Mixed farming of turtles and earthworms in the same pond yields high economic returns

Under micro-flowing water conditions, amphibious turtles and aquatic @#@254@#@ are co-cultured in one pond, with the aquatic earthworms serving as the main feed or supplementary feed for the turtles. This can make the turtles strong and healthy, grow faster, shorten the breeding cycle, reduce feeding costs, and more than double economic returns. Moreover, throughout the entire rearing process, contamination of the product by hormone drugs is avoided, meeting the basic requirements for pollution-free food and making it more popular with consumers. The main technical points are introduced as follows:

1. Pond construction

Choose a site with abundant water sources, good water quality, convenient irrigation and drainage, a quiet environment, and open, sunny conditions to build a rectangular breeding pond. The pond is 15 m to 30 m long, about 5 m wide, with walls 0.7 m high and a bottom slope of 0.5% to 1%. The length of the pond should follow the direction of water flow, and escape-prevention devices must be installed at both the inlet and outlet, both to prevent the turtles from escaping and to prevent entry by predators. To avoid dead corners in the water flow, the four corners of the pond are best made curved. If the length is insufficient and it is not suitable to build a rectangular pond, a ring-shaped or meandering-flow pond can also be built.

In the pond, rectangular soil ridges are piled up. The ridge length depends on the pond width, the ridge width is about 1.5 m, and the ridge height is 0.25 m to 0.3 m. The spacing between ridges and between ridges and the pond walls must not be less than 0.2 m to prevent entry by predators. For the soil material of the ridges, farm fertile mud, silt, and other soil materials rich in organic matter should be selected as much as possible to facilitate the rapid growth and reproduction of earthworms. On one side of the pond or along the inner edge of a ring-shaped pond, a gentle-slope soil mound 0.3 m to 0.8 m above the water surface is piled up as a resting and egg-laying site for the turtles, with an area of 15% to 20% of the total area. Grapes, loofah, or other vine crops are planted around the pond, and a trellis is set up overhead to form a shaded environment, which can be manually adjusted to achieve the optimal shading state.

2. Cultivation of earthworm substrate

Fill the pond with water until it floods the ridge surface. On the ridge surface, first spread a layer of bagasse or chopped straw, fallen leaves, etc. as a loosening agent, at 2 kg per sq m. On top of that, spread cow dung or a mixture of pig, sheep, and chicken manure. Then sprinkle about 0.2 kg per sq m of fully fermented corn flour and a mixture of rice bran and wheat bran. Where conditions are poor, a cow dung layer alone may be used, or a mixed material of cow dung, pig manure, sheep manure, and chicken manure may be spread.

3. Introduction and breeding of earthworms

After the manure on the ridge surface has fully fermented for about 10 days, when the temperature is 25°C to 28°C, seed earthworms can be introduced. Generally, it is best to choose Japanese Daping No. 2. Put 2.5 kg per sq m of seed earthworms with feed and egg capsules, and evenly scatter them on the surface of the substrate. If Daping No. 2 seed earthworms are unavailable, they can be introduced from other earthworm farms, or aquatic earthworms already adapted to an aquatic environment can be collected nearby from sewage ditches, pools, and other places together with egg capsules, mud residue, etc., and spread on the ridge surface to let them grow and reproduce on their own. It must be noted that in breeding ponds where aquatic earthworms are introduced, the water level should be equal to the substrate surface or slightly higher than the substrate surface by 1 cm to 2 cm.

Earthworms are accustomed to a slightly acidic environment with a pH of 5.5 to 7.8, and especially like palatable feed with a sweet-and-sour taste. Whether grains, livestock and poultry manure, domestic sewage, organic waste, or slaughtering and processing waste, all are high-quality feed sources for them. However, any feed must first be fermented and decomposed before feeding; otherwise, during its fermentation or secondary fermentation, a high temperature of about 80°C will kill young earthworms and egg capsules.

After the earthworms are introduced for 5 days to 7 days, they can eat the feed on the surface layer. The surface waste containing most fecal pellets should be scraped off and applied as organic fertilizer, and another 5 kg of fermented cow dung per sq m should be scattered. From 15 days to 20 days after introduction, the earthworms have already reproduced in large numbers, and turtles can then be stocked for rearing.

4. Stocking and management of turtles

Stocking density: based on the total pond area, 30 one-winter-old juvenile turtles per sq m can be stocked, or 15 two-winter-old young turtles, or 3 to 5 adult turtles of three winters or more. It should be noted that those with large individual differences should be stocked separately in different ponds according to size, so as to avoid losses caused by the big bullying the small, biting and fighting, causing injury or even disability. Before the turtles are put into the pond, they should be disinfected and sterilized with 8% to 10% salt water to prevent disease.

Water quality management: industrial wastewater and poisonous medicinal water used for treating fish diseases or killing insects in rice fields are strictly forbidden from entering the pond; otherwise, major losses will be caused. Apart from temporarily closing the inlet and outlet when changing water, the breeding pond should maintain a micro-flowing water state with a flow rate of 0.01 cubic meters per second for a long time, so as to meet the relatively low oxygen demand of the turtles and earthworms.

Feeding management: whether the earthworms are the staple food or supplementary feed for the turtles, simply let them feed on their own. Just take care not to let them gather unevenly in one place to compete for food and bite and fight, causing injury or disability. Generally, no great effort is needed for management.

Whether fresh earthworms or dried earthworms, their crude protein content is relatively high, among which the amino acid content reaches 35.2% (on a dry matter basis), so they are a high-quality high-protein feed for aquatic animals such as turtles and soft-shelled turtles, as well as livestock and poultry. According to comparative experiments on co-culturing aquatic earthworms as feed in turtle and soft-shelled turtle ponds, the turtle yield of the experimental group increased by 36.4% compared with the control group, and the effect was very obvious.