How to use water-soluble fertilizer? A full analysis of scientific application methods

Greenhouse soil is generally rich in phosphorus, so the technical requirements for water-soluble fertilizer are: 1. The fertilizer should be fully soluble and generally contain none or few secondary components that remain in the soil; 2. The phosphorus content in the fertilizer formula should preferably be low rather than high; 3. Sudden concentration damage is unlikely to occur; 4. Nitrogen has a sustained effect.

For the nutrient formula of water-soluble fertilizer for fruit vegetables, the total nutrient content of nitrogen, phosphorus and potassium is 45%, and the formula for the water-soluble fertilizer is determined as 18—6—21; the formula can also be adjusted appropriately according to specific conditions. To prevent concentration damage to vegetables, the potassium source in the water-soluble fertilizer should preferably be potassium sulfate or potassium nitrate, and potassium chloride should be avoided as much as possible. Among the nitrogen sources, ammonium chloride should also be used as little as possible, generally controlled within 20%, with nitrate nitrogen at 10% and the rest of the nitrogen as urea; the phosphorus in the water-soluble fertilizer is provided by monoammonium phosphate.

In the process of using water-soluble fertilizer, the following deviations should be prevented: 1. Using single-element urea, phosphate fertilizer and potassium fertilizer easily causes damage from excessively high salt concentration; 2. Because ordinary compound fertilizers are not fully soluble, they often produce too many insoluble substances; 3. The nutrient ratio selected for water-soluble fertilizer is not suitable for the requirement of water-soluble fertilizer with high nitrogen, low phosphorus and high potassium.