which is favorable for receiving sunlight, the soil temperature rises quickly, and the emergence of leaves and runners is promoted. If the water layer is too deep, the pond temperature is low, which is not favorable for the growth of lotus seedlings. After the Summer Solstice less water is irrigated, because the pond bottom has already been tamped firm and does not easily leak; generally water is irrigated once a week. From the Summer Solstice lotus root begins to form, and the Beginning of Autumn is the peak period of lotus root swelling; the water depth should be kept at 33-40 cm.