Slow-controlled fertilizers, as the name suggests, refer to fertilizers that release nutrients slowly or controllably. This fertilizer uses a special mechanism to allow nutrients to gradually decompose in the soil and be absorbed by plants, thus meeting the needs of crops for long-term growth. According to the principle of slow control, slow control fertilizers can be roughly divided into the following categories:
- Physical slow-control fertilizer: This type of fertilizer mainly realizes the slow release and controlled release of nutrients through physical means. Common methods include coating technology, in which fertilizer particles are encapsulated in one or more layers of membranes of different materials, such as polymers, waxes, etc., to regulate the rate of nutrient release. In addition, there are methods such as changing the physical form of fertilizer particles.
- Chemical Slow Control Fertilizer: This type of fertilizer regulates the release of fertilizer efficiency through chemical reactions. It is usually through the addition of chemical inhibitors, such as urease inhibitors, nitrification inhibitors, etc., or through chemical reactions to produce poorly soluble compounds, which are gradually decomposed in the soil and release nutrients for plant absorption.
- Bio-based slow-control fertilizers: These fertilizers use the action of microorganisms to regulate the release of fertilizer efficiency. By adding specific microbial agents, such as nitrogen-fixing bacteria, phosphate-solubilizing bacteria, etc., the fixed and released effects of microorganisms on nutrients are used to achieve the slow release of fertilizer nutrients. These microorganisms are able to symbiosis with plant roots, promoting nutrient uptake and utilization by plants.
- Compound slow control fertilizer: This type of fertilizer is made by combining two or more of the above slow control principles. For example, fertilizers that use both coating technology and chemical inhibitors, or use both microbial and chemical reactions to regulate the release of fertilizer efficiency. Compound slow-control fertilizer can combine the advantages of various slow-control methods to better meet the nutrient needs of crops.
With the development of modern agriculture and the improvement of environmental protection requirements, the role of slow control fertilizer in agricultural production is becoming more and more important. They can improve the utilization rate of fertilizers, reduce the number of fertilizer applications, reduce environmental pollution, and meet the needs of crops at different growth stages. Therefore, it is of great significance to understand the different types of slow-control fertilizers and their principles for rational fertilization and improve the efficiency of agricultural production.