What is the effect of immobilization on soil nitrogen availability?

Immobilization refers to the process by which soil microorganisms take up inorganic nitrogen forms, such as ammonium and nitrate, and convert it into organic forms within their biomass. During this process, nitrogen becomes temporarily unavailable to plants because it is being sequestered by the microorganisms rather than remaining in a form that plants can use.

When immobilization occurs, the nitrogen that is taken up by microbial populations essentially "locks away" this nutrient. As a result, the immediate availability of nitrogen for plant uptake decreases. Eventually, when these microorganisms die or when organic matter is decomposed, there is a potential for this nitrogen to be released back into the soil as inorganic nitrogen through mineralization. However, during the period of active immobilization, the overall effect is a decrease in nitrogen availability for plants.

This understanding of immobilization is crucial for nutrient management, as it highlights the dynamic nature of nitrogen cycling in soil and the importance of considering microbial activity when assessing nutrient availability for crops.