For years folks have preached that “we can’t grow big deer because we have poor soils.” According to Natural Resources Management Regional Extension Agent Jordan Graves, this ideology has recently been challenged by a number of Certified Wildlife Biologists. Dr. Craig Harper (University of Tennessee) and Dr. Marcus Lashley (Mississippi State University) along with several of their associates set out to study the effect of soil quality on deer forage. Many folks believe that poor quality soils result in less quality deer. This leads folks in areas with low quality soils to spend their money on amending soils and expensive seed blends for food plots, as well as pouring money into feeders and expensive pelletized feed. Harper & Lashley’s study indicates this might not be necessary. Rather, they suggest someone could spend the same time, energy, and money promoting native vegetation and have similar or better results.
In their research, samples from multiple species of known deer-preferred plants were collected and sent to a lab for nutritional analysis. The biologists made sure to take the same parts of the plants that deer typically browse, which are younger smaller leaves and shoots toward the ends of the plants. These are known to be the most nutritional parts of each plant. They then took a soil sample from directly below each plant and sent them off for analysis. These collections were obtained from a number of sites across several states from North Carolina to Oklahoma. Sites were specifically selected based upon the variation of soil quality so the researchers could compare the nutritional content of plants in very poor quality soils to very high quality soils.
The results showed no correlation between the nutritional quality of a plant and the quality of the soil in which it was growing. The nutritional content of each plant sample was directly related to the plant species. Soil quality did have an effect on plant growth, specifically the biomass/volume each individual plant produced. Plants in better quality soil had similar nutritional content as plants in lesser soils, but they did notice the better soils produced larger individual plants. Rainfall also played a role in the biomass production of each plant.
So what nutrition do deer actually need? Several studies have led biologists to conclude that lactating does and bucks growing antlers during the warm months require a diet of 16% protein. Growing fawns require slightly higher, 19% protein diets. Several plant species tested during this study fulfilled those requirements regardless of the soil quality. Pokeweed and common ragweed being two of several that met protein requirements across all sites. The takeaway message is to manage your native vegetation in coordination with other management efforts to better your deer herd, regardless of your soil quality. This may mean increasing harvest to decrease competition between deer and allow more forage for remaining deer. You may even see better results with less money spent by manipulating native vegetation rather than trying to cultivate specific food plots or emptying your pockets into a deer feeder. For more information on which native plants are most beneficial and preferred by whitetail deer and the management techniques to promote them, contact Extension Agent Jordan Graves (Jordan.email@example.com or Cell 334-672-4826) or the Chambers Extension Office (334-864-9373).