Good food plots are a great tool to help deer reach their full antler growth and reproductive potential. However, a critical element to establishing a successful food plot is often overlooked by most land managers: soil moisture. This is probably the most elementary, yet important aspect of food plot production.
In 2006 soil moisture was less than optimum, as many regions of the eastern United States experienced below normal rainfall. With the exception of the Northeast and eastern Midwest, rainfall was less than optimum for May and June planting. Many land managers who delayed planting in May for hopes of rain in June were grimly greeted with even further reduced soil moisture. The lack of rainfall only intensified as the summer progressed into August, causing widespread extreme drought in the South and High Plains.
It's possible to produce a crop during a drought, but it won't provide the nutritional content or palatability of crops grown when normal amounts of precipitation are received because water is necessary to transfer soil nutrients to the plants. Drought further impacts the bacteria activity in the soil, which is vital to the growth of many plants. As a result, drought not only affects forage quality, but also a food plot's total yield. When food plots fail to germinate or produce palatable forage, deer utilize lower-quality vegetation for sustenance, lowering the number of fawns each doe can produce and reducing each buck's antler growth.
Even on food plot sites that maintain adequate moisture levels, such as low lying areas, drought has an impact. When high-quality forage is produced in a food plot surrounded by low-quality forage, over-browsing by deer will quickly occur within that food plot. This also occurs in native habitats but is sometimes less pronounced through the removal of low-nutritional twigs or leaves. We have found that these impacts can be lessened by planting annual food plots in drought prone areas. Typically, annual plant varieties utilize periods of adequate soil moisture for rapid growth, decreasing the overall loss of a crop during limited rainfall periods.
Dealing With Dry Conditions
Before planting it's important to test soil conditions to ensure seeds will rapidly germinate and begin to grow. Planting in soils with below-normal amounts of moisture will cause a large percentage of the seed to die as a result of desiccation, which is the drying out of seed to the degree that it's no longer viable. Remember that seeds are living organisms like us. Without adequate moisture their ability to survive is terminated. Even after germination, without continued adequate soil moisture the seedlings' energy reserves will be quickly depleted.
In regions experiencing consistent drought conditions, it's essential to add organic material to improve soil moisture retention. Organic material, such as poultry litter or the previous crop's vegetative growth, acts as a sponge and prevents moisture from quickly leaching through the soil. It further reduces evaporation by direct sunlight and blowing winds. The retention of even a small amount of moisture can be the difference between seed germination and desiccation, especially in sandy or thin soils.
Moisture loss is even further reduced when cultivation is minimized by planting with a no-till drill. The use of high-quality, efficient no-till drills allow food plot farmers to quickly and effectively plant areas that would normally be unproductive. The application of a herbicide to reduce existing weed competition during spring planting, and by drilling directly into the previous year's standing crop (especially corn and beans) prevents the wildlife's table from being wiped clean.
In addition to no-till drilling, broadcasting small seeded plants is also effective at minimizing soil moisture loss and maintaining forage appeal. Unlike drilling, however, broadcasting requires rainfall during or shortly after seeding. Without rainfall, seeds have limited soil contact and are vulnerable to a variety of environmental and biological problems. As noted earlier, desiccation is exacerbated when seeds are exposed to dry conditions. In addition, birds such as doves and turkeys can quickly remove a substantial amount of seed from local areas.
Rain impacts the soil surface in much the same way a cannon ball impacts a battlefield in historical documentaries. The impact acts to compact the soil while flinging soil particles into the air and settling them in a thin layer over a seed's surface. In the process, seeds are worked into fissures and indentations in the soil surface, serving to further increase seed-to-soil contact. In addition, the soil compaction by raindrops improves root growth by removing air pockets in the top portion of the soil's profile. Air pockets in the soil serve as barriers to root growth. This is especially important to newly germinating seeds that require their miniscule root system to efficiently gather vital nutrients for survival.
Realizing that rain is an important variable in the broadcasting equation, we waited through the end of August and into the beginning of September in 2006 for a forecast with a high percentage of rain before beginning to plant on our Missouri ranch. As the potential for rain increased, we quickly calibrated our broadcaster and set to work over-seeding the maturing BioMaxx food plots. After a few long days in the field, the job was complete—but the rains never came! A week and a half later, we finally received nearly a half-inch of rain. We impatiently monitored the food plots to see if the seed would germinate, but as we expected it was already too late and nearly nothing grew. We know we weren't alone as the U.S. Drought Monitor indicated the drought continued in many parts of the country through October. By that time, even in areas where rainfall lessened drought conditions, for most of the country the threat of frost was too imminent for replanting.
Planning For The Worst
You might now be asking, "Are food plots really worth the effort when drought is predicted?" The answer is "yes!" The most important aspect is to plant when conditions appear to be favorable for rapid germination. This is the best situation for a land manager to influence the outcome of their food plot because ultimately they must make a decision about if and when to plant.
Determining whether to plant can be less stressful if a back-up plan has been developed. Native vegetation that's locally adapted is almost always more drought tolerant than cultivated species that are bred for ideal growing conditions. We always recommend a large component of native forage management (forbs or weeds to most) in drought-prone areas to buffer against the herd-health swings due to total crop failure.
Implementing management techniques on native habitat such as burning, creating holes in the forest canopy and removing exotic vegetation will serve to free-up sunlight and nutrient resources for the beneficial growth of grasses, forbs and legumes. The abundance of high-quality, drought-resistant native forage is critical to the production of big bucks in South Texas, the Western prairie states and everywhere else whitetails thrive.