Fertilizer use methods and basic requirements
According to long-term tests and large-scale applications, the application of nitrogen containing 46% of urea 1 kg or nitrogen containing 17% of ammonium bicarbonate 3 kg of fish, the effect is equivalent to 80 to 100 kg of cow dung or grass, on the other hand, Urea or ammonium bicarbonate will increase production by more than 50% than if it is not applied.
(I) How to use chemical fertilizers Fertilizers can be divided into basic and topdressing applications, with different amounts of water and a depth of 1 to 3 meters. 1. Base application urea 1.5 ~ 2 kg, superphosphate 3 ~ 4 kg, potassium chloride 0.25 ~ 0.5 kg; if mu with ammonium bicarbonate (or ammonium bisulfate) 5 ~ 6 kg, superphosphate and chlorine The amount of potassium is the same as before, and it is applied to the base fertilizer of the joint fish pond. 2. Topdressing acres of urea 0.5 ~ 1 kg, superphosphate 1 ~ 2 kg, potassium chloride 0.25 ~ 1 kg; if using ammonium bicarbonate (or ammonium sulfate), superphosphate, potassium chloride, respectively Mu 2 to 3 kg, 1 to 2 kg and 0.25 kg. After being dissolved in water, they are splashed into fish ponds and splashed once every 7 days during the peak season. Agricultural ammonia is used as a basal fertilizer. The water level per acre is 15 to 20 kg; for topdressing, the amount is halved or 1/3. When applied in combination with potassium chloride, the base or application rates are 3-4 kg per mu, 0.25 kg, 2 kg, and 0.25 kg, respectively, once every 10 days. Agricultural ammonia should not be mixed with superphosphate at the same time. If necessary, it must be separated by 3 to 4 days.
(B), the basic requirements of fish fertilizer 1. A reasonable mix of fertilizer fish, according to the above-mentioned types of nitrogen, phosphorus and potassium, the amount of not too much, the interval can not be too short. 2. Scientific application At the same time as chemical fertilizer application, organic fertilizers such as pigs, chickens and cow dung should be applied every half a month. 400 to 500 kg of water per mu should be applied to make up for the lack of trace elements and organic matter in chemical fertilizers, and they must be staggered with chemical fertilizers. 3. For fertilizing fish, maggots, and tilapia, only applying chemical fertilizer is enough, no organic fertilizer is required. Mixing of herring, clams, clams, and grass carp requires the supply of animal and plant foods and compound feeds. 4. According to climate, water fertilization sunny, water temperature 17 °C ~ 28 °C, can be used according to the above dosage; if the weather is not good, the temperature is high, the water temperature above 30 °C, can be less or not Shi. If the pond water is black, brown or green red, it should stop using chemical fertilizers and immediately improve the water quality. Poor fish, can be used according to the above dosage, if the body is strong, can be applied less. Spring and autumn can be applied according to the above dosage; in the summer, less or no application is possible.
Hunan Academy of Agricultural Sciences Tan Yinchu