How much do you know about the ten taboos of fertilization in aquaculture ponds?

It is no wonder that fertilization in aquaculture ponds is either rare or easy to cause pond overturning accidents. It turns out that these taboos have not been taken seriously, so let's have a look at them quickly.

1, avoid fertilization in rainy days.

Fertilization in rainy days: first, the photosynthesis of phytoplankton in water is not strong, and the absorption function of elements such as nitrogen and phosphorus is poor; Secondly, more organic matter flows into the pond with rainwater, and the volume of the pond increases, which leads to the decrease of effective concentration of fertilization and affects fertilizer efficiency.

2. Avoid fertilization in hot days.

When the weather is sultry, the air pressure is low, the dissolved oxygen in the water is low, and the oxygen content of organic matter in the water increases after fertilization, which is easy to cause the pond to float and capsize due to lack of oxygen.

3. Avoid muddy water fertilization.

When the water is too turbid, there are too many clay particles in the pond water, and ammonium ions in nitrogen fertilizer and some ions in phosphate fertilizer are easy to be fixed and precipitated, so the fertilizer efficiency cannot be released, resulting in the loss of fertilizer efficiency.

4. Avoid single application of chemical fertilizer.

If only one kind of chemical fertilizer is applied, the nutrient elements are relatively single, and other nutrient elements will become the limiting factors, which will restrict the full play of fertilizer efficiency.

5. Avoid blind mixing.

When some acid fertilizers are mixed with alkaline fertilizers, it is easy to produce gas to volatilize or precipitate in the sludge, and lose fertilizer efficiency. Some ions of some inorganic fertilizers react with some ions of other fertilizers and lose fertilizer efficiency; Some ions are adsorbed by soil colloidal particles, which will also lose fertilizer efficiency. Therefore, not every fertilizer can be mixed.

6. Avoid fertilization in hot season.

According to the growth law of plankton, the fertilization season in aquaculture ponds is from April to 10 every year, and the water temperature is between 25℃ and 30℃ at noon on sunny days, but the higher the temperature, the better, because fertilization exceeding 30℃ in July and August will reduce the dissolved oxygen in water. If we still apply fertilizer blindly, it will not only waste fertilizer, but also pollute the water quality and cause the pond to overflow.

7. Avoid dry application of solid fertilizer.

Generally, solid nitrogen, phosphorus and potassium fertilizers are used, preferably dissolved in water and spread all over the pool. Because of their own gravity, solid nitrogen, phosphorus and potassium stay on the water surface for a short time and easily sink to the bottom, which affects fertilizer efficiency.

8. Avoid fertilization when the aquaculture body eats badly or has explosive diseases.

Fertilize when the culture is not strong in food intake, and a large number of plankton cultivated by fertilization can not be used effectively in time, which is easy to form blue-green algae and pollute the water quality; However, when the disease breaks out, the resistance of the culture is weakened, and the use of irritating chemical fertilizers is easy to cause the culture to die of poisoning.

9. Avoid one-off excessive fertilization.

Generally, topdressing is required once every 5 ~ 7 days. If there is too much fertilization and nitrogen accumulation in the pond, the oxygen consumption of organic matter in the water body will increase, which will easily cause the pond to turn over due to lack of oxygen. Therefore, fertilization must not save trouble, apply enough fertilizer at one time, and follow the fertilization policy of "a small amount and many times, less diligent hours".

10, avoid releasing surface water after fertilization.

After the fertilizer is applied to the water body, it is transformed into plankton population after a series of physical and chemical reactions for 3-5 days. Generally, it is evenly distributed at the water surface 1 ~ 1.5 meters. If surface water is released after fertilization, the number of cultured plankton will be significantly reduced, resulting in a decline in fertilizer efficiency. If agricultural water is really needed, it is best to drain it from the bottom.