Certified Storm Water Operator Practice Exam

What is a common characteristic of bonding that can impact soil stability?

1. Soil color

2. Moisture levels

3. Organic matter

4. Plant roots

The correct answer is: Organic matter

Organic matter plays a crucial role in bonding within soil, greatly influencing its stability. This component aids in the aggregation of soil particles, creating a more cohesive structure that improves the soil's ability to retain water and nutrients. High levels of organic matter enhance the soil's resilience against erosion and other forces that might destabilize the soil structure. In addition, organic matter contributes to the formation of soil aggregates, which are clusters of soil particles held together by organic materials. These aggregates improve the porosity and permeability of the soil, allowing for better drainage and air movement, which are essential for healthy plant growth and soil stability. While moisture levels do influence soil stability by affecting the weight and cohesion of soil particles, they do not inherently create the bonding that organic matter does. Likewise, while plant roots can help stabilize soil through physical anchoring, it is primarily the organic matter that enhances the chemical and physical bonding of soil particles. Soil color can provide information about the organic content or other properties but is not a direct characteristic of bonding impacting stability. Thus, organic matter is the most significant factor in this context regarding soil stability through bonding characteristics.