What Is Topsoil or Cow Manure Used For?

Topsoils

• Americans often equate a dark soil with the best topsoil. This stereotype is misleading and unwarranted. Topsoil types--sand, clay loam--vary from region to region. All three are productive in gardens as long as they naturally contain no more than 10 percent organic matter, have a variety of soil particles--to provide good aeration and water drainage--and contain a wide profile of nutrients. Not all topsoils are created equal, however. The best topsoils are free of debris, rocks and weed seeds. Topsoil should not be compacted or smell of rotting organic matter.

Cow Manure

• Cows, including both dairy and cattle types, produce manure comprising large amounts of digested plant materials. It's rich in organic matter and nutrients that further decompose when incorporated into topsoil, thereby creating a humus-type profile. Manure improves the aeration--both water retention and drainage--and increases fertility in soil with low amounts of nutrients. Topsoil with manure has a better tilth--or crumbly texture--and contains more beneficial soil microorganisms.

Topsoil Uses

• Topsoil provides the best environment for plant growth, especially for healthy root systems. With good planning, large earth-moving projects involving roads, parking lots or building construction can conserve the thin topsoil layer while less fertile soils are used to construct mounds, hills or create concrete form bases. When projects are complete, the fertile topsoil is placed atop the lower-quality fill soils. Topsoil is laid to support a wide array of plants to complete the projects. Lawns can grow on thin topsoil layers while trees need topsoil that's at least 18 inches deep.

Using Cow Manure

• Cow manure is added to topsoil to supply organic matter and nutrients. It's practical to add manure to topsoil that's frequently tilled and managed, such as in agricultural crop fields and vegetable gardens. Manure isn't as practical to add to lawns and orchards that aren't tilled every year; synthetic fertilizers are often better. Cow manure is dried and loses any offensive odor before being incorporated into topsoil. Wet cow manure is not only messy to spread, but it can physically burn plant tissues due to the concentrated solution of salts.