How to do soil-free ecological farming of rice field eels and loaches? Detailed explanation of the aquaponics startup project

Nanjing YIWEIYI Biotechnology Co., Ltd. now holds training courses every month on ecological farming technology for rice field eels and loaches, training returnee entrepreneurs in efficient ecological farming agriculture. The company's technical directorZhou Wenzongholds a Ph.D. and is a renowned expert and scholar in China's ecological farming field, with dual doctorates in ecological engineering and aquatic biology. He has led and completed 24 provincial-level research projects, participated in 11 projects including the "10th Five-Year Plan" National Major Science and Technology Special Project, the National Science and Technology Tackling Program, the 863 Program, and provincial-level projects, and holds 7 national invention patents as the first inventor. After more than twenty years of scientific research, he has achieved ten major technological innovations in the ecological farming field. In recent years, he has broken through traditional farming methods and pioneered four core technological innovations: "soil-free rice field eel farming in aquaculture membrane ponds," "soil-free loach farming in aquaculture membrane ponds," "overwintering and early stocking of rice field eels in net cages," and "co-cultivation of rice field eels and loaches with vegetables and fruits in the same pond." In line with the principle of "train one household, succeed one household, drive one township, benefit one county," the company uses intensive technical training as the foundation, base internships as the method, follow-up services as the link, and the pharmaceutical and feed industry chain as support to vigorously develop the loach ecological circular farming industry.
I. Four Major Innovation Achievements in the Ecological Farming Field
Achievement 1: Still-water soil-free rice field eel farming technology in impermeable membrane ponds
Features of the impermeable membrane pond rice field eel farming method: (1) It solves the problems of net cages being unable to overwinter and large water surfaces being difficult to manage; (2) The pond construction cost is half that of a cement pond; one person can complete the construction of one membrane pond in 1 day (digging the pond, installing inlet and outlet ports, laying the membrane); (3) The high-quality polyethylene virgin resin impermeable membrane is produced with Italian equipment and American standards, non-toxic and environmentally friendly, and fast to install. It has high mechanical strength, good chemical stability, resistance to plant root penetration, high impermeability coefficient, anti-aging, UV resistance, strong decomposition resistance, good plasticity, and a guaranteed service life of eight years; (4) The pond is easy to observe, water changes and sludge removal are thorough, and the water body has a long shelf life; spraying liquid medicine leaves no dead corners, and the disease prevention effect is good; winter water temperature is higher than in cement ponds, which helps extend the feeding period of rice field eels and loaches; (5) Harvesting can "catch everything in one net," with no missed catches; (6) The pond walls are smooth and will not cause damage to the mucous membrane on the fish body surface, reducing the occurrence of fish diseases; (7) It has the best land reclamation properties; (8) The pond does not require dealkalization or disinfection.

Achievement 2: Soil-free loach farming technology in impermeable membrane ponds
Traditional pond net-enclosure soil-based loach farming yields only two to three hundred kilograms per mu, and because loaches have smooth, rounded bodies and a habit of burrowing into mud, harvesting is quite difficult, the recapture rate is not high, and yield and profitability are affected. In contrast, impermeable membrane ponds combined with net-cage soil-free loach farming extend the loach growth period, making production possible year-round. It also features high stocking density, flexible selection of water areas for net cage placement, high per-unit yield, convenient management, a 100% recapture rate, and convenient overwintering, making it an intensive farming method.

Achievement 3: Overwintering and early stocking technology for rice field eels in net cages
Rice field eel stocking is usually concentrated from late June to the end of July (stocking too early means unstable temperatures, and rice field eels are in their peak breeding period, resulting in low survival rates). The supply shortage situation causes seed prices to soar. In recent years, Zhou Wenzong invented early stocking technology, allowing stocking in all four seasons (April, May, August, September, etc.). Seedlings purchased in April cost only about ten yuan, and by the end of June during the peak stocking period, they can sell for over 20 yuan. Early stocking technology extends the growth cycle, increases the weight gain multiple, and solves the overwintering problem.

Achievement 4: "Aquaponics" technology for rice field eel and loach farming ponds
Water hyacinth grown on the water surface of rice field eel ponds does have a water quality regulation function, but it has the problem of growing rampantly and competing with the eels for space. In an aquaponics system, vegetables can absorb nutrient salts such as nitrogen and phosphorus discharged from fish metabolism in the farming water, removing 80-90% of suspended matter and 70-80% of organic matter, reducing biological oxygen demand by 90-95%, and can keep the water pH within the standard range. Plant bactericides secreted by the roots of aquatic vegetables can kill 90-95% of pathogenic bacteria, giving the pond water body self-repairing capability. The complete compound feed used in this system contains ingredients such as fishmeal and bone meal, which precisely supplement the trace elements needed for vegetable growth. The vegetables currently successfully cultivated are water spinach, water dropwort, lettuce, tomato, strawberry, and cherry tomato. This increases profitability and avoids the rampant growth of water hyacinth.

II. Investment Benefit Analysis
Economic targets of the mature technology: survival rate 90-95%, economic input-output ratio 1.9:1, cost profit margin 90.9%. If earthworms and sterile maggots raised on organic waste, or live bait such as miscellaneous fish and livestock and poultry scraps, are added to the feed (3 jin of feed can be mixed with 1 jin of small miscellaneous fish. Feed is primary, live bait is supplementary, and must not exceed 1/2), feed costs can be reduced by 1/3 to 1/2.
(1) Investment benefit analysis of soil-free rice field eel farming in impermeable membrane ponds
(1) Pond construction cost (depreciated over 8 years of service life): 40 yuan / 8 years = 5 yuan/year; (2) Seedlings: 30 yuan/kg x 1.5kg/sq m = 45 yuan/sq m; (3) Feed: 3.5kg/sq m x 2 (feed conversion ratio) x 8 yuan/kg = 56 yuan/sq m; (4) Fish medicine: 2 yuan/sq m; (5) Labor cost: 100,000 yuan/person / 2,000 sq m = 5 yuan/sq m; (6) Water, electricity and other costs: 3 yuan/sq m; Total: 116 yuan/year per sq m.
Calculated on the basis of each 20 sq m eel pond, production cost: 2,320 yuan/year (of which: pond construction cost 100 yuan, seedling investment 900 yuan, feed cost 1,120 yuan, medicine cost 40 yuan, labor cost 100 yuan, water, electricity and other costs 60 yuan); product income: 4,200 yuan/year per pond. Net profit: 1,880 yuan/year per pond. (Excluding the field ridges between ponds, 500 sq m of eel ponds are actually built per mu, 25 ponds.)

(2) Investment benefit analysis of soil-free loach farming in impermeable membrane ponds
Calculated on the basis of 11 ponds, 1 standard roll of farming impermeable membrane (420 sq m) is needed, each pond is 20 sq m, totaling 220 sq m.
1. Fixed investment (depreciated over 8 years)
(1) Membrane: 3,300 yuan; (2) Water pipes and supporting facilities: 800 yuan; (3) Labor cost: 800 yuan; (3) Greenhouse: 6,000 yuan. The above total after depreciation: 1,360 yuan/year.
2. Working capital
(1) Seedlings: 250 kg x 30 yuan/kg = 7,500 yuan; (2) Feed: 500 kg x 3.5 x 4 yuan/kg = 7,000 yuan; (3) Medicine and water and electricity costs: 200 yuan, total above: 14,700 yuan.
Fixed investment and working capital total: 16,060 yuan.
3. Production benefits
Calculated for only one season (generally two seasons can be farmed per year in greenhouses):
Producing 750 kg of loach, sold at 30 yuan/kg, the 11 farming ponds generate 22,500 yuan in income, with a net profit of 6,440 yuan. In addition, the profit from vegetables co-cultivated in the same pond is 1,000 yuan, for a total net profit of 7,440 yuan. The profit per sq m is approximately 34 yuan, equivalent to a profit of 22,540 yuan per mu, with a profit margin of 45%.
(The above does not include income from aquatic vegetables. Different vegetables can be planted according to the season each year; five to six harvests of fresh vegetables can be obtained per season, increasing income by several thousand jin of vegetables per mu, and reducing water change costs by several hundred yuan per mu. If the aquatic vegetable varieties and layout are reasonable, fish medicine costs are also reduced.)

III. Rice Field Eel and Loach Ecological Farming Entrepreneurship Training Content
1. Training subjects
(1) "Rice Field Eel Ecological Farming Technology" (net cage farming; soil-free membrane pond farming; overwintering and early stocking technology; brief introduction to semi-artificial breeding technology); (2) "Loach Ecological Farming Technology" (pond net-enclosure soil-based farming; net cage farming; soil-free membrane pond farming; cement pond soil-based farming; rice paddy farming; biogas fertilizer farming; methods to increase loach growth rate; brief introduction to artificial breeding and seedling rearing); (3) "High-efficiency High-yield Bait Cultivation Technology" (earthworms, sterile housefly maggots, yellow mealworms, red worms, etc.); (4) "Water Quality Regulation and 'Aquaponics' High-yield Technology."

2. Follow-up technical services enjoyed by trainees
The company guarantees supply through the industry chain of "seedling supply + feed supply + fishery medicine supply + impermeable membrane supply," increasing the safety factor of trainees' entrepreneurship: trainees can enjoy preferential prices on specialized aquaculture membranes, seedlings, fish medicine and specialized compound feed, receive long-term free technical consultation services, and obtain free follow-up technology for the projects they were trained in. Technical consultation: 025-84825782