What does leaching refer to in the context of soil?

Leaching refers to the process by which water-soluble nutrients are removed from the soil as water percolates through it. When it rains or when irrigation occurs, water moves through the soil layers, dissolving nutrients such as nitrogen, potassium, and phosphorous. As this nutrient-rich water moves downward, it may reach deeper layers or the groundwater, essentially depleting the upper layers of soil of vital nutrients necessary for plant growth. This process is particularly significant in agricultural contexts, where it can lead to reduced soil fertility if not managed properly. Understanding leaching is crucial for developing sustainable agricultural practices and maintaining soil health.

The other options relate to different soil processes, such as erosion or compaction, which do not specifically address the loss of water-soluble nutrients.