Understand your soil to level up your turf management

Lisa Beirn

In the simplest sense, you can define soil as the medium in which plants grow. The often-overlooked reality is that soil represents a diverse, complex ecosystem that is the foundation that allows plants, animals and humans to thrive. By understanding soil properties and how to manage them, turfgrass managers can encourage healthy plants and environments.

Minerals (clay, sand or silt), organic matter, living organisms, water and air make up soil. The amounts and proportions of each of these components drive the physical, chemical and biological properties of soil.

Physical properties represent attributes such as soil texture, color, consistency, density and porosity. Chemical properties include pH and nutrients. Biological properties include organic matter decomposition, pest suppression and nitrogen mineralization.

Know your soil

Knowing the properties of your soil is vital for proper management. For example, soils with a high sand content will have less ability to hold water and nutrients. They dry out faster and are usually well-drained, resulting in turf that may not have enough moisture or nutrients to thrive. Soils with more clay can hold more nutrients and water but tend to dry out more slowly. Clay-based soils are also more prone to compaction, resulting in thin turf that can be more susceptible to wear. Incorporating organic matter, such as compost, into the soil profile can help in both situations.

Turfgrass managers can work compost into the soil following aeration in the spring or fall. Apply compost in a thin layer evenly across the surface and then brush into aeration holes. It can take a few seasons to see results and the process likely needs to be repeated. If conducting a complete soil renovation, aim for loamy soil. Loam soil represents an equal mix of sand, silt and clay particles and is often considered ideal for turfgrass.

Soil pH also influences plant health by driving nutrient availability. In most cases, extremes in pH decrease the nutrients available to plants. It can also affect microbial processes. For turfgrass, an acceptable pH range is between 5.0 and 7.0, depending on the species grown.

Understanding the soil type will help you better manage the nutrient needs of your turf. (Photo: HappyNati/iStock / Getty Images Plus/Getty Images)

Take a sample

Portable pH meters are available, but it’s preferred to get a soil test because it also will provide valuable information on nutrient status and cation exchange, or the ability of the soil to supply nutrients to plants. When collecting samples for soil testing, always sample to rooting depth. This tends to be in the 3- to 4-inch range for turfgrass. Remove any thatch or mulch from the sample, as this can bias results.

Take multiple samples from the lawn in a random pattern and be careful to sample at the same depth each time. These subsamples can be combined into a composite and analyzed. If one area has different soil types, drainage or other physical properties, test it separately. Soil tests will generally include recommendations along with fertility and pH results.

Maintaining healthy soils is the first step toward a healthy lawn for your clients. Combining soil management techniques with a sound agronomic program is the best approach for long-term success in turfgrass management. To learn more about newly developed agronomic programs for lawns tailored for your area, visit GreenCastOnline.com/lawn-programs.