Fish seedlings hanging bag fertilization method

In the cultivation of fish fry fertilizer with inorganic fertilizer, if the whole pool sprinkled, fertilizer effect is fast, but the role of time is short. Many tiny particles of chemical fertilizers that are not yet completely dissolved are easily eaten by the fish and affect the survival rate of the fry. If fertilizers are put into plastic woven bags and allowed to dissolve and diffuse, they will not only have a stable fertilizer effect, low cost, and low labor intensity, but they will continue to provide phytoplankton with elements such as nitrogen and phosphorus to provide a large number of natural foods for fish fry and improve fry. The survival rate. The method is described below.
Hanging bag time: choose sunny bagging fertilization, from 9 am to 4 pm, strong light, phytoplankton photosynthesis is strong, the effect is good.
Bagging Fertilization Technology and Chemical Fertilizer Dosage: Nitrogen and phosphorus are indispensable nutrients for the growth and reproduction of phytoplankton. Commonly used nitrogen fertilizers are ammonium bicarbonate, urea, etc. Phosphate fertilizers include superphosphate, calcium magnesium phosphate fertilizer and so on. For example, if the depth of water is 1 meter, apply 4-5 kg ​​of ammonium bicarbonate per 667 square meters (1 mu) and 4 kg of superphosphate; or 2-3 grams of urea and 4 kg of superphosphate. Such as calcium magnesium phosphate fertilizer for 4-4-5 kg. Specific use depends on the weather, water temperature, and water quality, as appropriate.
How to use: Dissolve and spread the fertilizer into the bag. Each 667 square meters can be hung with 4-6 small plastic woven bags. The nitrogen and phosphorus fertilizers are respectively packed into the bags and hung into the fish seedling pool 20 cm underwater. The nitrogen and phosphorus fertilizers cannot be mixed in the same bag, because the nitrogen fertilizer absorbs heat and dissolves quickly, and it easily reacts with the phosphate fertilizer to reduce the fertilizer effect. Phosphate dissolves slowly and can hang 1- or 2-bags, but it can't be bagged with nitrogen fertilizer at the same time. It is better to add phosphate fertilizer in the morning and nitrogen fertilizer in the afternoon. Hang bags for 3 - 5 days once (depending on the fat and thin water). After injecting new water, it is necessary to hang bags in time and increase the number of hanging bags as appropriate.
Through a number of fish field trials in Anhui, in the past, the use of sprinkling method to top-dress fertilizers had a high cost, and the survival rate of fish fry was 30%. After top-dressing with bagging, the survival rate of fish fry was increased by more than 70%, and the fish fry were of neat specifications and robust in physique.

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