Will Disking Increase Bobwhite Abundance?
To increase quail numbers, the factor limiting their numbers must be identified and corrected. In most years and in most situations, plant food production is generally not the limiting factor. Thus, disking seldom increases bobwhite abundance because it does not address the issues that usually limit bobwhite numbers. However, food availability (e.g., the absence of quail cover or coverts near food sources) can limit quail numbers. Food availability can be limited by the lack of suitable cover, such as plum or other suitable shrubby thickets, or overabundant, dense stands of grass that prohibit or interfere with a quail's ability to forage.
Disking sets back succession by breaking down herbaceous vegetation and disturbing the soil. This process encourages lower successional forbs and grasses that produce seeds and greens and attract invertebrates for quail. Disking can improve feeding cover and food abundance, especially in areas dominated with plant thatch or grass sod. If applied correctly, the results may be a plethora of plants and insects that might be beneficial to quail. If applied incorrectly, soil erosion or an abundance of unwanted plants (weeds) may prevail. An astute manager should learn about the advantages and disadvantages disking may have on bobwhite and the landscape before application.
Areas selected for disking should have some desirable forbs (e.g. croton [Croton spp.], common sunflower [Helianthus annuus], western ragweed [Ambrosia psilostachya], etc.) present, not exceed 5 percent slope to reduce erosion, not have excessive rocks or stumps, be located within 50 yards of woody cover and be excluded from livestock, if necessary.
Generally, forb seeds are already in the soil, but the area to be disked should be inspected for desirable bobwhite food plants to enhance results and justify costs. Learn to identify key bobwhite food plants on your property and learn how to manage them. Often, quail foods can be stimulated with prescribed grazing management, especially on sandy soils or in drier climates. If not, prescribed fire or a light disking is usually all that's needed to stimulate many bobwhite food plants. Disking too deeply can bury seeds and reduce germination. February is a good time of the year to stimulate production of many quail food plants. Disking in late fall or early winter may increase the diversity of the responding plant community, but take care not to stimulate unwanted plants and destroy too much fall and winter cover and food. Disking in alternating strips is another way to increase plant diversity. This can be easily done by selecting an area three disk widths wide and disking one width each year, creating a three year rotation. The rotation may need to be more frequent in areas of higher rainfall where grasses tend to re-dominate disked areas more rapidly.
Disked fireguards and disking along fencerows or field borders are ways to incorporate tillage into your quail management plan. Disked areas should comprise enough area in the pasture to provide accessible food, but not so much to eliminate cover for nesting and escape. Research suggests that 5 to 10 percent of an area be in field borders to enhance bobwhite populations.
The practice of disking leaves the soil bare and exposed for a period of time, leading to soil erosion if not properly implemented. The risk of erosion is slight on soils with slopes less than 3 percent. On slopes from 3 to 5 percent, contour disking should be considered. Disking should not be done on slopes exceeding 5 percent.
Disking areas beyond 100 yards from cover is an exercise in futility. Food sources beyond 100 yards from cover are essentially unavailable to bobwhite and therefore are not useful. A manager can create an abundance of food, but if cover is not sufficient, the food is unavailable. Managers should strive to maintain adequate food (invertebrates and seeds) abundance and availability. Moisture is a critical factor in food abundance, especially in drier areas. Unfortunately, a manager can't control rainfall, but can control how the rainfall is used through soil and plant management. A manager also has control of food availability by creating a landscape conducive to producing abundant bobwhite food and providing cover to increase the availability of food to bobwhite.