What does 'drift' refer to in pesticide application?

The term 'drift' in pesticide application specifically refers to the airborne movement of pesticide away from the target area where it is intended to be applied. This can occur due to various factors such as wind, temperature inversions, or other atmospheric conditions that allow the fine droplets of pesticide to become airborne and transport away from the site of application.

This phenomenon is particularly important to understand in the context of environmental impact and pesticide efficacy. When pesticides drift, they can inadvertently affect non-target organisms, such as beneficial insects or nearby crops, and may pose risks to human health and the environment. Thus, recognizing and mitigating drift is crucial for responsible pesticide application practices.

While the other options touch on related concepts, they describe different issues. The movement of pesticide from one field to another could encompass various types of transport, but does not specifically indicate airborne movement. The accumulation of pesticide residues in the soil relates to persistence and degradation over time, whereas runoff describes the transport of pesticides into water bodies due to water movement rather than air. Therefore, the definition that aligns most closely with the concept of drift is the airborne movement of pesticides away from the intended application site.