Soil and Water Testing – Helpful Indicators for Selecting Turfgrass Varieties

Selecting the best turfgrass for a specific site involves a complete assessment of the unique conditions of each project. Soil and water testing play an integral role. Atlas Turf International regularly collaborates with clients from the beginning of the process to ensure the acquisition of the correct tests to acquire the most meaningful analysis.

The four main components for soil and water testing are:

  1. sampling
  2. laboratory analysis 
  3. interpretation 
  4. recommendations

Sampling is often the most erroneous part of soil and water testing.
Taking a representative sample is vital for obtaining meaningful data, resulting in more accurate interpretations and recommendations. Water samples should be taken from the actual irrigation sprinkler head as well as the irrigation holding area from which the irrigation water is being pumped. Soil samples need to be taken from the actual growing media that is going to be used including any amendments at the correct mixing ratio/percentage. In addition, some samples need to be taken from the existing profile in case migration issues occur. An important note here is to ensure that the nursery site growing media is exactly the same growing media as the designated site for play, be it a golf course or a sports field.

Laboratory Analysis. Soil tests reveal the amount of nutrients present in the samples and correlate with growth response, e.g., low levels will correlate with minimal growth. Soluble salts, pH levels, humus/organic matter, CEC, soil chloride, and electrical conductivity test results are also important to consider.

Interpretation of the laboratory results should be founded upon two basic principles: correlation and calibration. Correlation of nutrient availability and calibration to determine the fusion between soil and plant. Interpretation can vary depending on the differing philosophies of the individual or laboratory used.

Recommendations.  With the laboratory analysis and interpretation serving as the primary data, the remaining factors of the equation leading to the turfgrass recommendation are:

  • turf quality expectations of the turf manager, membership and ownership
  • management practices to be used
  • maintenance budget available
  • expected amount of use the playing area will receive annually
  • climatic conditions and weather patterns
  • any other challenges unique to this site

After evaluating the primary data in the context of the particular project circumstances, selecting the variety of turfgrass for the specific site is, in most cases, a much easier decision to make. Water tests are vital to determine water quality, which can range from clean – the ideal situation – to effluent or waste. Generally speaking, the closer the water is to the effluent end of the spectrum, the more negative attributes it will possess, such as high salts, bicarbonates and high chlorine levels.

With soil tests, the amount of available nutrients factor highly in grass type selection. How sensitive a turfgrass plant is to deficiencies and toxicities will also play a role in the selection process. Plant relationships with the soil are extremely important, as some nutrients, such as chlorine, are more mobile in plants than others. Using this example, chlorine levels in both the water sample and soil sample would be important to interpret as a factor in tissue toxicity causing salinity stress and leaf chlorosis. Chlorine levels in more sensitive turfgrass species may exhibit toxicity at 0.03 to 0.05 % (by weight) while other more tolerant species may endure 2.0% (by weight) or more.

Simply put, water and soil tests provide the onsite team and Atlas Turf International with the necessary data to ascertain long-term growing conditions leading to the most appropriate turfgrass selection for a project’s specific needs. The ultimate end result of proper turfgrass selection is the best possible playing surface.

Atlas Turf International