出典:Wikipedia
出典:『Wikipedia』 (2011/04/19 13:26 UTC 版)
A Controlled Release Fertilizer (CRF) is a solid form fertilizer, usually in powder or small granules that are either sprinkled on top of the soil (top dressed) or dug into the soil before planting. The outer layer is insoluble but permeable so nutrients are released slowly in a controlled way over a set period. Other names for controlled release fertilizers are "metered-release fertilizers" and "slow-acting fertilizers".