Texas FFA Nursery Landscape Practice Exam

Which of the following is a key benefit of organic matter in soil?

1. It compacts the soil

2. It decreases soil aeration

3. It enhances plant growth by improving nutrient availability

4. It prevents water retention

The correct answer is: It enhances plant growth by improving nutrient availability

Organic matter in soil is crucial for multiple reasons, but one of its most significant benefits is that it enhances plant growth by improving nutrient availability. When organic matter decomposes, it releases essential nutrients such as nitrogen, phosphorus, and potassium in a form that plants can readily absorb. This nutrient release is vital for healthy plant growth and increases the overall fertility of the soil. Additionally, organic matter improves soil structure, which in turn helps with the retention and movement of air and water within the soil. This benefits root development and overall plant health. The presence of organic matter also promotes microbial activity, which supports the nutrient cycling process essential to plant growth. In contrast, options that state organic matter compacts the soil or decreases soil aeration are not correct because organic matter actually helps to create a loose, well-structured soil that allows for better aeration and drainage. Likewise, organic matter does not prevent water retention; rather, it improves soil’s ability to hold moisture, thereby benefiting plant growth.