Preparing a well producing food plot takes time, money, and sweat equity. The first two, most of us wish we had more of. So, ensuring that your efforts will be rewarded in a green lush plot this coming fall is the main goal and the first step to ensure your success is taking a soil sample. I'll even admit I've been guilty of disking up some bare dirt, throwing down some seed and fertilizer found at the local garden store and crossing my fingers. More often than not, I never got the results I was looking for.
Taking a soil sample is the easiest thing you can do to ensure proper growth of a food plot and not waste time and money. So why not do it? The equipment needed to complete a proper soil sample is quite inexpensive, and more than likely you already own them. You will need a spade or a shovel to take the core sample. You will also need a bucket to put your samples in. And finally you will need a plastic baggy to fill with your sample. Many soil analytic labs will provide a sample baggy and a form. We run our tests through Penn State College of Agricultural Sciences. At $9 a test, you won't find a better deal, it may be the cheapest investment you'll have in your plots.
Now, the biggest misconception of taking a soil sample is you can do one test for all the plots on your property. This is not true, you need a sample sent in for each individual plot you have, even if plot A is 100 yards over the hill from plot B. Each plot will need 8-12 core samples, depending on the size. These core samples should be randomly selected and get a good sampling of the entire plot.
Whether you are using a professional soil sampler or a shovel each core should reach a depth of 3-5 inches. Before placing the core into the bucket, remove the top organic layer or “duff layer”. Once you have gone around and collected all of your core samples. It is now time to mix the entire bucket together. Make sure the soil is dry, or you will have to spread out your collection and give it time to dry. Once mixed thoroughly, take approximately 1-2 cups of soil and fill the bag to the required fill line. Now make sure to label the baggy in correspondence with your records to know which sample goes with what food plot. Fill out the required form along with each sample, and make sure to attach that with your sample.
Once you receive your results, approximately 1 week later, it's time to take the recommendations and turn it into a plan. Each sample will be different and require different lime and fertilizer treatments. The first thing you will see is the soil's pH level. This is important because this regulates the amount of nutrients and chemicals that are soluble in soil water, and therefore the amount of nutrients available to plants. Having your soil a little more acidic (6.5) is where you want your soil to be.
The other main features of your soil test will be nutrient levels of Phosphorus (P), Potassium (K), Magnesium (Mg) and Calcium (Ca). Usually any soil test report will give some sort of visual chart that will showcase Below Optimum, Optimum and Above Optimum level for each of these nutrient values. Obviously you want to be at the Optimum level for each nutrient.
Recommendations for fertilizer will be reported as (N) Nitrogen, (P) Phosphorus and (K) Potassium. The recommendations will be reported as pounds per acre. Uniformly the levels on the bag of fertilizer will be expressed N P K. The numbers labeled for the NPK level are a percentage of weight in each bag of fertilizer. For example a 50lb bag of 10-20-20 will be formulated as 5lbs of Nitrogen, 10lbs of Phosphorus and 10lbs of Potassium. With a little math and the recommendations from the soil report, you will get the correct ratio of fertilizer. Depending on the forage you plan to plant, will also depend on what will be used as fertilizer. The only type of fertilizer that can be an issue is any fertilizer high in nitrogen content, 46-0-0 for example. This should not be applied to any type of forage that is a nitrogen fixator, such as clover. Nitrogen is not required because the plant will make its own nitrogen, and if you add extra nitrogen, the plant will not be able to stay stable and grow properly.
A couple other nutrients to pay attention to is Calcium (Ca) and Magnesium (Mg). These two nutrients will determine the type of lime to be used. If the Magnesium level is below optimal that means you will need a high mag lime. High mag lime is typically found as Pelletized lime. Now looking at Calcium levels, if it is lower you will need to apply a higher calcium lime. Calcium lime is typically found as AG/ Powdered lime or Hydrated lime. This goes to show that lime is not lime, there are some differences, more than just price and accessibility.
There is one other factor, probably the most important reading on the soil sample report, and it is rarely ever talked about in the food plotting industry. This reading that you need to pay special close attention to is the Cat-ion Exchange Capacity (CEC). The CEC of a soil determines the number of positively-charged ions, cations that the soil can hold. This, in turn, can have a significant effect on the fertility management of the soil. In simpler terms, the higher the number, the more fertile your soil is.
In what ways can you increase your soil fertility? The most efficient way to increase your soil fertility is by adding organic matter to the soil. Adding a thick or tall growing food plot when you're not worried about hunting over the plot, then terminating and tilling the plants into the ground is a very effective method to achieve an increase in the CEC. I recommend using AccuForage’s Spring King or Out of Sight. Both have been proven to increase the CEC.
Understanding the correct methodology based off of your soil samples gives you the edge to produce high quality and highly attractive food plots. These are beneficial to wildlife and will create some unreal hunting opportunities. I know you enjoy every minute you can be outside, especially now that you get to add some more time taking proper precautions and taking the needed soil samples.