The leading cause of soil salinization in U.S. agriculture is excessive irrigation in arid regions, which leaves salt residues in the soil.

Soil salinization happens when salts build up in the soil, which decreases its fertility and negatively affects crop growth. In the U.S., the main cause of this issue is over-irrigation in dry regions, including parts of California, the Southwest, and the Great Plains. When irrigation water evaporates in these areas, it leaves behind salt. Poor drainage systems make the situation worse because salts do not easily wash away. This problem is especially serious in places that depend on groundwater or surface water with high mineral content. To fight salinization, it's essential to implement better water management practices, such as using drip irrigation and enhancing drainage systems.