ABSTRACT
As soon as a herbicide is applied to its target, a number of processes immediately begin to remove the compound from the original site of application. This is the process of environmental fate. For the herbicide which is intercepted by plants, the chemical may be taken up by the plant itself (a process not addressed in this review), may be washed off by precipitation onto the soil, may undergo photodegradation on plant surfaces, or may volatilize back into the air (Figure 1). The herbicide which falls directly upon the soil or is washed onto the soil can undergo myriad processes which may be broken down into two main groupings: degradation and transport processes. Degradation processes include biological degradation by soil organisms and abiotic chemical and photochemical transformations. Transport of herbicides within the soil compartment can occur downward into the soil profile (leaching), across the soil surface (runoff), or into the air (volatilization). Each can be a combination of more fundamental processes including adsorption, convection, and diffusion. Potential routes of dissipation and degradation for herbicides. Note that each route is not independent of the others but forms an integrated whole. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780203752470/a2d06c4e-767d-4f45-99f8-17d278064d50/content/fig8_1_OB.tif"/>
