There are many things that can be done to improve turfgrass health, quality, and performance but few offer as much return on investment as soil sampling. Often for as little as a few dollars, soil tests can provide a vast amount of information to help make important decisions on the application of fertilizers, lime, gypsum, irrigation, soil amendments, and more. This simple test is one of the most important tools in maintaining dense, healthy turfgrass and can even be helpful in reducing inputs and costs.
Soils are complex systems made up of a vast array of physical, chemical, and biological properties. In turfgrasses, it provides not only nutrients and water but also serves as the foundation for athletic fields and golf courses where traction, stability, and resiliency are important for events.
Many basic soil tests provide information on soil chemical properties including pH, plant nutrients, soluble salts, cation exchange capacity, base saturation, and more. Other, more detailed soil tests, can also provide information on soil physical properties such as soil textural analysis (% sand, silt, clay), hydraulic conductivity, bulk density, porosity, water retention, and so on. While these types of detailed tests are typically most utilized in the golf course and sports field industries, a basic soil test can be helpful to any site, especially home lawns. This is especially true in urban or suburban settings where soils have been disturbed, altered, or even removed during construction.
Information on soil pH and nutrients is often most commonly associated with soil testing. Soil pH is essentially a measure of the acidity (<7) or alkalinity (>7) of soil. This is important because it can impact nutrient availability, plant health, create imbalances or toxicities, and even the performance of herbicides or insecticides. Most turfgrasses perform best in a soil pH of 6.5 to 7, and soil tests are the best way to determine how to alter it if necessary. Soil tests also provide information on nutrient status, desired ranges, and the likelihood of response from fertilizer application. Savings from the reduction or elimination of even one unnecessary nutrient application will often far exceed the cost of the soil test itself.
In areas of the world where salts are prevalent in soils and aquifers, soil testing is a great way to monitor salt accumulation and develop a strategy for mitigation. As saline water is applied through irrigation, water is taken into turfgrass roots and transpired through leaves, while leaving damaging salts behind. Salt accumulation can lead to a number of issues in plant health including water deficits, ion imbalances or toxicities, and decreases in soil permeability.
The vast diversity that exists worldwide in soils, groundwater, rainfall amounts, etc. make it impossible to predict the chemical, physical, and biological properties of soils. It’s hard to imagine maximizing plant health and performance without knowing the basic information provided by soil tests, and often for a few dollars, euros, pounds, or rubles the vast complexities that exist just below our turfgrasses can be brought to life. Various types of soil tests from university, governmental, or private labs can provide information on each of these factors with little difficulty or cost, so check with one in your area to get started.