What is leaching in terms of soil health?

Leaching refers to the process in which nutrients in the soil are dissolved in water and then carried downward through the soil profile into groundwater or deeper soil layers. This movement is significant because it can lead to the loss of essential nutrients that plants rely on for growth, such as nitrogen and phosphorus. When leaching occurs, these nutrients may end up in bodies of water, potentially causing environmental issues like eutrophication.

In contrast, retention of nutrients in soil pertains to a healthy soil structure that can hold onto vital minerals and organic matter, supporting plant growth. Soil compaction involves the compression of soil particles, reducing pore space and negatively affecting water infiltration and root growth. The evaporation of water from soil is a physical process where moisture is lost from the land surface to the atmosphere, which also does not directly relate to the movement of nutrients into groundwater. All these processes are interconnected in the context of soil health, but leaching specifically focuses on the downward transport of nutrients away from the root zone.