Which method involves mixing herbicides with soil to enhance effectiveness?

Soil incorporation involves the method of mixing herbicides directly into the soil to improve their effectiveness in controlling unwanted vegetation. This technique allows the herbicide to be distributed more evenly throughout the soil profile, targeting the roots of the plants effectively. By being incorporated into the soil, the herbicide can also reduce the potential for volatilization or runoff that may occur with surface applications, ensuring that the chemical remains in contact with the target plants for a longer period.

The other methods listed do not focus on mixing herbicides with soil. Foliar application involves spraying the herbicide onto the leaves of the plants, while granular application typically refers to distributing solid herbicides on the surface or in the soil without necessarily mixing it in. Soil fumigation is a method that uses gaseous pesticides to treat the soil but does not involve mixing solid or liquid herbicides with soil in the same manner as soil incorporation. Each of these methods serves a distinct purpose, but soil incorporation is specifically designed to enhance the contact and effectiveness of the herbicide within the soil environment.