The process by which ammonia compounds, including man-made fertilizer and the humus provided by organic matter or plant and animal origin, are converted into nitrites and then nitrates, which are then absorbed as a nutrient by crops.
the oxidation of ammonium compounds into nitrates by soil bacteria
the oxidation of ammonium compounds in dead organic material into nitrates and nitrites by soil bacteria (making nitrogen available to plants)
the chemical process in which a nitro group is added to an organic compound (or substituted for another group in an organic compound)
