Fertilizers and soil amendments are a wide array of materials added to soils to improve plant growth. They can be organic, such as bone meal, or inorganic, such as 10-10-10 fertilizers. They serve as both fertilizers and soil amendments.
Many farmers do not have a clear understanding of soil testing. Confusion revolves around the fact that the nutrient content of soil seldom is important in testing for fertilizer recommendations (Fertilizer Formula) because of the many chemical forms of nutrients in soil.
Nitrogen (N), phosphorus (P), and potassium (K). Fertilizers are labeled with a three number analysis corresponding to N, P, and K. It tells what percentage of the net weight is actually composed of these three nutrients. A fertilizer containing all three nutrients is a balanced fertilizer.