Slow-release fertilizers are designed to release at a rate more consistent with plant needs. Slow-release fertilizers are usually more expensive than soluble fertilizers. The choice of soluble or slow-release nitrogen depends on the reason for fertilization. Soluble fertilizers may be required when a quick response is desired, and slow-release fertilizers are excellent for regular maintenance. Fertilizers are also formulated with a combination of soluble and slow-release nitrogen.
Fertilizer is available in dry and liquid forms.
There is no difference in uptake from these forms. Both require irrigation or rainfall to distribute nutrients in the soil water solution so they are available for uptake. Learn to read the fertilizer analysis. Use soluble fertilizers for a quick response. Use slow-release fertilizers for regular maintenance.