What affects mineralization and immobilization?
Decaying plant material, humus and/or organic matter in the soil are important sources of nitrogen. How much plant residue or organic matter are in the soil, and the types present, can affect the types of nitrogen conversion processes that take place. For example, the presence of a high amount of wheat straw or corn stalks in the soil will result in immobilization processes taking place. Immobilization results in plant usable forms of nitrogen in the soil becoming unavailable for subsequent crop growth. This nitrogen is used by microorganisms in the decomposition process of wheat straw or corn stalks. Once the wheat straw or corn stalks have become highly decayed, immobilization stops and mineralization starts. That is, plant usable forms of nitrogen such as ammonium become available again. Immobilization processes generally do not take place when a legume crop, such as alfalfa or white clover, is plowed under. Mineralization will likely be the dominant process. Conversion processes of
