Which of the following is a non-structural erosion control practice?

The practice of temporary and permanent seeding is recognized as a non-structural erosion control practice because it involves the use of vegetation to stabilize soil and reduce erosion. By establishing plant cover, seeding helps to protect the soil surface from the eroding effects of rainfall and surface runoff. Additionally, the roots of the plants contribute to soil stability, helping to bind the soil together and further reduce the risk of erosion. This method is considered non-structural because it does not rely on physical structures or engineered systems; instead, it leverages natural processes and biological growth.

In contrast, the other options involve physical structures or engineered systems designed to control erosion and manage sediment. Silt fences, drainage swales, and check dams are all examples of structural practices. They typically require installation and maintenance of physical barriers or features to direct water flow or catch sediment, rather than focusing on natural stabilization methods like seeding. Thus, while all these practices are useful in erosion control, the non-structural approach of seeding is particularly effective and sustainable for managing erosion over time.