Detailed Explanation of Rice-Fish-Loach Ecological Agriculture Engineering Technology

1. Environmental conditions of the production area: a good ecological environment, far from pollution sources, good air; high, thick and compact paddy field ridges, relatively clayey soil, relatively high soil fertility, and paddy fields with sustainable development capacity; good irrigation and drainage conditions, relatively sufficient water sources, and fresh water quality.

2. Paddy field engineering facilities: dig a ring-shaped ditch around the paddy field, with a ditch width of 1 m and a depth of 0.5 m; surround the field ridges with anti-escape plastic sheeting (40-50 cm above ground, buried 20-30 cm underground); install double-layer anti-escape blocking nets at the water inlet and outlet.

3. Rice, river crab, @#@237@#@ variety selection: select rice varieties that have passed national or local approval and have been successfully demonstrated locally, with high quality, high yield and strong stress resistance; crab seed and loach seed must be high quality, robust, and uniform in size, with 160 juvenile crabs/kg and 130 loach seed/kg.

4. Rice seedling throwing density and stocking density of juvenile crabs and loach seed: throw seedlings (or transplant seedlings) at 16,000-17,000 hills per mu; 3-4 plants per hill for conventional rice, and 1-2 plants per hill for hybrid rice. Stock 450 juvenile crabs and 300-340 loach seed.

5. Stocking method for juvenile crabs and loach seed: 30 days after rice seedling throwing (15 days later for paddy fields not sealed with herbicide before seedling throwing), release the juvenile crabs and loach seed separately along the ring-shaped ditch into the paddy field; before release, soak them separately in a 3%-4% salt water solution for 5 minutes.

6. Irrigation: soak the field before rice seedling throwing; during seedling throwing, maintain a water layer of 5 cm in the field; from after seedling throwing to the tillering stage, maintain a water layer of 7-10 cm; from after tillering to before maturity, control the irrigation depth each time at 10-20 cm according to rice plant height; after the rice matures, drain and dry the field. Before releasing the juvenile crabs and loach seed, replace with fresh water twice; after release, replace with fresh water once every 3-5 days, with each water exchange amounting to 1/3-1/2 of the total field water volume.

7. Fertilization requirements: on the premise of applying sufficient base fertilizer, combine organic fertilizer with inorganic fertilizer, apply nitrogen, phosphorus and potassium in combination, and for topdressing follow "less each time, more frequently." The general ratio of nitrogen : phosphorus : potassium is 1:0.5:0.5. Pure nitrogen (N) per mu generally does not exceed 15 kg, and zinc sulfate 1-2 kg.

8. Drug use should implement the principle of "prevention first, integrated control." Advocate the use of cultivation measures, tillage measures, biological measures and ecological measures to control diseases, insect pests and weeds. Before rice seedling throwing, use low-toxicity, high-efficiency, residue-free herbicides for sealing (river crabs feed on weeds in the paddy field, so in paddy fields where the rice-crab-loach ecological agriculture model is promoted year after year, herbicide sealing is not needed before seedling throwing); after seedling throwing, do not use chemical agents. When pesticides must be used, choose low-toxicity, high-efficiency, residue-free pesticides and use foliar spraying methods; organophosphorus pesticides are strictly prohibited.

9. Bait feeding: after juvenile crabs are released into the paddy field, feed bait once a day in piles along the ring ditch, with the feeding amount at 5%-8% of the river crab body weight (increasing as the river crab body weight increases). Pair animal and plant bait; plant bait includes soybean cake (meal), peanut cake (meal), corn, @#@245@#@, sweet potato, potato and various aquatic plants; animal bait includes small miscellaneous fish, snails, river mussels, etc. Compound bait should meet the nutritional growth needs of river crabs.

10. Rice harvest and capture of river crabs and loach: after the rice matures, pollution-free rice and ordinary rice must be harvested and threshed separately; mixing in transport and storage with toxic, harmful, corrosive or odorous items is strictly prohibited; in early September, use loach baskets to catch loach; after September 10, use flowing-water capture, light trapping and silk net capture methods to catch river crabs.