When is the best time for a soil test? The answer to such a broad question is easy: Perform a laboratory soil test any time you want to make sure your food plots have the opportunity to perform their best. If you’re asking more specifically about timing soil testing during a specific process such as seedbed preparation and perennial food plot maintenance, the answers are different, at least if you expect optimum results.
Perform a Laboratory Soil Test to Be Sure that Your Food Plots Will Have Unrestricted Access to Essential Soil-supplied Nutrients
Your immediate reaction
to the heading above might be, “When wouldn’t I want to be sure that my food plot
planting has unrestricted access to all the essential nutrients it needs?” If
that’s your response, then good for you. It shows that you’re already thinking
in terms of getting maximum performance from your food plot plantings by making
the soil as fertile as you can. Fortunately, most food plotters think that way.
Unfortunately, though, some still don’t. They cut corners on soil pH,
soil-supplied nutrients, and their food plots and hunting suffer as a result. The interdependence of soil pH and soil-supplied
nutrient levels is arguably the most important thing to understand and address
if you’re going to ensure food plot success. Most of us have heard the term
soil fertility, but do you know what it really means? Soil fertility describes
the quality of soil as a medium for growing plants, and it is determined by a
host of variable soil conditions. Some of these conditions can be determined
visually, such as if the soil contains substantial levels of organic matter,
how well or poorly it drains, and whether it’s compacted or well aerated. Other conditions, though, cannot be determined
visually and must be calculated through scientific analysis of the soil. Two
extremely important factors are in this category: nutrient levels in the soil,
and soil pH. The need for optimum levels
of essential nutrients in the soil is obvious; like all living things, plants
need to take in essential nutrition if they are to grow and flourish. Less
obvious, though, is the role soil pH plays in the ability of plants to access
nutrients in the soil. Most high-quality food plot plantings can only freely
access nutrients in the soil when soil pH is within “neutral” range (6.5-7.5).
Most fallow soils, though, are acidic (soil pH below 6.5), a condition that
restricts the availability of soil nutrients to the growing plants. While it’s important to make sure
soil-supplied nutrient levels and soil pH are within optimum range before
planting, making sure soil pH is neutral is the more important, since without
that, the plants can’t access all the nutrients they need from the soil anyway.
Adding more fertilizer won’t fix the problem, and it wastes even more money.
Adding lime to the seedbed removes the restrictions so plants can freely access
the needed nutrients. That’s why soil pH is the most important factor you can
control to ensure food plot success. It can make the difference between the
best food plot you can imagine and total failure.
The Case for Laboratory Soil Test Kits
Precision! Let’s
summarize some of the main things that make laboratory soil test kits the only
way to go for folks who want to ensure optimum food plot growth and not waste
money taking a shotgun approach to buying lime or fertilizer: •As we discussed earlier, soil pH and soil
nutrient levels as factors in soil fertility • are widely variable and • cannot be visibly determined. •Soils also differ widely in their capacities
to react to and maintain the effects of lime and fertilizer Once you take all that into account, you can
see that the only practical way to tell exactly what the soil pH and levels of
essential nutrients in your soil are and, if any levels are deficient, how to
determine the exact lime and/or fertilizer requirements to bring deficient
levels to optimum is to have a qualified soil-testing laboratory scientifically
analyze a sample of your soil. Next,
we’ll look at when to perform a laboratory soil test as a matter of timing,
based on whether you’ve prepared the seedbed for planting or maintaining an
existing perennial stand.
Timing the Laboratory Soil Test During Seedbed Preparation and Perennial Forage Maintenance
The Whitetail Institute
publishes seedbed preparation and planting instructions for each of its food
plot products, and forage-maintenance guidelines for each of its perennial
products. You can find them on the back of the product bags and at
whitetailinstitute.com. While the instructions and guidelines aren’t identical
for all Whitetail Institute food plot products, they do all have one thing in common:
they all recommend that the seedbed be limed and fertilized according to a
laboratory soil test.
The seedbed preparation
instructions recommend that the soil test be performed several months in
advance of planting if possible. That’s because fallow soils are most commonly
acidic, and lime doesn’t raise soil pH overnight. Lots of variables affect how
quickly lime works, such as characteristics of the soil, the form of the lime
used, whether or not the lime is incorporated (disked or tilled) into the soil
and, if so, how thoroughly. In all but the rarest cases, though, performing a
laboratory soil test and incorporating any lime recommended in the lab’s
report several months in advance of planting is sufficient time to allow soil
pH to rise enough by the time your planting dates arrive. A quick note about timing fertilization: Keep
in mind that here we’re talking about liming as part of seedbed preparation.
While lime should be worked into the soil by disking or tilling, and preferably
several months in advance of planting if possible, fertilizer should be put out
just prior to when you plant the seeds. This is reflected in the planting
instructions for each Whitetail Institute food plot product.
Soil Testing as Part of Perennial Forage Maintenance
The Whitetail Institute’s
maintenance recommendations for its perennial forages also suggest that a
laboratory soil test be performed every year or two to monitor soil pH and
fertility. However, there is no recommendation that the test be performed
several months in advance of when you plant to add any lime or fertilizer to
the standing forage. The reason is that it is assumed that the seedbed
instructions have been followed prior to planting, including raising soil pH to
neutral. Over time, naturally acidic
soil will move back toward an acidic condition due to a wide variety of causes
such as decomposition of organic matter, growing crops, and the application of
certain fertilizers. Generally speaking, naturally acidic soil that has been
adjusted to neutral soil pH tends to return to acidity from the surface down.
Top-dressing the seedbed with lime every year or two can help slow the rate at
which the soil pH returns to its natural level.
For best results,
eliminate all the negative variables you can. A laboratory soil test kit is the
best tool for doing that. As is the case with most of life’s endeavors, our
odds of success with food plots are maximized when we leave as little as
possible to chance. The good news is that with Whitetail Institute food plot
products, it’s easy to eliminate as many negative variables as possible. Just
follow the planting dates, and seedbed preparation and planting instructions
for each Whitetail Institute food plot product, and the maintenance
instructions for Whitetail Institute perennials. That includes performing
laboratory soil tests anytime you’re considering buying lime and/or fertilizer,
and a few months early if possible if you’re testing the soil as part of
seedbed prep for a new plot.
