Slow-release fertilizers (SRF) provide a steady supply of plant nutrients over an extended period of time. These fertilizers are available in natural and organic forms to add nutrients to the soil naturally. This particular fertilizer can be used for all types of plants and trees. The correct usage of slow-release fertilizers in plants starts showing results gradually. Similar to NPK fertilizer, slow-release fertilizers are also available in different variations. So, based on the type of crop plantation, slow-release fertilizers must be chosen and should be used in agriculture or gardening areas to attain plant health benefits. Phosphorous, calcium, magnesium, potassium, and more nutrient requirements can be provided through slow-release (SRF) fertilizers.

Slow- and controlled-release fertilizers may contain only N or K, NP or NK (with different forms of K), NPK or NPK, plus secondary nutrients and/or different micronutrients. These different forms are only intended to add nutrients for good plant life. Micronutrients for plants are the most essential substances for healthier plant lives. In other words, slow-release fertilizers, aka organic fertilizers, take 2–7 days to mix with present plant nutrients. SRFs are now available in granules and powder to meet agricultural practices followed in many areas.