Topsoil as an InvestmentWhile there are ways of adjusting and improving the existing soil conditions of your yard, these methods take time and may not be dramatic enough, especially in areas where little or no soil exists to begin with. After all, it can take hundreds, if not thousands of years to make a few inches of quality topsoil. For many homeowners, purchasing topsoil is one of the best investments they can make for their landscape. The topsoil business is now a multimillion dollar industry in the United States. It’s purchased by the bag and by the dump truck load. But what exactly is topsoil, and what should you look for when purchasing this “black gold?”
Topsoil vs. SubsoilAlthough there’s no legal definition of topsoil, scientifically speaking topsoil is defined as the A horizon, or the surface layer of a soil. It’s the area where organic matter can be found and contains the most nutrients needed for plant growth. Depending on where you live in the country, the topsoil layer can be anywhere from nonexistent to several inches deep. Under the topsoil, another layer known as the “subsoil” layer can be found. These subsoil layers are usually low in organic matter, nutrients and other beneficial material. Subsoils can also contain high levels of clay and salts. Unfortunately, many soils sold as topsoil are nothing more than subsoils that were removed during construction projects.
Soil TestingTo avoid paying high prices for poor soil, there are a few things to look for. First, ask the vendor for the soil’s test data. This data should include the soil pH level, soluble salt content, texture, organic matter content and nutrient concentrations. If the vendor does not have the data available, obtain a small sample and have the soil tested yourself. Soil tests are available with help from your local Cooperative Extension service. Once you receive the report, your Cooperative Extension service can help you analyze it. You can also learn how to read a soil report here.
Ask QuestionsYou should also ask plenty of questions about any topsoil you’ll be purchasing. Be sure to ask whether the topsoil was treated with herbicides of any kind. If it was treated, find out how long the chemical remains active in the soil. This could have big impacts as you begin to sow seed into it. You should also try to find out the source of the topsoil and if it’s been screened to remove roots, rocks and other large debris.