By: Wayne Hanna
If you’re like most of us, you don’t have extra money to throw away. Even so,
that’s what some people do when they don’t test the soil in their food plots
before buying lime and fertilizer. In fact, having your soil test done through a
reputable soil-testing laboratory might not only be the best way to ensure
success with your food plots but save a lot of money as well.
Use a soil-test kit that sends the soil to a laboratory
for analysis: As the old saying goes, “An ounce of prevention is better
than a pound of cure,” and in this case, that ounce of prevention is to perform
a proper soil test through a lab. Cheap, do-it-yourself slurry or probe testers
cannot tell you exactly how much lime to add in a given situation, and most
don’t measure soil nutrient levels or recommend fertilizers. If you want to
eliminate waste from your lime and fertilizer budget, the only way is to know
exactly how much lime you need, what blend of fertilizer, and how much of it to
apply. High quality soil-test kits are available through most farm supply
stores, agricultural universities, county agents and the Whitetail
Institute.
When to test your soil: If possible, try to test your soil several months before planting. That will give your lime time to increase soil pH. Also, lime and fertilizer are getting more expensive, so test your soil not only before you plant but any time you are considering buying lime and fertilizer for an established field if you want to avoid spending more than you really need to.
Taking the soil sample: Keep in mind that you will
only be sending in about one pound of dirt, and that pound of dirt must
represent all the soil in the plot in which the forage plants will be growing.
Use one soil-test kit per plot location, even if two plots are close to each
other. It is amazing how widely varied soils can be even in the same general
area.
Using a shovel or trowel, take soil from one to six inches deep
and put the soil into a clean container. Then, repeat at 10 to 20 locations
around the site. After you have placed all the soil into the container,
thoroughly mix them together and put about a pint of the composite sample into
the soil-test pouch. Be sure to thoroughly and accurately complete the
information requested on the sample sheet and soil pouch. The accuracy of the
lab’s recommendations depends on it. Three of the most important items of
information you need to provide are the name of the plot the sample came from,
the forage you will be planting or maintaining, and whether you want a
recommendation for “establishment” (to plant the forage) or “maintenance” (of an
existing planting).
The
Whitetail Institute soil-test kit also includes a pre-addressed envelope for you
to use to mail your sample to their lab. If you will be testing more than one
plot, it can be a good idea to seal each soil pouch and completed sample sheet
in its own envelope and ship them together in the same box. That way, you’ll
know that all the samples arrived at the lab and that they arrived at the same
time.
Reading the soil-testing laboratory report: The two most important
things your soil-test report will tell you relate to soil pH and nutrient
levels. You should address both soil pH and nutrient levels if the plants are to
grow optimally. The Whitetail Institute soil-test report will tell you whether
you need to add lime to increase soil pH, and if so, how much. It will also tell
you exactly how much nitrogen (N), phosphorous (P) and potassium (K) you might
need to add, and it will provide alternative fertilizers based on commonly
available blends. If you can’t find any of the recommended blends, you can
usually come pretty close with a combination of available fertilizers if you
know what the numbers separated by dashes on the front of blended fertilizer
bags mean. In order from left to right, they represent the percentage of N, P
and K in the bag. For example, a fertilizer labeled as “5-10-15” is 5 percent N,
10 percent P and 15 percent K. That means 100 pounds of that blend would contain
5 pounds of N, 10 pounds of P and 15 pounds of K.
Remember, if you want
to avoid excess expenditures when planting a new forage or maintaining an
existing one, it's important to test your soil through a reputable soil-testing
laboratory anytime you are considering buying lime or fertilizer. And be sure to
provide the information requested on the submission form and soil pouch as
accurately and completely as possible.
