For most homebuyers, soil quality is probably not very high on the wish list when it comes to selecting a house. You’ll probably never have a realtor use a soil probe during a home showing, or exclaim how the backyard features a swimming pool, deck and beautiful sandy loam with a pH of 7.2. It’s not until you realize your landscape is perpetually wimpy that maybe there’s something wrong with the soil. This problem is all too common, especially nowadays as more and more homes are being built on steep, rocky hillsides devoid of a decent soil layer.
Topsoil as an Investment
While 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. Subsoil
Although 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 Testing
To 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 Questions
You 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.
Get Your Hands Dirty
There are also some visual and hands-on examinations you can do while inspecting a load of topsoil. Grab a handful of soil and give it a good smell. Any soils that smell heavily of chemicals or any other unnatural odor should be rejected. Be sure to inspect the color of the soil. As a general rule, the darker the soil the higher the organic matter content. Also be sure to check the soil surface for salt crust. Saline soils will develop a light colored salt layer on their surfaces, and these soils should be rejected. Finally, look for any aggregates (dirt clods) and break them apart in your hand. They should crumble easily. If the clods are very hard and difficult to break apart with your hand, re-think purchasing the soil.