Selenium-rich fish, turtle and soft-shelled turtle ecological polyculture method based on livestock and poultry manure-earthworms-selenium-rich azolla filliculoidas

Abstract

The invention relates to a selenium-rich fish, turtle and soft-shelled turtle ecological polyculture method based on livestock and poultry manure, earthworms and selenium-rich azolla filliculoidas, and belongs to the technical field of aquaculture. Through a three-level selenium enrichment technology (wormcast selenium 14-15 mg / kg, rumex hanus 1.4-1.5 mg / kg and feed 60% selenium-rich rumex hanus) and a spatial layered polyculture mode (upper-layer crucian, middle-layer turtles and bottom-layer turtles), the yield per mu is larger than 1335 kg, the selenium content of crucian is 0.12 mg / kg, the selenium content of turtles is 0.35 mg / kg, the selenium content of turtles is 0.33 mg / kg, the yield is increased by 12% compared with that of traditional single culture, and the feed cost is reduced to 1.1 yuan / kg. The water quality (ammonia nitrogen is less than 0.3 mg / L) is regulated and controlled by adopting a complex microbial inoculant, and facilities such as a back sunning platform and an inhabiting cave are matched, so that the survival rate reaches 85-90%.

Description

Technical Field

[0001] The present invention belongs to the field of aquaculture technology (IPC classification number A01K 61 / 00), and specifically relates to a comprehensive production method that realizes the ecological polyculture of fish, turtles, and soft-shelled turtles and improves the organic selenium content of products by resource utilization of livestock and poultry manure, combined with earthworm biotransformation and selenium-rich Rumex patientia L. cultivation. Background Art

[0002] The traditional single-culture mode has the following defects: 1. Single-culture of turtles and soft-shelled turtles (CN114521346B): The yield per mu is only 300 - 350 kg, and the selenium content is less than 0.15 mg / kg, which cannot meet the selenium-rich standard of NY / T 841 - 2017; 2. High-density single-culture of fish: The feed cost accounts for more than 60%, and the residual bait causes the ammonia nitrogen concentration in the water body to be > 1.5 mg / L, and the disease incidence rate increases by 30%; Innovation of the present invention: ① Initiated a four-level material cycle system of "livestock and poultry manure → earthworms → Rumex patientia L. → fish, turtles, and soft-shelled turtles", and the selenium enrichment efficiency is 5 times higher than that of the traditional biological chain; ② Through the ecological niche complementarity of crucian carp filtering algae and turtles and soft-shelled turtles feeding on residual bait, the feed coefficient is reduced by 0.8, and the water change frequency is reduced by 50%. Summary of the Invention

[0003] The spatial hierarchical design makes full use of the vertical space of the water body: Crucian carp (upper layer): Filter plankton and inhibit excessive algae reproduction; Turtle (middle layer): Sunbathe to adjust body temperature, prey on sick and weak fish, and remove residual bait at the bottom of the pond; Soft-shelled turtle (bottom layer): Sunbathe to adjust body temperature, prey on sick and weak fish, and remove residual bait at the bottom of the pond.

[0004] The three form an ecological balance. With the feeding of selenium-rich feed, the organic selenium content of the final product is increased by 2 - 3 times compared with conventional aquaculture. Specific Embodiments Example 1: Large-scale aquaculture in the north (Shandong region) 1. Site construction and facility configuration Pond specifications: 10 mu of contiguous ponds, running east-west, with a bottom slope of 1:3, and 20 cm thick loess (pH 6.8 - 7.2) laid on the bottom of the pond; Oxygenation system: One 1.5 kW impeller aerator is configured for every 2 mu, and it operates for 2 hours each at 4 - 6 am and 14 - 16 pm every day; Anti-escape facilities: 60 cm high calcium plastic boards are installed around the pond (buried 20 cm underground), and a 15 cm inwardly folded eaves is added on the top.

[0006] 2. Preparation process of earthworm manure Raw material pretreatment: Cattle and sheep manure: Stacked and fermented for 7 days (temperature ≥ 55 °C) to kill parasite eggs; Corn straw: Crushed into 2 - 3 cm segments and soaked in 3% lime water for 24 h to soften; Fermentation parameters: Mixing ratio: Cattle and sheep manure : straw : sodium selenite = 3 : 1 : 0.001 (i.e., 3 tons of manure + 1 ton of straw + 1 kg of sodium selenite); Inoculation amount: The cold - tolerant earthworm strain Qiu - B - 01 is inoculated at 5% of the total weight of the raw materials; Temperature control: There are floor heating pipes in the fermentation tank to maintain a temperature of 22 - 25 °C and a humidity of 60% - 70%; Product detection: Samples are taken on the 45th day. The selenium content in the earthworm manure is 15.2 mg / kg (ICP - MS method), and the organic matter content is ≥ 35%.

[0007] 3. Planting management of selenium - rich Rumex patientia Sowing: Drill - sow in mid - April, row spacing is 40 cm, seeding rate per mu is 1.5 kg, and cover with 2 cm of earthworm manure after sowing; Water and fertilizer management: Base fertilizer: 600 kg / mu of earthworm manure, mixed in when plowing deeply by 30 cm; Top dressing: Apply 200 kg / mu of earthworm manure liquid (diluted 1:10 with water) after each harvest; Harvesting: Harvest once every 25 days during the growth period, leaving a stubble height of 5 cm; Dry at 60 °C until the moisture content ≤ 12%, crush and sieve through a 40 - mesh sieve for standby.

[0008] 4. Detailed rules for polyculture management Stocking operation: Species, stocking time, disinfection treatment, water - testing method Crucian carp, May 10th, soak in 3% brine for 10 minutes, first release 20 tails and observe the survival for 24 hours Turtle, May 20th, medicate in 5 mg / L povidone - iodine solution for 15 minutes, transfer after adapting in the temporary culture pond for 3 days Soft - shelled turtle, May 25th, soak in 2 mg / L potassium permanganate solution for 30 minutes, slowly release into the pond along the slope of the pond edge Feeding strategy: Feed formula: 60% selenium - rich Rumex patientia powder + 20% earthworm powder + 15% corn flour + 5% premix; Feeding frequency: From June to September: Feed once at 7:00 and 17:00 every day, feeding rate is 4%; Other months: Feed once at 11:00 every day, and the feeding rate is 2%. Calcium supplementation measures: Put 30 kg / mu of live Pomacea canaliculata into the pond every half month, concentrated around the basking platform.

[0009] 5. Water quality and disease monitoring Water quality regulation: Sprinkle compound bacterial agents (photosynthetic bacteria: bacillus subtilis = 1:1) at 3 g / m³ every Tuesday and Friday; Change the water once at the end of each month, with a water change rate of 20%-30%, and the temperature difference before and after water change ≤ 2°C; Disease prevention and control: Mix allicin (0.5 g / kg feed) into the feed and feed continuously for 3 days every 20 days; When saprodermatitis is found, sprinkle the extract of Chinese gallnut (final concentration 2 mg / L) throughout the pond.

[0010] 6. Output data Index, measured value, detection standard Selenium content in turtles, 0.35 mg / kg, GB 5009.93-2017 Selenium content in soft-shelled turtles, 0.34 mg / kg, GB / T 35876-2018 Average yield per mu, 1335 kg (±5%), actual weighing Feed coefficient, 1.8, total feeding amount / total weight gain Water ammonia nitrogen, 0.28 mg / L (continuous monitoring), HJ 535-2009 Example 2: Aquaculture by farmers in the south (Guangdong region) 1. Transformed courtyard aquaculture system Facility layout: Use 0.8 mu of paddy field for reconstruction, raise the ridge to 1.2 m, the water depth on the field surface is 0.8 m, and keep 10 cm thick silt at the bottom of the pond; Zoning design: The edible leaf grass planting area (0.2 mu) and the aquaculture area (0.6 mu) are separated by bamboo fences; Ecological floating bed: Set up a 30㎡ bamboo floating bed on the water surface of the aquaculture area to plant water spinach (absorb excess nitrogen and phosphorus).

[0011] 2. Low-cost vermicomposting technology Composting box: Drill holes in the waste plastic box (60 cm × 40 cm × 30 cm) for ventilation, and pad 5 cm of gravel at the bottom; Raw material ratio: Fresh pig manure: rice husk: sodium selenite = 3:1:0.0008 (reduce selenium dosage to prevent accumulation); Fermentation management: Turn the pile once every 7 days, and spray well water to cool down when the temperature exceeds 30°C; After 45 days, the selenium content in earthworm manure is 14.3 mg / kg, which is directly used for topdressing of Rumex patientia L..

[0012] 3. Adaptive management measures Response to high temperature: Cover with a sunshade net with a shading rate of 70% from 11:00 to 15:00 every day in summer; The coverage area of floating water hyacinths on the water surface ≤ 20%; Protection against heavy rain: Dig a drainage ditch with a width of 40 cm and a depth of 60 cm around the pond, and fill the ditch with gravel; Add zeolite powder (10 kg / mu) before heavy rain to adsorb toxic substances.

[0013] 4. Recycling mode Material flow design: Pig manure --> Earthworm compost --> Rumex patientia L. planting --> Grass powder feed Aquaculture wastewater --> Sedimentation tank --> Aquatic vegetable irrigation The shell of Pomacea canaliculata --> After being crushed, it is used as a calcium source for soft-shelled turtles 5. Records of solving typical problems Problem: Soft-shell disease appears in turtles in July Measures: ① Immediately increase the feeding of Pomacea canaliculata to 50 kg / mu; ② Add 2% bone meal + 0.1% vitamin D3 to the feed; ③ Increase the number of basking platforms to 15 per mu; Result: The symptoms disappeared after 10 days, and no deaths occurred.

[0014] Clarify the disinfection concentration (3% brine), topdressing ratio (1:10 manure liquid), and detection frequency (change water at the end of each month); 6. Risk prevention and control plan Disease prevention and control: Add 0.5 g / kg of astragalus polysaccharide to the feed every month to prevent skin ulcer disease.

[0015] Selenium stability control: After harvesting Rumex patientia L., it is dried at a low temperature of 60 °C, and the selenium loss rate < 5%.

Claims

1. A method for ecological polyculture of selenium-enriched fish, turtles and tortoises, characterized in that The following steps are involved: (1) Spatial hierarchical configuration: ① Crucian carp are cultured in the upper layer, with a density of 3,000 per mu, an initial size of 50-100g per carp, and a water depth of 1.5m; ② For the middle layer, the density is 200 turtles / mu, the initial size is 50-80g / turtle, 10 basking platforms are set up / mu, and the height of the basking platforms above the water surface is 15cm; ③ Bottom-layer turtle farming, density 150 per mu, initial size 80-120g per turtle, 5 habitat caves per mu; (2) Selenium content control: achieved through a three-level selenium enrichment system: ① Primary enrichment: livestock and poultry manure, straw and sodium selenite are mixed at a ratio of 3:1:0.001, inoculated with earthworm strains and fermented for 45 days to obtain earthworm manure with a selenium content of 14-15 mg / kg; ② Secondary enrichment: Plant leaf-eating grass with earthworm manure as base fertilizer to make the selenium content of leaf-eating grass reach 1.4-1.5 mg / kg; ③ Level 3 enrichment: Selenium-rich leafy grass, earthworm powder and corn powder are made into feed in a ratio of 6:2:2, and the daily feeding amount is 2%-4% of the total weight of the cultured organisms; (3) Water quality control: Add 3g / m³ of photosynthetic bacteria and Bacillus complex agent every week to maintain ammonia nitrogen <0.3mg / L and dissolved oxygen ≥5mg / L.

2. The method according to claim 1, characterized in that: The earthworm strain is cold-resistant Qiu-B-01 or heat-resistant Qiu-N-01, the fermentation temperature is 22-28° C., and the earthworm castings protein content is ≥20%.

3. The method according to claim 1, characterized in that: In turtle farming, 200kg / mu of golden apple snails are supplemented as a calcium source.