Leaching

to dissolve out by the action of a percolating liquid, taking away

"If you know your soil's potential for leaching and your pesticide's potential leaching, you are ready to determine the soil-pesticide interaction rating. You should know whether your soil has a high, intermediate, or low potential for leaching. You should also know whether your pesticide has a large, medium, small, or extra small potential for leaching. To see how these factors interact, refer to this chart (1)."

1. University of Illinois: College of Agricultural,
Consumer and Environmental Sciences, "50 Ways Farmers can Protect Groundwater", #24