Buckmasters Magazine

Why do so many hunters skip a $12 test when it’s a critical part of a successful food plot?

You’ve heard it time and time again: Test your soil before you drop the first seed or buy a bag of lime or fertilizer. It’s good advice, but it’s advice many food plotters fail to follow. That’s too bad. A $12 soil test can save you hundreds of dollars in fertilizer costs.

“Instead of putting down a bunch of fertilizer you might not need, a soil test can tell you exactly what will help your plants grow to their fullest potential,” said Whitetail Institute director of special projects Jon Cooner. “It’s one of the biggest mistakes I see, but it’s also one of the easiest to prevent.”

Excess fertilizer isn’t just a waste of money, it’s harmful to the environment. What isn’t used by plants often ends up in streams, lakes and rivers and creates algae blooms and other harmful side effects.

SOIL TESTS DEFINED

A soil test is a simple process that provides a scientific analysis of the pH, or acidity level, and the nutrients within the soil. There are do-it-yourself kits available at home-and-garden centers, but they can be unreliable and inaccurate. That’s why dedicated food plotters rely on a professional soil tests conducted by a lab that specializes in agronomy. There will be no question the data and recommendations provided will be precise.

“Good hunters require good information,” said Pennington Seed expert John Carpenter. “You would never head out to the woods without checking a weather report or taking into account the conditions you’ll be hunting in. The same thought process should apply to planting a food plot. You should never plant a seed until you know what the soil needs to help that plant succeed.”

Soil tests kits are available from local agriculture extension offices and through various private companies, including Whitetail Institute. In most cases, you’ll receive either a bag or box for the dirt, along with a form that asks some basic questions. Cooner says the lab will want to know what plant or plants you are growing and whether or not the test is for a new plot or an existing one. New plants often need different doses of fertilizer to give them a good start, while existing plots require pinpoint nutrient applications. In most cases, a single sample can give you accurate information for even a large plot, but occasionally, you might need multiple tests for one field.

“If there are obvious differences in soil types within a single large food plot, it’s a good idea to conduct different tests for each soil type,” says Cooner. “Most of the time, a single test is sufficient.”

That doesn’t mean you can scoop a fistful of dirt from one hole, toss it into the bag and send it off. A proper soil test needs to be a representative sample of the entire plot, no matter how large or small. Cooner typically takes between a dozen and 20 plugs, even more on larger plots, and mixes them in a clean container. A plug is usually about an inch in diameter and 3 inches deep. Contrary to popular belief, each plug should include the surface soil, not just dirt from 3 inches under the surface. In fact, that’s one of the biggest mistakes many hunters make, says Cooner.

“Nutrients work their way from the surface down to the roots,” he said. “In some cases, plant roots are at or just below the surface.”

Cooner recommends removing the plant matter and thoroughly mixing the dirt so the sample is a uniform blend. Then scoop about two cups from the bucket into the test kit bag, fill out the necessary information and drop it in the mail. It’s that simple.

The dirt sample is sent to either a private laboratory or a soil science lab at a state university, where it is put through a careful set of procedures. The dirt is dried, crushed and sifted. Technicians then add a solution of chemicals and distilled water to create a reaction with the soil’s acids. An electronic probe measures the pH level.

A separate test is used to determine soil nutrients. Samples are placed in a machine known as an inductively coupled plasma atomic emission spectrometer, or ICP. It calculates nitrogen (N), phosphorous (P), potassium (K) and at least a half-dozen other elements. The machine is entirely automated and figures data in about one minute, says Virginia Tech Soil Testing Lab director Steve Heckendorn.

“If all the machines are working properly and we don’t run into any other snags, we can process about 600 soil samples in a typical day,” he says.

In most cases, the test results are mailed, but Whitetail Institute and some other soil test companies can also send results and recommendations via e-mail.

FOLLOW THE DIRECTIONS

While some farmers need to know the abundance of other minerals, food plotters just need to know four basic things: nitrogen, phosphorous, potassium and pH level. With that knowledge, a hunter can grow everything from clover and brassicas to peas and wheat.

Whitetail Institute’s results will not only include recommended fertilization and lime rates at pounds per acre, they also offer rates based on a thousand-square-foot ratio. Either way, you’ll have to do some basic math to figure out exactly how many bags to buy or how much to order from your local farm service company. Larger applications are best administered in bulk, mostly because it’s much cheaper than bagged fertilizer, at least in large quantities.

Cooner says farm supply stores in rural regions often keep the three primary fertilizers (N, P and K) in separate bulk batches so they can mix fertilizers at specific rates. All you have to do is tell them the acreage and how many pounds per acre are recommended. They’ll take it from there.

If that’s not an option, you’ll have to buy pre-mixed bags that probably won’t be the exact ratios you need. That’s okay. In their test results, Whitetail Institute and some other labs offer recommended applications of various commercially available bagged fertilizers. For instance, if your plot needs 15 pounds of nitrogen and 120 pounds each of phosphorous and potassium per acre, the results include a chart that tells you exactly what to buy. In this case, it recommends 150 pounds of 10-10-10 per acre and 525 pounds of 0-0-20 per acre. It also breaks down those numbers for thousand-square-foot sections. And if those specific fertilizers aren’t available, the chart typically includes four or five other fertilizer combinations.

“Bagged fertilizers might not get you to the exact recommendations, but they are usually pretty close,” says Cooner. “If that’s all you have, it’s a pretty good option.”

START EARLY

Whatever you choose, it’s a good idea to amend the soil before the first seeds are planted. Lime can take up to six months to fully change the pH level, although disking it into the soil can speed the process. Cooner says it’s smart to fertilize the soil prior to planting, also. Putting fertilizer directly on seed can, in some cases, burn the sprouts as they emerge.

“Fertilize a week or so before you plant. Nitrogen only stays in the soil for about 30 to 45 days, so if you wait too long, that nitrogen will be gone,” he notes.

Once you get the soil right and the seed down, all you have to do is sit back and watch your plots grow. Nature will do the rest, but it will certainly do it better if you conduct a soil test and follow the recommendations.

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