Soil pH In Simple Terms
By Jon Cooner, Institute Product Consultant
“What exactly is soil pH, and why is it such a big deal?” That’s one of the most common questions our customers
ask the Whitetail Institute. It’s also one of the most important. Thankfully, the answer is relatively simple if the
person giving the explanation does not unnecessarily overcomplicate it. I have seen other experts asked the
same question at outdoor shows we attend, and while some field it well, others seem more concerned with their
egos than with educating others. The latter reveal themselves rather quickly with scenarios like the following:
A group of hunting buddies approaches a booth at an outdoor show, and one in the group asks the resident
“expert,” “By the way, everyone keeps saying that soil pH is so important. What exactly IS soil pH?” In response,
the “expert” puffs himself up and says, “Well, pH is a measure of soil acidity!” The hunter exhibits the reaction
most common to such answers – a glassy-eyed stare. Sensing an opportunity to demonstrate his expertise, the
“expert” continues, “Well, let me try to put it in terms you can understand. pH is a measurement scale from 1-14,
with the lower numbers being more acidic and the higher more alkaline.”
Now, we deer hunters are loathe to show weakness in front of our buddies; and so rather than look even dumber
in front of his fellow hunters, the inquirer nods, says no more, and leaves not knowing any more than he did
before the encounter. The scenario didn’t have to end that way. The “expert” could have done the inquirer a
great service and probably locked in a customer to boot, had he been less concerned with his own image and
more with educating others.
So, what the heck IS soil pH? Or better yet, what does pH mean to us regular folk who are planning on planting a
food plot for deer?
For our purposes, soil pH is nothing more than an indicator of how well a plant can get nutrients out of the soil in
which it is growing. That’s it. It’s nothing more complicated than that. Plants are like any other living thing in that
they thrive in a limited range of environmental conditions. Different plants have different soil-pH ranges in which
they are best able to get nutrients out of the soil. Some plants, for example some garden ornamentals, do best in
relatively acidic soil, say a pH of 4-5. Not so with most deer-plot plants. The numbers vary a bit depending on
who you talk to, but generally most deer-plot plants are best able to get nutrients out of the soil when the pH is
around 6.5-7, which some refer to as “neutral pH.”
Here’s an analogy I came up with that I think defines soil pH well. Let’s say that you and I are seated at a table
piled high with nutritious food, but our jaws are wired shut. It wouldn’t matter how much food is on the table or
how nutritious it is; we’ll still starve because we can’t get the food into our bodies. Same thing with soil pH – you
and I are the plants, and the food on the table is fertilizer. Soil pH is the wire in the plants’ jaws, and the lower the
soil pH the tighter the wire.
So, if you had to pick which is more important, pH or fertilizer, it could be argued that pH is more important, since
with neutral pH, the plant can at least get whatever nutrients are already in the soil. Make sense? Of course, the
point is not to say that one should lime but not fertilize. Both soil pH and soil nutrient content are important and
should be addressed for best plot results.
So, what if the pH of the soil in which we are planting a plot is too low? The most common method for raising low
soil pH is the incorporation of granular or pelletized lime into the soil many months in advance of planting to give
the lime time to raise soil pH. But how do we know for SURE what our pH is, and therefore, how much lime we
have, or don’t have, to add? Simple – do a soil test. Yes, I know, soil testing is a big pain in the rear, right? Extra
money you don’t need to spend, right? And, even if pH is too low, one can compensate by adding excess
fertilizer, right? WRONG!
Listen carefully: Get a soil test – not a slurry kit or a probe, but the kind that requires you to dig up some dirt and
send it off to a lab, and get one for each plot you are planning on planting. Test kits generally cost around $10,
including the lab analysis fee. Chances are you will more than make that back in lime and fertilizer savings
compared to what you’ll have to apply to be sure you cover the bases without the test. Also, adding excess
fertilizer won’t make up for inadequate pH. Remember our earlier analogy – if soil pH is too low, it doesn’t matter
how much food is on the table (fertilizer is in the ground) because we (the plants) can’t get it into our bodies if
our jaws are wired shut (soil pH is too low).
The most important things the soil test will tell you are the pH of, and the phosphorous and potassium levels in,
your soil. With just that information, you can tailor the lime and fertilizer blend to reach adequate soil conditions.
If you have trouble reading your soil test results, call the company that made the plot mix. The company should
have a consultant readily available to help you understand the recommendations in the report. If you can’t get
them on the phone, or if they can’t help explain your soil test results to you, then next time buy from someone
who takes customer service seriously.
Soil test kits are available directly from The Whitetail Institute, ag universities, your local soil conservation service
and most farm supply stores. Again, be sure the kit you use requires that soil be sent to a lab for testing and is
not a probe or slurry-type kit. To order a high-quality soil test kit, or for more information, give our consultants a
call toll free anytime from 8 a.m. to 5 p.m. CST Monday through Friday at 800-688-3030, ext. 1.
"Reprinted with permission of the Whitetail Institute of North America.
For more info on this article and other related topics contact them at
(800) 688-3030 or visit their website at wwww.whitetailinstitute.com."