Slow and Controlled Release Fertilizer缓控释肥料

A slow and controlled release fertilizer is one whose nutrient release rate is significantly lower than that of conventional quick-acting fertilizers, achieved through coating, chemical synthesis or similar means. Under GB/T 23348, a slow release fertilizer must not release more than 15% of its nutrients within 24 hours in still water at 25°C, and no more than 75% cumulatively over 28 days.