What exactly is Topsoil? Its the top most layer of the ground and if treated properly is home to thousands of organisms and composted nutrients. Typically, topsoil is made up of particles of Sand, Silt and Clay. Topsoil has no structural properties so its not a good material to build roads or foundations on, but topsoil contains the nutrients of life that are essential to successful plant growth. Most importantly, topsoil can hold water. If the ground you’re working on is too hard or too dry, its a good possibility that your soil needs to be amended. Without the proper nutrients in your soil the earthworms, spiders, fungi, and beetles have a hard time existing. These organisms are important for proper aeration of the soil, allowing for plant root development and to provide additional nutrition to developing root systems. The topsoil we sell at River Valley Soil has been screened to exclude rocks and debris, but also to improve the fluff of the soil for new lawn germination. Additionally, our premium topsoil includes composted leaf matter that immediately increases the amount of available nutrients (nitrogen) for optimal root development.