NPK. This is fertilizer terminology. “N” means Nitrogen, “P” means Phosphorus and “K” means Potassium. When fertilizers are listed on the label they are always in this order and the number means the % of each element. In other words a 10-15-10 fertilizer contains 10% Nitrogen, 15% Phosphorus and 10% Potassium.
Organic Fertilizer. This is easier to define than organic products, as noted above. Organic fertilizers are generally thought to come from natural sources such as blood meal, manure, fish emulsion, etc.
