Certified Crop Advisor Practice Exam

What favors soil microbial activity?

1. Low pH Levels

2. Increased Soil Nutrients

3. Increased Temperatures and Soil Water Content

4. Reduced Organic Matter

The correct answer is: Increased Temperatures and Soil Water Content

Increased temperatures and soil water content create an ideal environment for soil microbial activity. Microorganisms in the soil thrive within certain temperature ranges where enzymatic processes are optimal. Warm temperatures can enhance microbial metabolism and reproduction, leading to a more active soil ecosystem. Additionally, adequate soil moisture is crucial for microbial functions, as it facilitates the movement of nutrients and substrates needed by microbes. Water acts as a solvent, allowing organisms to access essential nutrients more readily. When soil is too dry, microbial activity can slow down or become dormant. Similarly, if soil is saturated, anaerobic conditions may limit the types of microorganisms that can thrive, but a balanced level of soil moisture supports a diverse and active microbial community. By promoting both the right temperature and moisture levels, the conditions favor beneficial microbial processes such as organic matter decomposition and nutrient cycling, which are vital for soil health and plant growth.