1)Distinguish between fertilizer grade and fertilizer ratio
Fertilizer grade refers to the percentage by weight of the three primary nutrients in a fertilizer product - nitrogen (N), phosphorus (P), and potassium (K). For example, a fertilizer with a grade of 10-10-10 means it contains 10% nitrogen, 10% phosphorus, and 10% potassium.
On the other hand, fertilizer ratio refers to the relative proportions of the three primary nutrients in a fertilizer product. For example, a fertilizer with a ratio of 1-1-1 means it has equal parts of nitrogen, phosphorus, and potassium. The ratio helps determine how much of each nutrient is present in relation to the others in the fertilizer product.