Turf Tips >>>
How to Best Use
Diagnostic and Soil Lab Services By Dave Han, Ph.D. and Jim Jacobi, Ph.D.
Getting the most out of your soil testing Soil testing is vital to successfully growing any plant. Turfgrasses are no exceptions. But turfgrasses grow very differently to most other crops, so sampling and implementing recommendations are different in turfgrasses from most crops. Here is how to get the best information and benefit out of your soil testing for turfgrass.
How turfgrasses make soil testing a bit more complicated The main difference between turfgrass and row crops or vegetable gardens is that turf is perennial. Because it is not replanted every year, there is no time when lime or fertilizers can be incorporated into the soil throughout the entire rootzone. Turfgrass also covers the ground completely, ideally leaving no bare soil showing, so any lime applied to the top
of the turf must work its way through the thatch to even reach soil, then move down through the soil profile. This means that changes in soil pH due to lime applications, for example, happen very slowly in soils growing continuous turfgrass. A good rule of thumb is that most turfgrass roots are in the top three inches or so of the soil, though of course there are exceptions both ways. It can take months or even years for lime to work its way down that far into the soil profile. If lime is applied to soil under turfgrass on a regular basis, a large difference in pH over very small changes in depth can build up over time. This can have a big influence on the way the grass grows. We will return to this issue later.
Collecting a good sample The whole point of soil testing is to give growers (in this case, turf managers) the information they need to make sure that the soil will support the healthiest plants possible. For
Al ab ama Tu rf Tim e s > >> Spr ing 2019
Continued on page 22
20
