Which factors affect runoff when applying pesticides?

Runoff occurs when excess water flows over the soil surface, potentially carrying away pesticides and other chemicals. The correct answer highlights key factors like slope, vegetation, and soil characteristics, which significantly influence how much water can infiltrate the ground versus how much will flow off the surface.

The slope of the land is crucial because steeper slopes promote faster water movement, increasing the likelihood of runoff. Vegetation acts as a barrier that can slow down water flow and enhance infiltration, while soil characteristics—including texture, structure, and porosity—determine how well soil absorbs water. For instance, sandy soils may allow more rapid drainage and runoff compared to clay soils, which can retain water for longer periods.

Understanding these factors is essential for proper pesticide application because reducing runoff helps minimize environmental impact and ensures that the pesticides remain effective where they are intended to be used. The other options, while they may have relevance in other contexts, do not directly address the primary contributors to runoff in a way that impacts pesticide application as effectively as the factors in the correct choice.