Q: What is the difference between a synthetic and a natural fertilizer?
A. Natural fertilizers are organic products that have been extracted from living things or from the earth. They can be either plant-derived or animal-derived. Some examples would be mushroom manure, blood meal, bone meal, cottonseed meal, kelp meal, poultry or horse manure (aged) and compost. Synthetic fertilizers are those composed of the synthesized chemicals of nitrogen, phosphorus and potassium. In general, natural fertilizers contain lesser amounts of N-P-K than their synthesized counterparts, so you need to use more of them to supply the plant with the required amount of nitrogen, phosphorus or potassium. However, because natural fertilizers add vital organic matter, they also improve soil texture — an important advantage.