Many homeowners regularly add commercial fertilizers to their lawns and gardens to maintain a healthy balance of nutrients in soil  The widely available commercial fertilizers contain only macronutrients -- namely, nitrogen, phosphorus, and potassium
To remain healthy in the long term, soil for lawns requires the presence of these macronutrients and also trace amounts of micronutrients such as zinc, iron, and copper, which are depleted when grass clippings are raked up rather than allowed to decay and return to the soil
For soil to remain healthy in the long term, it requires the regular addition of both commercial fertilizers and a source of micronutrients such as grass clippings that are allowed to decay and return to the soil.