Loam is composed of a mix of sand, clay, silt and organic materials and it is the ideal type of soil when it comes to nutrient levels. Topsoil is the uppermost layer of soil ranging from 2-10” made up of decaying organisms, plant matter composed of the native soil in combinations with organic matter that has built up over time. It contains living organisms such as worms and insects. Screened loam is perfect for lawns and for starting a garden or raised bed.