Which of the following methods of application mixes the pesticide into the soil?

The method that effectively mixes the pesticide into the soil is soil incorporation. This technique involves physically mixing the pesticide with the soil to ensure that it is evenly distributed and can effectively reach the targeted pests within the soil environment. By incorporating the pesticide, it becomes more accessible to pest organisms that inhabit or feed within the soil, which enhances its efficacy.

In contrast, foliar application targets the leaves and stems of plants, while surface spraying disperses pesticides over the top layer of crops or soil without mixing them into the soil. Granular application does involve spreading pesticide granules on the soil surface, but it does not guarantee that the pesticide will be mixed into the soil to the extent achieved through soil incorporation. This distinction is important for understanding how different application methods influence pest management and overall pesticide effectiveness.