Certified Crop Advisor Practice Exam

Which characteristic is associated with poorly drained soil?

1. Aerobic

2. Pore space

3. Anaerobic

4. Saline

The correct answer is: Anaerobic

Poorly drained soil is characterized by anaerobic conditions, which occur when the soil retains excess water and limits the presence of oxygen. In poorly drained soils, saturation can lead to waterlogged conditions, where the air spaces in the soil become filled with water. This lack of oxygen impedes the ability of plants to take up nutrients and can result in the proliferation of anaerobic bacteria, which can affect nutrient cycling and root health. In contrast, aerobic conditions are linked to well-drained soils where oxygen is readily available for both plant roots and soil microorganisms. The concept of pore space is relevant, as well, since well-aerated soils typically have sufficient pore space to allow for both air and water movement. Saline soils, while they can sometimes be poorly drained, are defined more by their high salt content than their drainage characteristics. Thus, associating poorly drained soil with anaerobic conditions accurately reflects the challenges faced in managing such soils and highlights the critical influence of drainage on plant health and soil biology.