Soil degradation causes are described as which of the following?

• A. Increased rainfall washing away nutrients
• B. Rising human population -> higher food demand -> increased agricultural production
• C. Decreased soil depth due to plate tectonics
• D. Improved irrigation practices

Answer: (B)

Soil degradation is driven by human pressure on land, especially when population growth pushes more food production. As the number of people rises, the demand for food increases, and farming is intensified to meet that demand. This often means more frequent cropping, extraction of nutrients, loss of crop residues, tillage that disturbs soil structure, and greater water use. All of these practices wear down the soil, reduce organic matter, and make it more prone to erosion and nutrient loss, which is exactly what degradation describes.

Other scenarios don’t capture the main driver as effectively. Rainfall can contribute to nutrient loss through erosion or leaching, but it isn’t the driver described by the phrase linking population growth to increased production. Plate tectonics don’t explain a degradation process on agricultural timescales, and improved irrigation typically helps reduce degradation rather than cause it.