Nghe An prepares for shrimp farming crop 1
(Baonghean.vn) - In 2021, Nghe An strives to have an aquaculture area of 21,420 hectares, of which freshwater farming area is 18,870 hectares; brackish water farming area is 2,550 hectares (shrimp 2,280 hectares); aquaculture output is 59,000 tons, of which freshwater farming output is 46,500 tons, brackish water farming output is 12,500 tons (of which shrimp is 7,800 tons).
To achieve the above goal, at the beginning of the year, the Department of Agriculture and Rural Development announced the 2021 aquaculture season schedule. Accordingly, for black tiger shrimp seed production, the seed production period is from February 3 to July 21, 2021. Seed production and rearingwhite leg shrimpfrom 3/2 - 30/10/2021.
For white-leg shrimp farming, the main crop is released from April 5 to June 30, 2020; density is 80 - 150 shrimp/m2; shrimp seed size P12 (for farming facilities with infrastructure conditions to ensure nursery, shrimp seed can be nursed in ponds or tanks for 20 - 25 days before stocking).
Winter crop: Release from September 1 - October 30, 2021; density 70 - 120 fish/m2; shrimp seed size P12; only applies to independent shrimp farming areas, infrastructure conditions and water environment ensure technical requirements.
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| Shrimp farming facility on sand of Mr. Nguyen Tien Cuong in hamlet 2, Dien Trung (Dien Chau). Photo: Viet Phuong |
Regarding technical requirements, you need to preparepondand the reservoir is carried out in 3 steps.
Step 2:For soil ponds, apply agricultural lime powder and dry the pond bottom for 20 - 30 days. The amount of lime is 3 - 3.5 tons/ha.
Step 3:For earthen ponds: Harrow thoroughly to let the lime soak into the bottom to kill all remaining shrimp, crabs, clams, snails, insects, and miscellaneous fish, kill bacteria in the mud, detoxify (heavy metals, H2S) and neutralize pH. For ponds lined with tarpaulin, it is necessary to clean and disinfect, wash the pond and sprinkle CaO lime mixed with thick water and water into the gaps between the tarpaulin.
Note:It is best to apply 50% lime powder CaCO3 and 50% dolomite CaMg(CO3). For lined ponds, mainly apply dolomite [CaMg(CO3)] until the alkalinity measurement meets the stocking standards.
Water collection and treatment is carried out in 4 steps:
Step 1:Take water into the pond through a thick cloth filter bag to remove trash, larvae, shrimp, crabs, clams, snails, insects, and miscellaneous fish, and let it stabilize for 3-7 days.
Step 2:Run the water fan continuously for 2-3 days to stimulate shrimp eggs, snails, insects, and miscellaneous fish to hatch into larvae.
Step 3:After running the water fan continuously for 2 - 3 days (to let the fish and shrimp eggs hatch), start killing the weeds with Saponin 15 - 16g/m3(If the pond water salinity is low < 20‰, soak it overnight and add salt to reach a salinity of 30‰ to increase the effectiveness of weed control); use Iodine, Over dine treatment at 5 - 6am to increase the effectiveness of Iodine because at that time oxygen and pH are lowest. The next day, check the alkalinity to reach 100 -120mg/l, if low, add Dolomite (black lime) until it reaches the standard.
Step 4:Supply water from the reservoir to the rearing pond through a filter bag, water depth from 1.3 - 1.4m.
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| People in Quynh Ngoc commune (Quynh Luu) prepare for the 2021 shrimp farming season. Photo: Trung Thanh |
To color the water, it depends on the conditions of each pond and the farmers' farming experience. However, you can refer to the following methods:
Method 2:Follow the formula 3:1:3 (ingredients include 3 kg of molasses + 1 kg of rice bran (or corn bran) + 3 kg of soybean powder). This formula does not need to be cooked, mix well then cover tightly for 12 hours. Use composted bran to fertilize to create color, dosage 2 - 3 kg/1,000 m3Water, fertilize continuously for 3 days, until reaching the required transparency (30 - 40 cm), 7 days later, add more fertilizer, reduce dosage by half compared to the original (based on water color to supplement).
Method 3:Use 5 - 6 liters of honey + 15g of bread yeast + 1 kg of food number 0 + 2 liters of clean fresh water, incubate for 24 hours, use for 1,000 m3, continuously color the water for the first 7 - 10 days, the best time to color is from 7 - 8 am.
Method 4:Use some quality microbial products on the market to create color. For example: Use 250g EZ Pon (Fementech) + 20 liters of clean water + 2 kg of soybean powder, anaerobically fermented for 24 hours, sprinkle evenly over 2,000 m3water, every 2 days/1 time, do it 3 times, after 6 days check water quality, pH, alkalinity, clarity... to ensure standards then proceed to release the seeds.
Selecting shrimp seeds, it is necessary to choose seeds that meet the Post 15 standards for black tiger shrimp and Post 12 standards for white-leg shrimp. At the same time, test the quality of shrimp seeds by sensory with criteria such as uniform size, large intestine, intestine-muscle ratio reaching the standard of 1/4, flexible swimming. Next, proceed to shock by suddenly reducing the salinity to only 50% (for example from 20‰ to 10‰), or shock with Formalin at a dose of 2 liters/10 liters of water for 1 hour, if the shrimp survival rate is above 90%, it is satisfactory. Then proceed to quarantine shrimp seeds.
Regarding seed release, farmers should ask hatcheries to acclimatize the salinity between the nursery and the pond. When releasing shrimp seeds, choose a cool time (morning, evening) and soak the shrimp bags in water for about 30 minutes to balance the temperature between the shrimp water in the bag and the pond before releasing./.
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