Cultivation techniques of lotus root in artificial pond field

1. Selection of varieties

Seed lotus roots are generally dug up before planting, and the whole lotus roots or larger lotus roots with typical variety characteristics and thicker nodes (i.e. lotus tail) are selected. The whole lotus root on the lotus root must grow in the same direction, so that the lotus whip has regular elongation. If seed lotus root is used as seed, at least two fully mature lotus roots with complete terminal buds shall be cut off at 1.5 cm after the second node, and hand breaking shall be avoided to prevent muddy water from entering lotus root holes and causing rot. The varieties of lotus root mainly include early-maturing lotus root, Elian No.1 and No.3, middle-late maturing lotus root, Meirenhong, Dazihong and Elian No.2. Lotus seeds should be dug, selected, selected and planted with them. If they cannot be planted on the same day, they should be covered with water to keep moisture. Prevent leaf buds from withering. Lotus early cultivation, the general first germination, to prevent premature frost planting, low water temperature and late frost damage caused by rotten seeds and lack of plants. The germination method is as follows: the seed lotus is placed in a warm room, covered with straw from top to bottom, watered 1 to 2 times a day to maintain 20 - 25 DEG C and relative humidity of about 75%, and can be planted after about 20 days and bud length of about 10 cm.

II. Cultivation techniques

1. Lotus pond construction. Dig 40 cm flat underground, use the excavated soil, and hit a 40 cm high earth ridge beside the pond. All sides are lined with cement blocks and covered with plastic film to prevent water leakage. Then use wheat straw or corn stalks to spread evenly in the pool, with a thickness of 40 cm. You can also use wheat bran, spread 20 cm thick on the line. Cover the grass evenly with 10 cm of soil, spreading the soil evenly. Combined with pond lotus root, 2000~3000 jin organic fertilizer and 30 jin compound fertilizer can be applied per mu, and the soil preparation shall be smooth and fertile.

2. Seedling planting. The seed amount per mu is 400~500 jin, and the plant spacing is 0.7×1.5 meters. When planting, the bud head should be inserted obliquely into the soil depth of 10~12 cm, the bud head should be parallel to the soil surface, and the node should be exposed to the ground for 2~3 cm. The lotus buds planted around the field should face the field to prevent lotus roots from growing out of the field. Cross planting is adopted in the field, and the bud head should not only face one direction, so as to make full use of the field space. Seed lotus slightly covered with soil, so that it does not float after irrigation can be. After planting lotus roots, irrigate them to 5~10 cm above the soil.

III. Management techniques

1. Water management. The management principle of water layer is shallow-deep-shallow, that is, only 2~ 3cm shallow water layer is needed at the initial stage of planting, until the first leaf growth period about May 20 after January; the water depth is 15~ 20cm in July ~ August, and 50~ 80cm deep water can be irrigated for a short time if there is a storm. Only 7~8 cm of shallow water is needed in the later stage of growth, and it is necessary to winter in shallow water.

2. topdressing. A total of three topdressing in the growth period, the first leaf period, that is, about May 20, between the rows of 2000~3000 jin of human excrement, urea 10~15 jin, at this time can also be applied green manure. The second time is from June 20 to early July, applying urea 40 jin and compound fertilizer 60 jin per mu. At this time, pay attention to prevent foot on lotus root when planting, fertilizer can not be applied to leaves. The third time is July 15~20, depending on the growth situation, appropriate fertilization can be applied. If the growth is poor, urea 10~15 jin, compound fertilizer 40 jin, calcium superphosphate 40 jin and plant ash 1000 jin are applied per mu.

3. Diseases and pests. There are few diseases and insect pests in lotus roots, which can only be found in old lotus roots. There are aphids, Spodoptera litura, root eating golden insects, corruption, virus disease, brown spot disease and so on. Control method and vegetable field control the same, but need to add pesticide adhesive (washing powder, detergent).

4. Water layer regulation and chemical weeding. According to the adaptability of lotus root to water level, it can be divided into two ecological types: shallow water lotus root and deep water lotus root. Shallow water lotus suitable for water level 10~20 cm, the maximum water depth of 30~50 cm. Deep water lotus is suitable for water level 30~50 cm, and the maximum water resistance depth is 1~1.2 meters.

The general principle of shallow water lotus layer management is: shallow before, medium deep, shallow after. During the germination period from planting lotus root to leaf emergence, shallow water should be kept to improve soil temperature and promote germination. It is generally good to maintain a water layer 4 to 7 cm deep. With the emergence of standing leaves, lotus stem and leaf growth gradually prosperous, water layer to gradually rise to 12~15 cm. When the termination leaves appear, it indicates that the lotus begins to form, and the water layer should be gradually reduced to 4~7 cm to promote the lotus formation. Deep water lotus water level is not easy to adjust, mainly to prevent flood season by waterlogging, especially after the vertical leaves submerged, should be in 8 hours emergency drainage, so that lotus leaves exposed to the water surface, in case of drowning. In the growth process of lotus root, especially in the early stage of shallow water lotus root growth, there are many weeds in paddy field, such as Potamogeton cristatum, Sagittarius pygmy, Trigonium trigonum, Azolla tetraphylla and Hydrilla, which grow rapidly and affect the growth of lotus root, so weeding should be carried out in time. In the past, manual cultivation and weeding were often used, with a large workload and easy to trample on the underground stems and buds of lotus roots. If chemical weeding is adopted, labor and effort are saved, and no harm is caused to lotus roots. Safe and effective methods of chemical weeding can be used. The specific methods are:

(1) Select 50% Veroxam emulsifiable concentrate, when the lotus root leaves grow 30 cm above the water surface, take 100 ml of medicine, mix 5 kg of urea first, add 5 kg of fine soil, mix well, and sprinkle in the field when the dew has dried. When applying the pesticide, the lotus root field is kept at a depth of 7 - 10 cm, and the water layer is kept for more than one week after the pesticide is applied, and the effect is good, and the residual effect period can reach more than one month.

(2) topdressing when lotus root grows to 50 cm. 50 kg of nitrogen, phosphorus and potassium compound fertilizer shall be applied per mu. Later found yellow leaves, can be applied once again urea, mu Shi 15 kg.

IV. Harvest and storage techniques of lotus roots

When harvesting, as long as you hold one end of the lotus branch and lift it upward along the growth direction, you can lift the whole lotus from the water, saving labor and effort. Also visible market conditions, generally after the end of August can be harvested.

Storage lotus root should be strictly selected without disease injury, solid texture lotus root meat hypertrophy, less water underground stem, not washed after harvest, the surface with mud whole storage. It can be stored indoors in shallow pits covered with straw or soil. or used for sand stratification in a storehouse, and the surface is covered with sand by 5 to 10 cm. The cover should not be too thin, otherwise the bulbs of the surface layer are easy to dehydrate and lose freshness. Humidity is too high, easy to root, mildew. According to the experiment, there is no obvious difference between dry sand burial in cold storage at 5~7℃ (maximum 11℃) and in ordinary basement (9~14℃ in winter and 23~25℃ in summer). The storage effect of plastic bags is not as good as sand burial, easy to mold, root, browning.