A Detailed Guide to the Characteristics and Correct Use of Flush Fertilizers

Flush fertilization is a common method of topdressing in agricultural production. It refers to dissolving fertilizer in water and flushing it into the field along with irrigation, so that nutrients seep into the soil near the crop roots with the water and are absorbed and used by the root system. By convention, people also directly call quick-dissolving fertilizers suitable for this method flush fertilizers.

In terms of types, flush fertilizers mostly use varieties that are easily soluble in water and have a fast fertilizer effect, such as water-soluble fertilizers and quick-dissolving compound fertilizers; fully decomposed manure can also be diluted and applied by flushing. This type of fertilizer releases nutrients quickly and can promptly supplement the nutrients crops need during their vigorous growth period, and it is relatively common in protected cultivation such as vegetable greenhouses.

When using flush fertilizers, the principle of small amounts applied many times should be followed, and the amount used each time should not be too large, so as to avoid burning the roots due to excessive concentration. The amount of water when irrigating should be moderate to prevent nutrients from leaching away with the water. Flush application should avoid the high-temperature period at noon, and it is more suitable to carry it out in the morning on a sunny day; at the same time, it should be used in combination with base fertilizer, so that base fertilizer and topdressing complement each other.

It should be noted that although flush fertilization saves labor and effort, its fertilizer effect lasts for a relatively short time, and flush application alone cannot meet the needs of crops throughout the entire growth period. Undecomposed manure must not be applied directly by flushing, otherwise it is likely to burn roots and introduce diseases and insect pests. Long-term excessive flush application may also cause soil compaction and salt accumulation, so the amount used should be reasonably controlled to maintain nutrient balance.