Planting techniques of aquatic plants in lobster ponds

Planting aquatic plants in crayfish ponds should adhere to the principle of "uniform distribution, matching of species and appropriate density" to meet the needs of crayfish habitat, feeding, growth and reproduction. There is a well-shaped planting in the middle of the pond and a mouth-shaped planting along the water level line of 1 meter around the pond. The planting point of aquatic plants can not be too dense to ensure the lobster's normal life and smooth swimming channel. It is appropriate to plant verticillium verticillata and water peanuts in the middle of the pond, and it is better to plant Ellosia and bitter grass around the pond. The coverage density of aquatic plants should be controlled at about 60% of the total area of shrimp ponds, which should be removed manually when it is too much, and should be replenished in time when it is insufficient.

Variety selection of aquatic plants

There are mainly three types of aquatic plants planted in crayfish ponds: submerged plants, floating plants and standing plants, which are generally dominated by submerged plants and floating plants, supplemented by water plants. The main varieties of submerged plants are Elodea, bitter grass, Potamogeton crispus, Elaeagnus angustifolia, goldfish algae, etc., while the main varieties of floating plants are water peanut, water hyacinth, water lotus, duckweed and so on. The main varieties of water plants are: Reed, Zizania caduciflora, Sagittaria angustifolia, cattail and so on.

The planting function of aquatic plants

1. Aquatic plants are the nutritional source of crayfish. Aquatic plant has the characteristics of fresh, tender, crisp and slippery, which is in line with the natural eating habits of crayfish. It is a favorite plant bait for crayfish and plays an important role in the food composition of crayfish. Protein, fat, cellulose, vitamins, calcium and phosphorus contained in aquatic plants are the guarantee of balanced nutrition of bait. Crayfish often eat aquatic plants, which can promote digestion, reduce morbidity and is very beneficial to its healthy growth. At the same time, places with dense aquatic plants can also attract many bait creatures such as screws and small fish for crayfish to eat.

2. Aquatic plants are the habitat, feeding and hiding place of crayfish. The swimming ability of crayfish is weak, so it can only take a short swim in the water, crawl on the floating leaves of aquatic plants at night to rest and play, climb to feed on aquatic plants during the day, and the body is exposed to sunlight, which can promote the absorption of calcium and is conducive to the development and growth of carapace. At the same time, it can also reduce the harm of body surface parasites. The periodic shelling of crayfish is often attached to the stems and leaves of aquatic plants, and the soft-shell shrimp after shelling can hide in the water plants, so it is not easy to be found by hard-shell shrimp and other fish or enemies, thus avoiding the possibility of being eaten by remnants and improving the survival rate of soft-shell shrimp. In the high temperature season, crayfish can hide with the help of aquatic plants to cover the sun and cool, reduce the number of holes and improve the recapture rate.

3. Aquatic plants can purify the water quality and improve the sediment. Aquatic plants can release a large amount of oxygen through plant photosynthesis, absorb ammonia nitrogen, carbon dioxide, residual bait and some organic decomposition products produced in the water, keep the pH value in the range of neutral alkali, and increase the transparency of the water body. it plays a role in purifying and stabilizing water quality. When the residual bait is deposited at the bottom of the pond, the water quality is easy to become fat, which does great harm to the growth of crayfish and is more likely to lead to shrimp disease. The metabolic function of aquatic plants can absorb ammonia nitrogen and inorganic salts in silt and play a role in improving the sediment of shrimp ponds.

Planting methods of aquatic plants

The main results are as follows: 1. Transplanting method: verticillum verticillata, Eloe algae and other stemmed aquatic plants are suitable for transplanting, and generally choose to be planted in winter and spring. The method is to cut the aquatic plants into small sections, with a length of 15 cm to 20 cm. Like transplanting rice seedlings, the bundles of cut grasses are evenly planted in the mud at the bottom of the pool, and the plant and row spacing are controlled at about 20 cm respectively. After planting, inject 20-30cm water into the shrimp pond and gradually deepen the water level after the water plants grow all over the pond.

2. Throwing planting method: floating-leaf plants such as lotus and water lilies can be wrapped in soft mud and then directly thrown into the pond so that their rhizomes can grow in the sediment and let their leaves float on the surface of the water.

3, transplanting method: Zizania caduciflora, Zizania latifolia and other water-bearing plants should be transplanted by roots. when transplanting, the injured leaves and slender and shoddy seedlings should be removed, and the transplanting location can be in the shoal on the edge of the pool, requiring that the root of the seedlings should enter water between 10 and 20 centimeters, and the density should be controlled at 30 to 50 ∕ 667m2.

4. Cultivation method: for floating plants such as water peanuts, water hyacinth and duckweed, bamboo poles and grass ropes can be used in the pond as a "special zone" for intensive cultivation, so that the above-mentioned aquatic plants can grow and reproduce in the "special zone" environment. As a supplement when there is a shortage of water plants in shrimp ponds.

5. Sowing method: the most commonly used aquatic grass is Sophora flavescens. The sowing method of bitter grass is suitable for shrimp ponds with less silt. Soak the bitter grass seed in water for 1 day, then crush the soft fruit, rub out the fine seeds in the fruit, add about 10 times the amount of fine sand, mix well with the seeds before sowing. When sowing, the water level is controlled at 10-20 cm, and the sowing rate is about 50 grams per 667 square meters. After sowing, the management should be strengthened to improve the survival rate of Sophora flavescens so as to form a dominant population as soon as possible.