Certified Storm Water Operator Practice Exam

For legumes, the soil pH should not be lower than what value?

1. 5.0

2. 5.5

3. 6.0

4. 6.5

The correct answer is: 6.5

Legumes are a type of plant that play a crucial role in soil health due to their ability to fix nitrogen in association with certain bacteria. For optimal growth and nodulation, which is essential for their nitrogen-fixing capability, legumes thrive in slightly acidic to neutral pH levels. A soil pH below 6.5 can hinder their growth by affecting nutrient availability and microbial activity in the soil. Maintaining a pH of at least 6.5 ensures that the essential nutrients, such as phosphorus and calcium, are adequately available to the plants. Additionally, a higher pH level can promote a favorable environment for the beneficial bacteria that form nodules on legume roots, enhancing their nitrogen-fixing ability. Therefore, ensuring that the soil pH is at least 6.5 is essential for achieving optimal growth and maximum benefits from legumes in agricultural and ecological systems.