Habitat & Conservation  |  04/20/2017

On Being a Disk Artist

Field disks are pretty standard fare in farm country, even among wildlife landowners with limited tools to manage habitat.  Blunt weapons in the universe of farm equipment, disks have one basic job -- disturbing the soil.  They open the ground with brute force, turning growing vegetation under, incorporating crop residues, loosening soil and smoothing seed beds.  Disks emerge for field work mostly in the spring, but then lead lonely lives, sleeping in the shed or in the shade of an apple tree the rest of the year.  Instead, they should be out on the land having more fun, wreaking a little havoc to improve wildlife habitat.
In the arsenal of habitat practices, disking is uncomplicated, effective and comparatively inexpensive.  Safer than prescribed fire, and with different effects, it produces less anxiety.  Here the investment of a little time and tractor gas can gain you a lot.  Disking works by mechanically setting back or killing sod-bound perennial grasses and small diameter woody plants that choke out formerly productive grassland habitat.  It may seem counter-intuitive to destroy cover you established several years ago, but that’s exactly what’s needed…. and frequently. 
Opening the ground to sunlight allows annual grasses and broadleaved plants waiting in the soil’s seed bank to germinate.  With warmth and moisture, plant diversity explodes.  Early successional plants like common and giant ragweed, partridge pea, tick trefoil, lespedeza, sunflowers and foxtail produce abundant seed and plentiful browse for wildlife food and leafy material for cover.  Reducing plant litter increases bare ground so young pheasant and quail broods have easy access to protein-packed bugs (up to 4 times more insects in new growth) attracted by soft, succulent plants.  The high plant diversity also provides better nesting structure for a wide variety of grassland birds.  Wildlife beneficiaries include most small game along with songbirds, deer and more.

An annual investment

This is as an annual investment for better habitat.  If you are a budding disk artist, tear-up linear grass strips across old fields next to crops, shrub-infested fence rows, cool or warm season grasses and woodland edges.   You may have to mow, graze, hay or burn an area before strip disking if existing vegetation or litter is thick. Multiple passes may be needed.  Aim for about 50% -75% bare soil, and consider inter-seeding if you are short on legumes (peas, beans, alfalfa).  Run the length of the field in swaths from 25 to 50 feet wide, hugging land contours to reduce erosion, with the disk set low enough to kill most existing vegetation (a 4 inch setting usually works).
Leave a band of unmolested vegetation about twice as wide next to the disturbed strip (for nesting and roosting cover). This lets you set up a rotational pattern where a third of the total area is disked each year. Delay much longer and seed-producing annuals will decline, litter will accumulate and shrub woody seedlings will begin to invade. 
Disking tired, old grasslands can occur from fall through very early spring. Timing impact results.  Fall disturbance promotes broadleaves and legumes, while early spring disking stimulates annual grasses.  You’ll like the results – with four times the insect biomass of tired old vegetation, you’ll have happy broods and more of them.  No guarantees, but six-fold increases in quail coveys have been documented using just strip disking.   Strip disking provides more bugs and abundant natural seed at a low cost.  It belongs in your yearly playbook of habitat management, along with grain food plots and woody and nesting cover enhancement.
Story by Jim Wooley