What are absorbent materials primarily used for in the context of fertilizer application?

Absorbent materials are primarily utilized for the immediate cleanup of liquid spills, particularly in scenarios involving fertilizers. When a spill occurs, these materials help contain and soak up the liquid, preventing environmental contamination and minimizing hazards associated with spills. This rapid response is crucial for maintaining safety and managing the potential risks of fertilizer runoff or leakage.

The other options pertain to different concepts. For example, measuring fertilizer effectiveness involves assessing how well the fertilizer promotes plant growth, while enhancing soil aeration and improving nutrient absorption relate to the physical and biological properties of soil rather than spill management. Thus, the use of absorbent materials is specifically tied to spill response, making it the correct context within fertilizer application practices.