What must treated soil be covered with after application?

Treated soil must be covered with at least one-half inch of untreated soil after application to ensure effectiveness and safety. This layer of untreated soil helps to create a barrier that protects the treated area, while also preventing the application from being disturbed by environmental factors such as rain or erosion. The untreated soil acts as a protective layer, reducing the chances of the active ingredients leaching away and maintaining their effectiveness in controlling pests.

In contrast, covering treated soil with concrete, plastic, or only topsoil may not achieve the same protective benefits and could potentially interfere with the treatment's efficacy. Each of these alternatives could either trap moisture, impede proper application interaction with the surrounding soil, or fail to provide the necessary structure for ongoing pest management. Therefore, the requirement for a cover of at least one-half inch of untreated soil is designed to promote successful pest control while allowing for the natural ecosystem to continue functioning around it.