Texas FFA Nursery Landscape Practice Exam

What factor can negatively impact soil drainage?

1. High organic matter content

2. Flat terrain

3. Poor soil structure

4. Sand soil

The correct answer is: Poor soil structure

Soil drainage is crucial for ensuring that plants receive the right amount of water while preventing issues such as root rot and nutrient leaching. The correct choice pertains to poor soil structure, which can significantly impede drainage. When soil structure is poor, it means that the soil particles are not well arranged, leading to compacted layers or clods that restrict the movement of water. In soils with poor structure, the pore spaces are often smaller or irregular, making it difficult for water to percolate through. This poor arrangement can trap water, resulting in saturated conditions that are detrimental to plant health. Improving soil structure often involves incorporating organic matter, aeration, or other amendments to create a looser, more aggregated soil that enhances drainage. Other factors like high organic matter content and sandy soils tend to improve drainage. While flat terrain might slow down surface water runoff, it does not inherently cause poor drainage; drainage issues are more directly linked to soil structure and composition. Therefore, understanding the relationship between soil structure and drainage is crucial for effective land management and plant health.