Designed to last three to five years, Whitetail Institute perennials can be the backbone of a food plot system. The three most important things you can do to get the most production and longevity from your perennials are liming low pH soil, fertilizing, and controlling weeds. Each of these is important in its own right. Moreover, cutting corners on one can also reduce your results with the others.
SOIL
PH AND LIME
It is often
said that aside from death and taxes, few things in life are certain. Folks who
think that way must not be food-plotters, because they are missing some things.
One is the fact that performing a laboratory soil test is the best way to
ensure two things: that your food plot planting will be the best it can be, and
that you do not spend more than you have to on lime and fertilizer. That is why
any proper discussion of lime and fertilizer requirements must include a
reminder of how important it is to have your soil tested through a qualified
soil-testing laboratory before you buy any lime or fertilizer. It is so
important that you will see this advice in nearly every issue of Whitetail
News.
Soil
Test to Assure Optimum Growth and SAVE MONEY!
Always have a
qualified soil-testing laboratory analyze your soil before you buy any lime or
fertilizer. That is the only way to find out exactly how much lime, and what
blend and how much fertilizer you need to buy so that your forage plants can
flourish, and you don’t waste money buying excess lime or fertilizer. Most
forage products come with general lime and fertilizer recommendations in their
planting instructions, but realize that these are default recommendations
designed to cover most situations in which a soil test is not available. Lime and
fertilizer requirements depend heavily on site-specific factors such as soil
type, though, so it’s likely that the default recommendations are not exactly
what your plot needs, which can result in you buying more or less of one or
more components than you really need. That’s why having your soil tested by a
qualified soil-testing laboratory is the closest thing there is in agriculture to
an investment with 100 percent or better guaranteed return, in many cases
saving you hundreds of dollars by avoiding wasted lime and fertilizer costs. High-quality
soil tests are available from the Whitetail Institute, agricultural university
extension offices and county agents. Make sure that whatever soil test kit you
use has the soil analyzed by a qualified soil-testing lab, and be sure to let
the lab know what the forage is, and whether you will be planting it or
maintaining it. That way, the lab can precisely tailor its recommendations.
SOIL
PH, LIME AND FERTILIZER
The most
important factor in assuring food plot success is making sure that the pH of
the soil in your plot is 6.5 or higher. Moreover, it might be a surprise to
some of you that soil pH is an extremely easy thing to understand.
What does “pH”
mean? pH is a statement of something’s acidity
or alkalinity. It is expressed as a number on a scale from 0 to 14. Lower
numbers indicate acidic pH, and higher numbers indicate alkaline pH. Some
common examples are shown in Graphic 1, below.
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| Graphic 1 |
The Simple
Matter of Soil pH: Soil pH is described
the same way — lower numbers indicate acidic soil, and higher numbers indicate alkaline
soil. When it comes to high-quality forages, a third set of numbers — from
about 6.5 to 7.5, described as the neutral pH range — are especially critical.
 |
| Graphic 2 |
Why is it
important to plant in soil with neutral soil pH? It
is important for the same reason it is important that we humans need to be able
to eat. If we do not eat enough nourishing food, our health suffers — and the
worse the nutritional shortfall is, the worse our health is. Pretty simple, right?
Well, guess what? That’s the same reason making sure your soil pH is at optimum
levels is so important for forage plants: Most high-quality forages are best
able to use the fertilizer we put out if they are growing in soil with a
neutral pH (about 6.5 to 7.5). And the lower the pH is from neutral, the less
fertilizer the plants can use. Let’s take a look at what that means. Let’s say
the soil pH in your plot is 5.0, and you just spent $100 on fertilizer and put
it out on your plot. Graphic 3 shows that a soil pH of 5.0 is strongly acidic,
which will restrict the amount of fertilizer the plants can get to only about
46 percent. That means you just wasted $54 — more than half the $100 you just
spent on fertilizer.
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| Graphic 3 |
Lime: When
you get your soil test report back from the lab, chances are that it will show
that your soil is acidic (that its soil pH is less than 6.5). By far, it’s most
common for fallow soils to be in the acidic range. Lime is used to increase
soil pH, so if the lab report shows that your soil is acidic, it will also give
you its recommendation for how much lime to add to the soil to raise your soil
pH to neutral. When soil pH is low, lime recommendations of two or three tons
per acre are not unusual, so it is a good thing that lime tends to be
relatively inexpensive. The reason so much lime is needed is because lime works
in particle- to-particle contact with the soil to raise soil pH. That’s also
why you should add any lime you need as far in advance of planting as possible
to give it more time to work, and why you should thoroughly disk or till it
into the top few inches of the seedbed so that it can work as quickly as
possible. The lime you should use for this purpose is crushed limestone rock, which
can be dolomitic or calcitic lime — either will be fine. The less expensive form
is aglime, which is comparatively coarsely ground limestone and often available
in bulk. You can also buy it in pelleted form, which consists of very finely
crushed limestone rolled up into little clay balls so that it will feed through
a broadcast spreader, but it’s more expensive.
Fertilizer: When
you have your soil pH adjusted so that your forage plants will be able to feed
themselves by uptaking nutrients from the soil, you will need to make sure that
soil nutrients are sufficient. Just like humans need good food to grow healthy
bodies, plants need specific nutrients to be healthy. Your soil test report
will also tell you how much and what blend of fertilizer you will need to add
to the seedbed when you plant. The three main nutrients you are concerned with
are nitrogen (N), phosphorous (P) and potassium (K). Your soil test will tell
you how much of each you’ll need. Many farm supply stores can custom blend N, P
and K according to your soil test report, and most also have pre-packaged
fertilizer blends that will cover most situations.
CONTROLLING
GRASS AND OTHER WEEDS
Remember the
old saying about death and taxes I mentioned earlier? Food plotters can count
on two more virtual certainties: No matter how well you prepare your seedbed,
grass and other weeds will show up again at some point, and if you don’t
control them in a timely manner, they can substantially reduce the quality and
longevity of the planting.
What’s in a
word? Weed can be defined as “any plant
that’s growing where we don’t want it.” When most of us discuss weed control in
everyday conversation, though, we tend to lump them into four categories based
on what they look like:
Grass .............................................................................Any
weed that looks like grass
Woody Weed................................Weeds
that have a hard stem such as briars
Vining Weeds...........Weeds
that grow along the ground instead of upright
Broadleaf Weeds...............................................A
catch-all for none of the above
Chemical Weed
Control: This basically means spraying a
herbicide solution. We will cover the basics of chemical weed control, but what
follows is not intended to be a complete discussion. To be sure you choose the right
herbicide for your intended use, always check the label on the herbicide. The
label is the only certain source of accurate information about what the
herbicide will control and what forage plants it won’t harm if used according
to directions, and how to mix, spray and dispose of the herbicide solution
correctly. Nonselective herbicides (herbicides that kill or damage any plants
that take them in) that are foliar uptake (enter a weed through its actively growing
leaf and don’t leave a presence in the soil) can be a great tool for removing
weeds from new plot sites that are heavily infested. Examples are
glyphosate-only herbicides from Monsanto (Roundup brand) and other
manufacturers. Herbicides suitable for controlling weeds in existing forage
stands are selective herbicides (designed to control weeds without harming
forage plants). Selective grass herbicides, such as the Whitetail Institute’s
Arrest, are often the best way to control or suppress most kinds of grass in
most perennial forage stands. Chemical control is the preferred method for
controlling most kinds of grass because most grasses tend to reproduce through
their roots, so mowing isn’t as effective for controlling grass as it is for
weeds that rely on flowering to reproduce. Arrest can be sprayed on existing
stands of any Imperial perennial, and on any other clover or alfalfa. Selective
broadleaf-weed herbicides, such as the Institute’s Slay product, are for
controlling many types of broadleaf weeds in existing stands of Imperial
Whitetail Clover, and any other clover or alfalfa.
Physical Weed
Control: This covers pretty much any action you
take to control weeds that isn’t a herbicide application. Examples are disking,
tilling, hand-pulling and mowing. Disking or tilling a new plot site at
two-week intervals a few times before planting can bring dormant weed seed in
the soil nearer the surface where it can germinate, and then be killed when the
plot is disked again two weeks later. This can substantially reduce the amount
of viable dormant seed in the soil. When the forage is growing, weeds can be
hand-pulled if there aren’t too many. Periodic mowing during spring and summer
can break the reseeding cycle of upright weeds that rely on flowering to
reproduce. And because it takes a lot of energy and nutrients out of forage
plants to flower, mowing to prevent your perennial forage plants from flowering
can also keep your forage plants as healthy, nutritious and growing as
vigorously as possible.
TYING
IT ALL TOGETHER
We’ve discussed
why liming low-pH soil, fertilizing and controlling weeds are important to
achieving our goal of having lush, thick perennial food plots that are highly
attractive and nutritious. Along the way, we also covered why you should
address all three and not cut corners on any of them. Here’s a summary:
1. The more
vigorous and healthy your perennial forage is, the better it can compete with
weeds. Here’s how Dr. Carroll Johnson, the
Whitetail Institute’s Weed and Herbicide Scientist, described this relationship
in an earlier Whitetail News article, titled “Integrated Weed Management” (available
online: use the search at www.whitetailinstitute.com) “Uniform crop growth is
the single most powerful form of weed control in any cropping system, including
food plots.” In the same article, Dr. Johnson went on to identify some of the
things that you need to address for growing conditions to be optimum for forage
health and weed control: “Forage selection, proper soil fertility (particularly
pH), seedbed preparation, seeding rate, and overall growing conditions are
cultural practices that provide weed control benefits of troublesome weeds.”
2. Liming
low-pH soil has two benefits. Your forage plants
must have access to sufficient nutrients if they are to grow and be healthy. If
you don’t lime first to raise low soil pH, the plants can’t uptake all the soil
nutrients they need. Dr. Johnson also mentioned in “Integrated Weed Management”
that “proper soil fertility (particularly pH)” is a significant factor in weed
control. Consider that many weeds grow best in fallow soils that are still in
their natural state, and that most fallow soils are naturally acidic. Liming
low-pH soils to raise soil pH to neutral actually makes it harder for some
weeds to grow and compete with your forage plants. So, cutting corners on lime
not only makes it harder for your forage plants to grow, but also doesn’t
inhibit weed growth as well.
3. Cutting
corners on lime or fertilizer reduces the benefit of both on forage health and
growth: Your forage plants must have access to
sufficient nutrients if they are to grow and be healthy. If you fertilize fully
but don’t lime first to raise low soil pH, plants won’t be able to use all the
fertilizer. And if you lime sufficiently to raise soil pH to neutral but don’t
correctly fertilize to raise insufficient soil nutrient levels, the plants
still can’t get all the nutrients they need. For your forage plants to get all
the nutrients they need, you should address both low soil pH and nutrient
levels.
4. Ground
tillage at two-week intervals a few times before planting can help incorporate
lime and also reduce weed competition. Earlier, we mentioned
that disking or tilling a new seedbed every two weeks a few times before
planting is a great way to reduce weed competition by “cleaning” the soil
(reducing levels of dormant weed seed). We also mentioned that lime should be
thoroughly disked or tilled into the soil to increase soil pH as quickly as
possible. So add any lime called for in your soil test report as early as
possible, and disk or till it into the top few inches of the seedbed.
5. Mowing can
help control weeds, keep perennials even more lush, attractive and nutritious
and stimulate forage growth. Periodic mowing during
the spring and summer can break the reseeding cycle of weeds that rely on
flowering to reproduce. Mowing also helps maximize forage quality in two ways.
First, it can prevent forage plants from expending the huge amounts of
nutrients and energy it takes them to flower. Second, like pruning a bush,
mowing can stimulate forage plants to put on new even more nutritious growth at
lower levels. So, don’t cut corners, especially on lime, fertilizer and weed
control. All must be addressed if your forage plants are to be as lush and
healthy, nutritious and grow as vigorously as they can. If you have any
questions or need additional information about the matters discussed in this
article, call the Whitetail Institute’s in-house consultants at (800) 688-3030.
