Take sulfur coated controlled release fertilizer as an example: there are micropores on the surface of the coated film, and the micropores are affected by thermal expansion and contraction, becoming larger or smaller.
In spring and summer, the temperature rises, rainfall is abundant, when the crop grows vigorously, the amount of fertilizer. The microporous membrane warming, soil moisture into the membrane, melting part of the fertilizer, liquid fertilizer nutrients from the membrane microporous outflow into the soil, for crop growth needs.
When a drought occurs, the soil is short of water, the fertilizer is difficult to release from the capsule in the form of liquid nutrients, avoiding the crop is burned due to excessive nutrients.
When the temperature drops, crops grow more slowly and need less fertilizer, at which time the micropores of the capsule become smaller and nutrient release is reduced accordingly, avoiding nutrient waste.
Compared with ordinary fertilizer, the utilization rate of fertilizer is improved. It can be said that the nutrient release law of controlled release fertilizer and crop fertilizer law is consistent, so it is also known as “intelligent controlled release fertilizer”.