The following information is intended to describe the key environmental factors involved in the movement of a herbicide, such as acetochlor, through soil. In most soil environments, acetochlor is rapidly degraded and therefore poses no threat to ground or surface water quality. However, the ARP has determined that certain soils are particularly vulnerable based on soil texture, organic matter content, and depth to ground water, and have restricted the use of acetochlor on such soils. The following information is meant to help identify where such conditions may exist. Through Soil Several factors can affect the movement of a herbicide through the soil profile.
Soil texture is the percentage of sand, silt and clay.
Soil texture directly influences soil's ability to hold herbicides and fertilizer. As silt and clay content increase, adsorption increases because clay and silt bind more than sand. The following diagram, called the texture triangle, shows the relationship between different kinds of soil textures and their makeup. The sum of the percentage of sand, silt and clay at any point in the triangle is 100. Organic matter content also influences the amount of herbicide and fertilizer adsorption.