Certified Crop Advisor Practice Exam

If a nutrient is released into the soil during decomposition of an organic material, what has occurred?

1. Leaching

2. Mineralization

3. Nutrient fixation

4. Carbon sequestration

The correct answer is: Mineralization

When a nutrient is released into the soil during the decomposition of organic material, this process is referred to as mineralization. During mineralization, microorganisms break down organic matter, such as plant and animal residues, converting complex organic compounds into simpler inorganic nutrients. This crucial process not only makes nutrients more available to plants but also plays an essential role in soil health and fertility. In the context of nutrient cycling, mineralization contrasts with processes like leaching, where nutrients are washed away from the soil by water, potentially leading to nutrient loss. Nutrient fixation refers to the conversion of inert forms of nutrients, mainly nitrogen, into forms that plants can use, typically associated with certain soil bacteria. Carbon sequestration involves capturing and storing atmospheric carbon dioxide, primarily focusing on its role in climate change mitigation rather than directly relating to nutrient availability in the soil. Thus, mineralization accurately describes the process of releasing nutrients into the soil during decomposition.