Red Seal Agricultural Equipment Technician Practice Exam

How does soil compaction affect agricultural productivity?

1. Improves nutrient retention

2. Restricts root growth, reduces water infiltration, and decreases crop yields

3. Enhances soil aeration

4. Increases soil temperature

The correct answer is: Restricts root growth, reduces water infiltration, and decreases crop yields

Soil compaction has a significant impact on agricultural productivity primarily by restricting root growth, reducing water infiltration, and decreasing crop yields. When soil becomes compacted, the spaces between soil particles are compressed, which makes it difficult for roots to expand and access nutrients and water. This restriction not only limits the vegetative growth of plants but also impairs their overall health and productivity. Additionally, compacted soil has a poor structure, leading to reduced pore spaces that are crucial for water movement. When water cannot infiltrate effectively, it may result in surface runoff or pooling, thus reducing the water available for plant uptake. The combined effect of reduced root growth and inadequate water supply can lead to notably lower crop yields. Soil compaction does not improve nutrient retention—as nutrient availability can be affected negatively due to poor root penetration and water movement. It also does not enhance soil aeration; rather, compacted soil typically has lower aeration levels, which can further stress plant roots. Lastly, while soil temperature can be influenced by factors like moisture content and exposure, compaction itself does not inherently increase soil temperature in a way that is beneficial for agricultural productivity.