Dual Enrollment Environmental Science Practice Exam

Soil structure comes from aggregates held together by natural organic matter and the activity of soil organisms. Disturbing the soil, especially by turning it over, breaks apart those aggregates, collapses pore networks, and disrupts the habitat of worms and microbes. This leads to less water infiltration, more surface runoff and erosion, and faster loss of organic matter as it decomposes with less protection. Tilling or plowing physically disrupts these connections and exposes soil to air, accelerating decomposition and reducing the spaces through which air and water move.

Mulching helps protect the surface, adds organic matter, and supports soil life, which tends to improve or preserve structure rather than destroy it. Crop rotation promotes a healthier, more diverse soil biological community and steady organic inputs, supporting better structure over time. Terracing reduces erosion by altering the landscape to slow water flow; while it involves some soil movement, it’s primarily a soil-conserving practice rather than a disturbance that disrupts soil aggregates on a daily basis.

So the practice most widely cited as damaging soil structure by disturbing the soil is tiling (tilling/plowing).