What major issue does soil erosion primarily lead to?

Soil erosion is a significant environmental concern that primarily leads to a reduction in soil fertility. When soil is eroded, it often takes away the top layer, which is the most nutrient-rich part of the soil profile. This topsoil is crucial for supporting plant growth because it contains essential nutrients, organic matter, and beneficial microorganisms. Without adequate topsoil, the ability of the land to produce healthy crops diminishes, resulting in lower agricultural productivity and diminished fertility over time.

Additionally, while soil erosion can contribute to other issues, such as food scarcity and increased water pollution, the direct and immediate effect is on soil fertility. Eroded soil can also introduce sediments into waterways, leading to pollution, but the primary concern is the long-term capacity of the soil to sustain plant life, which is fundamentally tied to its fertility levels.