The main technical measures are as follows:
I. Pond construction
You can use a ready-made lotus pond, or you can build a new lotus pond. It is better to breed in a water mud pond if conditions permit. After the new pond is completed, it can be dug to 1 10cm, and the bottom and wall of the pond are made of cement bricks and plastered with cement. The wall of the pool is 20-30 cm above the ground, and the top is equipped with a T-shaped pressure mouth or is lined with tiles to prevent escape. Both ends are provided with water inlet, drainage and overflow ports, and each port is provided with a dense mesh net. The bottom of the pond is paved with grass roots or leaves for about 30 cm. In order to facilitate leeches to perch and lay eggs, a soil platform 20cm above the water surface should be built in the middle of the pool, with 5- 10 per mu, and each platform is about 1 square meter.
Before injecting water into the pond, proper amount of decomposed livestock manure and chemical fertilizer should be applied to the soil as the base fertilizer, and the amount of fertilization should be less than that of the common lotus pond, not too much. 300-800 kg of common fertilizer, 7- 15 kg of urea and 20-35 kg of calcium superphosphate. There is no need to fertilize again in the future, so that lotus roots can grow naturally.
Deciduous trees should not be planted around the pond to prevent a large number of leaves from falling into the pond in autumn, polluting the pond and causing leeches to die.
Second, seed placement.
1, lotus root planting
Generally, lotus roots can be planted after first frost in spring. The planting density is thinner than that of the common lotus pond. The plant spacing is 2m×2.5m, about 130 holes are planted per mu, and about 130-230kg of lotus seeds are needed per mu. Water should be injected after planting. Within 15 days, the water should be shallow and the water layer should be kept about 6cm, which can increase the soil temperature and promote germination, and then gradually deepen the water layer. About 20-25 days after planting, when there are 1-2 leaves, the water level can be deepened to 20cm, and leeches can be raised. Then gradually deepen the water level to 60cm.
2. Leech socks
Leeches can be introduced from other farms, or they can be caught as seeds from the wild. When introduced, leeches over 2 years old and weighing 10-30g should be selected as seed leeches. Leech should be strong, lively and active, and quickly shrink into a ball when touched by hand. It is best to put about 20kg leeches per mu of water surface, and the stocking specifications should be as uniform as possible. Different leeches should be kept in different ponds to avoid the law of the jungle.
Third, feeding management.
In the process of feeding management, it is necessary to strengthen feeding management, water quality regulation, escape prevention, reproduction, pest control and overwintering management.
1, feeding
Leeches mostly feed on blood or body fluids. Fresh blood clots of various livestock and poultry, grass shrimp, snails, mussels, snails, earthworms and insect larvae can all be used as bait for leeches. Animal blood can be fed/kloc-0 times a week, about 7.5kg per mu. Put the blood clots of pigs, cows, sheep and other animals into the pool, and put them every 5 meters 1 block. After leeches are fully absorbed and dispersed, remove residues in time to avoid polluting water quality. If you see most leeches swimming in the water, it means that the bait in the pool is insufficient, so you should immediately replenish the material and feed snails, earthworms, insects and so on.
2. Water quality regulation
During the feeding process, the water quality should always be fresh and not polluted, especially when the temperature is high in July and August, attention should be paid to changing the water. The water temperature should be between 15 -30℃, lower than 10℃ or higher than 30℃ is not conducive to the growth of leeches, and leeches stop eating when the temperature is low.
Some duckweeds or aquatic plants can be properly put in the pond, which can provide activities and habitats for leeches. At ordinary times, sundries should be prevented from falling into the pool. If there are sundries, they should be removed immediately to prevent water pollution.
3. Escape prevention
Leeches generally don't escape across the pool in sunny days, but they will escape with the running water when the pool overflows in rainy days, so it is necessary to set up a dense mesh fence according to the water level before the rainy season. At ordinary times, it is necessary to regularly check the escape prevention facilities such as the escape prevention net at the water inlet, water outlet and overflow port, and repair them in time if they are damaged to prevent leeches from escaping.
4, breeding period management
The mating time of leeches is May to September every year, and the spawning period of leeches is 6-65438+1October. At this time, we should keep the environment quiet, try to avoid walking and vibration by the pool, and prevent leeches from escaping from shock and causing empty cocoons. After the leeches are cocooned, they can be caught in another pond for feeding or processing, and the cocoons are left in the pond to hatch naturally. Young leeches hatch about 1 1-25 days after cocoon emergence, and they mainly rely on yolk to maintain their life within 2-3 days after hatching, and they can eat after 3 days. At this time, young snails, snails and mussels can be put in for feeding. After about 20 days, when the young leeches grow to more than 1.5cm, they can be transferred to large ponds for culture, and they can grow up in 270-300 days.
5, pest control
Mainly to prevent the pollution of pesticides, especially organophosphorus and organochlorine pesticides, which may cause leech poisoning and even death, easily accumulate in leech, reduce the quality of medicinal materials and harm human body. Therefore, highly toxic organophosphorus and organochlorine pesticides should not be used in lotus roots and crops around ponds.
The second is to prevent natural enemies from entering. Such as waterfowl, mullet, eel and frog. , should be wiped out. It is worth noting that leeches must not be mixed with toads, because toads will prey on leeches, and leeches will hurt toad eggs and tadpoles, which is not good for both sides.
Step 6 Overwintering
After winter, leeches burrow into the soil to hibernate. At this time, the leeches raised in the early days have generally grown up and can be captured, processed and sold. When fishing, choose large and healthy seeds, each mu 15-20kg seeds, and put them in the breeding pond for the winter. When overwintering, the pond water can be drained, covered with straw to keep warm, or deepened to prevent the pond water from freezing to the end, so that leeches can safely overwinter.