Nitrous oxide, a product of fertilizer use, may harm some soil bacteria‎

Plant growth is supported by millions of tiny soil microbes competing and cooperating with each other as they perform important roles at the plant root, including improving access to nutrients and protecting against pathogens. As a byproduct of their metabolism, soil microbes can also produce nitrous oxide (N2O), a potent greenhouse gas that has mostly been studied for its impact on the climate. While some N2O occurs naturally, its production can spike due to fertilizer application and other factors.