denitrification 1. The loss of nitrogen from soil by biological or chemical means. It is a gaseous loss, unrelated to loss by physical processes such as through leachates. 2. The breakdown of nitrates by soil bacteria, resulting in the release of free nitrogen. This process takes place under anaerobic conditions, such as are found in water-logged soil, and it reduces soil fertility[di:ˌnaitrifi'keiʃən]Sub.
