What makes organic fertilizers better than manufactured, chemical fertilizers? After all, nitrogen, phosphorus, and potassium, the nutrients that plants require most, ARE chemicals. So what's the difference? Natural and organic fertilizers feed your plants while building the soil. Repeated applications of inorganic fertilizers which usually provide only those three macro-nutrients -- N, P, and K -- can deplete soils while harming earthworms and micro-organisms that keep soil alive and make nutrients available to your plants.