Topsoil is geology modified by biological, physical and chemical processes. Without topsoil, our planet would be just rocks and dust with no meaningful life. We all should know where our food comes from. The thin layer of topsoil covering our planet gives and sustains most all of the life we know. It is basic knowledge that a handful of soil contains billions of bacteria, protozoa, fungi, nematodes and earthworms to name a few.
Question: Why do we treat our topsoil like dirt?
Everyone has seen the dirt blowing because of all the wind we have experienced this spring (photo 1). Soil out of place is dirt! If it is so critical to our existence, why do we just accept it when we see wind or water erosion? It is not the wind or rain’s fault when erosion occurs. Soil erosion is a direct result of poor land management choices. Ground cover (armor) with plants (dead or alive) anchored into the soil are required to stop erosion. Topsoil armor reduction is a result of too much tillage or over-grazing. Fields managed with topsoil armor in mind have greatly reduced erosion.
Question: What is the value of topsoil?
It is common knowledge that it takes a considerable amount of nutrients to grow field crops and food. We measure the soil ability to provide plant essential nutrients through soil testing procedures.
Even though our plants get the carbon needed for building dry matter from the air, we know that soils higher in carbon are generally the most productive and fertile. All we have to do is measure the value of our topsoil. Recently, samples of the soil (dirt) blown into the road ditch were analyzed for nutrient concentrations similar to the situation in the photo.
Question: Is the dirt in the road ditch the best or worst topsoil from the adjacent field?
With absolute confidence, we know this is the best topsoil from the adjacent field. Table 1 shows the nutrient concentrations and monetary values for each measured parameter considering 1 inch of topsoil across 1 acre.
The test results come from a sample of soil blown into a road ditch somewhere in South Daktoa. However, it probably is a good representation for most areas.
