Soil texture, organic matter content, and permeability are soil factors affecting pesticide movement. The physical and chemical properties that make pesticides effective for pest control also create a potential for groundwater contamination. Persistence is the lasting power of a pesticide. Most pesticides in the soil break down or degrade over time as a result of several chemical and microbiological reactions. Adsorption is the process that binds pesticides to soil particles, like iron filings or paper clips sticking to a magnet.
Adsorption occurs because of the attraction between chemicals and soil particles.
Factors controlling pesticide adsorption include pesticide charge, soil pH, temperature, water content, and the amount of organic matter present. The label is a legal document and its instructions should be carefully read. One section will inform you of environmental hazards associated with the pesticide's use. Several common warnings relate to groundwater protection. Other warnings refer to permeable soil types, depth of groundwater, distance to wells, runoff potential, and endangered species.