By Kent Kammermeyer
Certified Wildlife Biologist/Consultant
"Got lime?" This is my first question for the hunter on the phone who wants to know what to plant in his deer food plots. If the answer is "no," then my response to the caller switches to Plan B and we end up talking about lesser deer planting possibilities such as rye, ryegrass, wheat, crimson clover, or birdsfoot trefoil. Not bad plantings for deer, but not the quality or production of alfalfa, ladino clover, oats, red clover, grain sorghum or corn (which can't be grown effectively in low pH soils).
Photo: If lime trucks are not an option, pelletized bag lime is your alternative.
As a matter of fact, if the answer were "yes," then you could not only grow all the Plan A&B crops, you could come close to doubling their production in pounds/acre and greatly increase the protein and digestibility of these plants.
Lots of folks like to take shortcuts, travel the easy road and get it done fast. I was one of those when it came to deer plots, until I learned the hard way, 32 years ago, that we had to have lime to grow anything other than KY31 toxic fescue in our acidic food plots in northeast Georgia. Our soil tests were showing pH levels from 4.8 to 5.2 (extremely acid) and recommending three to five tons of dolomitic (also called agricultural lime because it contains both calcium and magnesium) limestone/acre!
Thirty two years later, they are still putting out over 400 tons of agricultural lime/year with two of their own lime trucks as needed on parts of the 900 acre food plot system on 14 WMAs. Each field gets soil tested at least once every three years in the mid-summer. They get results back from the University of Georgia extension service soil testing lab and follow their recommendations for liming. Actually, from experience and advice from retired agronomist Dr. Bill Sell (who supervised the soil testing lab), we put out a ton/acre more than the recommendations called for. If our test shows two tons needed, we apply three. The reasoning behind this is solid: instead of conservatively raising the pH to 6.0, the extra ton raises it all the way to 7.0 buying another one or two years that we did not have to haul lime to that plot. The interval between liming thus becomes four or five years instead of three.
There is no doubt in my mind that lime is the backbone of a perennial clover food plot program. Without it, most deer managers would be sunk. Why? Acidity is the number one soil problem in Georgia, the southeastern U.S. and the entire eastern U.S. Past loss of topsoil, native acidity of woodland soils, and intensive abuse of croplands have all contributed to increased soil acidity. Nitrogen fertilizers, crop removal, and the loss of calcium and magnesium by leaching all combine to push soil pH downward.
Photo: Lime spreader trucks are efficient and cost effective.
Why don't all farmers soil test and use adequate agricultural limestone? This is a great mystery. Agricultural lime is frequently called the biggest bargain available to farmers. Acidic soil conditions are a result of high hydrogen ion concentration in the soil. If allowed to remain, the soil cannot hold necessary nutrients and plants can't grow properly. Lime application causes hydrogen to be replaced by calcium and magnesium, which reduces the soil acidity. In turn, other tied up nutrients (such as phosphorus) can easily displace some of the calcium and magnesium on the soil particle and be held for plant use. Usually crops not requiring heavy applications of nitrogen can go three to five years between lime applications. As a rule, less lime is needed to raise soil pH in a sandy soil than in a clay soil but sandy soil requires more frequent applications because the elements leach downward faster.
Agricultural lime begins to raise pH immediately upon contact with acidic soil. However, a full reaction may take as long as from 12 to 24 months. Lime can be applied at any time of year, especially under dry spreading conditions and unbroken ground. Performance of lime is enhanced by application well in advance of the planting season. Another consideration: most lime is spread by fertilizer dealers who have more time to apply lime in the fall and winter. It is very important to incorporate lime into the top four to six inches of soil where it is available uniformly to the plant root systems. Lime does not move downward quickly in the soil profile.
Besides supplying calcium and magnesium which neutralizes soil acidity (increases soil pH), lime also promotes desirable bacterial activity in the soil, improves organic matter decomposition and increases the plant's ability to efficiently use major and minor fertilizer elements. Fertilizer without lime is about as effective as a deer rifle without bullets!
Liming tips include using a spreader truck wherever possible for convenience and economics. Truck spread lime costs $30-50 per ton versus pelletized bag lime costing $150 or more per ton plus labor to spread it in a fertilizer distributor. Have you ever put out two tons of lime/acre using 100 40-pounds bags of pelletized lime in a 250-pound fertilizer spreader? I have and it's no fun! I know hunters who do it with a four-wheeler pulling a 50-pound capacity fertilizer distributor or even shoveled or poured out of the back of a pickup truck. If it has to be, it has to be, but try your best to locate your plots so they are accessible by lime truck and big enough to be worth a trip (two acres or better usually equals a minimum of four tons of lime on an eight ton capacity truck). Treat your agricultural lime truck dealer like your best buddy by making every effort to avoid getting his truck stuck or breaking his side view mirrors on narrow pig trails!
A Word of Caution:
There is a product out there called liquid lime, often sold in 2 1/2- gallon jugs. There are some extravagant, exaggerated testimonials out there claiming that this product is so concentrated that it is the equivalent of thousands of pounds of powdered agricultural lime. It's not true! In actuality, a ton of liquid lime is roughly equivalent to a ton of powdered dolomitic lime. Don't waste your money on liquid lime, it is cost prohibitive to apply enough to correct soil pH over the long haul like agricultural lime surely does.
In summary, to get the most from your expensive seed and fertilizer (or even to get it to grow at all in many cases), apply lime according to the results of a soil test. In most cases I advise to apply even more lime than what is recommended. It will contribute to higher protein, higher production, better digestibility and directly to better antlers. Lime is calcium and along with phosphorus is a major component of deer antlers. Believe me, it is a far more important tool in your food plot bag than salt licks!