what is topsoil
Topsoil as well as farm fertilizers and other potential pollutants run off unprotected farm fields when heavy rains occur. Topsoil is the upper, outermost layer of soil, usually the top 2 inches (5.1 cm) to 8 inches (20 cm).It has the highest concentration of organic matter and microorganisms and is where most of the Earth 's biological soil activity occurs. variety of soil mixtures are sold commercially as topsoil, usually for use in improving gardens and lawns, e.g. container gardens, potting soil and peat.