Application Techniques Transport of pesticides to water may occur as a result of inaccurate application rates. Reasons most often identified were mistakes in calibration calculations, unknown or inaccurately marked tank volumes, worn nozzles, or inaccurate pressure gauges. In other cases, errors resulted from poorly maintained or outdated equipment, especially pumps and sprayer nozzles. Depending on the properties of the pesticide and soil conditions, over application of pesticides may result in leaching to ground water or runoff to surface water. Leaching Leaching is the movement of pesticides through the soil.
Pesticide leaching partially depends on the chemical and physical properties of the pesticide.
For example, adsorptivity which is the ability of a pesticide to bind with soil particles, influences the leaching potential of pesticides. A pesticide that binds tightly to soil particles is less likely to leach than one that does not. Another property of pesticides that influences leaching is the solubility of the pesticide. A pesticide that dissolves in water can move with water through the soil. Soil properties are an equally important consideration when looking at the leaching potential of pesticides to ground water.