Which application method involves minimum mixing of soil when injecting herbicides?

The application method that involves minimum mixing of soil when injecting herbicides is soil injection. This technique is specifically designed to deliver herbicides directly into the root zone of the target plants or into the soil without significantly disturbing the surrounding area.

Soil injection methods utilize specialized equipment that creates holes or channels in the soil, where the herbicides are precisely delivered. This method ensures that the active ingredients are placed in close proximity to the roots of the target weeds or plants, allowing for effective uptake while minimizing disruption to the soil structure and surrounding vegetation.

In contrast, surface application, soil mixing, and granular application involve more interaction with the soil. Surface applications broadcast herbicides over the soil surface and usually require some form of incorporation through rainfall or irrigation, leading to more soil disturbance. Soil mixing involves physically turning over and mixing the herbicides into the soil, which also results in significant soil disturbance. Granular application may require watering-in for activation, further affecting the surrounding soil compared to the targeted approach of soil injection.

Thus, soil injection stands out as the method that minimizes soil mixing while ensuring effective herbicide placement.