What is the first thing that happens to a herbicide after it is applied to water?

When a herbicide is applied to water, the initial process that occurs is dilution. After application, the herbicide disperses throughout the water body, mixing with the water and reducing its concentration. This is significant because the effectiveness of the herbicide can be influenced by the rate of dilution; greater dilution can reduce the herbicide's efficacy on target aquatic plants.

While absorption and adsorption also play roles after application, these processes occur later as the herbicide interacts with soil or plant surfaces. Degradation refers to the eventual breakdown of the herbicide over time but is not the immediate effect noticed right after application. The immediate and significant action that follows the application of a herbicide in an aquatic environment is hence dilution, making it a key concept in understanding herbicide behavior in water bodies.