The optimal fertilization requirement for IHCAFE 90 depends on its high-yielding nature and nutrient requirements. As an experienced coffee grower, I have found that IHCAFE 90 benefits from a high level of fertilization to support its growth and maximize its yield potential. By providing the necessary nutrients in the right amounts, such as nitrogen, phosphorus, and potassium, IHCAFE 90 can thrive and produce excellent quality coffee beans. It is essential to regularly monitor and adjust the fertilization program to ensure optimal growth and productivity.