Chemical fertilizers are synthetic substances that provide the necessary nutrients for healthy plant growth and development. Chemical fertilizers combine synthetic forms of the primary macronutrients for plants such as nitrogen, phosphorus and potassium, as well as a variety of micronutrients and additives. Synthetically developed fertilizers provide the benefit of having more nutrients per pound than organic fertilizers, thus reducing costs. Chemical fertilizers have many uses for the average gardener and homeowner, as well as for commercial use.