Texas FFA Nursery Landscape Practice Exam

What is the ideal composition of soil?

1. 25% solid material, 25% air, 50% water

2. 25% air, 25% nutrients, 50% water

3. 25% solid material, 25% water, 50% air

4. 25% water, 25% air, 50% solid material

The correct answer is: 25% water, 25% air, 50% solid material

The ideal composition of soil is generally recognized to be approximately 25% water, 25% air, and 50% solid material, including minerals and organic matter. This balance is crucial for creating an optimal environment for plant roots, allowing for proper drainage, aeration, and nutrient availability. Having 50% solid material ensures that there are enough nutrients and minerals present for plant growth, as plants rely on these components for essential sustenance. The 25% water component is vital for hydration, providing moisture that facilitates nutrient absorption and biological processes in the soil. Lastly, the 25% air is important for root respiration and maintains a balance in soil structure, preventing compaction and allowing for adequate oxygen levels in the root zone. This composition supports not only plant health but also soil microbial activity, which is essential for nutrient cycling and overall soil health. Each element plays a critical role in forming a well-functioning soil ecosystem.