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High Plains conservationists are finding new ways to integrate wildlife habitat into millions of acres of wheat-fallow cropland. Delayed minimum-till (DMT) is a new concept that shows so much promise for pheasants and other wildlife that the states of Kansas, Colorado, Nebraska and Wyoming — as well as Pheasants Forever and other partners — have recently launched promotions to encourage farmers to use the practice.

The DMT concept emerged from the cooperation of Randy Rodgers, a wildlife biologist with the Kansas Department of Wildlife and Parks (KDWP), and Alan Schlegel, an agronomist with Kansas State University. Wheat-fallow runs on a two-year cycle, skipping a planting season to allow moisture to rebuild in the soil before re-planting. Moisture conservation is the key to successful farming on the semi-arid High Plains.

Many farmers in the 17 states and two Canadian provinces where wheat-fallow is used once allowed weeds to grow after harvest in their 12-20 inch wheat stubble. This tall, weedy stubble provided is not only remarkable pheasant brood cover and winter habitat, but also provides waste grain and wild seed for other wildlife. The only downside to this old system, from a pheasant's perspective, was the weed control tillage in the spring of the fallow phase, which destroyed some nesting birds, eggs and young.

A time of change

In the late 1970s and '80s, many High Plains farmers began using herbicides to control weeds. Farmers sprayed immediately after harvest in late June or July, preventing summer growth of the broad-leaved plants necessary for pheasant brood and winter cover. Farmers also began spraying newly-developed sulfonylurea herbicides on green wheat in spring. The residual activity of the herbicides further minimized broad-leaved plant growth in the stubble.

By the 1990s, weedy stubble on the High Plains was rare and pheasant numbers had crashed. While many Conservation Reserve Program (CRP) acres had been added on the central High Plains by this time, Rodgers found that pheasants used CRP only 1/3 as much as weedy stubble. (CRP must be disturbed every 3-5 years to maximize pheasant use — a management tool PF is promoting).

Pheasants and other wildlife were further hurt when semi-dwarf varieties of wheat became popular on the High Plains. Shorter varieties resisted lodging (falling over) caused by wet or windy conditions better than taller wheat. Also, powerful modern combines allowed farmers to lower the headers to cut wheat on shorter side shoots or tillers. The upshot: shorter stubble equals poor quality wildlife habitat.

A new idea

The dramatic changes in High Plains farming practices and the resulting loss of wildlife motivated Rodgers to contact Schlegel and propose an investigation of DMT as an option to benefit wheat farmers and wildlife.

Schlegel conducted a six-year study at the KSU Southwest Research and Extension Center near Tribune, Kansas. He compared three wheat-fallow systems.

First, the conventional system used subtillage (cutting weeds below the surface using an undercutter) to control weeds throughout the 14-month fallow period. Second, the no-till system used herbicides for fallow weed control. And third in the DMT system, weeds were permitted to grow between harvest and frost. The new weed growth was sprayed once in spring. Any subsequent weed growth in the DMT system was controlled with subtillage.

What the research showed was exciting: farmers can actually increase their profits in wheat-fallow by allowing weeds to grow in stubble after harvest. The reasons DMT increases profitability are its low cost and its ability to conserve moisture.

When Troy Dumler, Kansas State University ag economist, compared the yields, inputs, and gross returns, it turned out that the DMT system provided an average net return of $39 per acre, compared to $30 per acre with the no-till system, and just $3 per acre with the conventional wheat-fallow system.

Keep in mind there is only one crop every two years in wheat-fallow. The most obvious conclusion of this work was that the post-harvest tillage used in conventional wheat-fallow was really harmful to grain yields and subsequent profit. The greatest drawback to the no-till system was the high cost of multiple herbicide applications throughout the 14-month fallow period.

Applied over 1,000 acres, for example, the DMT system would provide an increase in profits of $9,000 over the no-till wheat-fallow system. More impressively, DMT would increase profits by $36,000 over the conventional wheat-fallow system.

"This is an average and these increases may not happen every year. But in a lot of cases, that's the difference between a farmer making money in a year or losing it," Rodgers said.

Water is the key

The foundations of DMT's appeal are its low input costs and moisture building ability. Moisture is the crucial limiting factor in dryland wheat farming on the High Plains.

Dryland wheat is just that — there is no irrigation. Rodgers agrees that letting weeds grow after wheat harvest in the DMT system uses some of the moisture remaining in the soil.

However, the increased surface residue provided by the weeds and their upright structure help to significantly increase snow capture and retention over winter. Studies have shown that moisture from snow is responsible for up to 45 percent of wheat yields on the High Plains.

By using a herbicide for spring weed control in the fallow phase of the DMT system, all that upright residue is maintained on the soil surface during the critical spring months when the potential for soil moisture storage is typically greatest.

The heavy residue also reduces evaporation at ground level by preventing air movement and shading the soil. In this way, the DMT system more than makes up for the moisture used by weed growth after harvest.

Schlegel's agronomic research showed that, by the end of fallow, the DMT system stored an average of just over an inch more moisture in the soil compared to conventional wheat-fallow, and this despite the post-harvest water losses to weeds. While no-till wheat-fallow stored more moisture than DMT, it was less profitable due to higher input costs — i.e. increased herbicide costs.

A pheasant's perspective

From a pheasant's perspective, DMT offers many advantages. The post-harvest broad-leaved weed growth provides excellent brood cover and the weedy stubble makes good winter cover later on. The best combination for pheasants is found when both tall stubble and broad-leaved weeds are present. Rodgers found pheasants were six-times more abundant during winter in weedy stubble than in herbicide-sprayed stubble.

Yet, spraying can be a positive for pheasants come spring. Using herbicides for spring weed control, instead of tillage, in fallow stubble will allow most nests to survive. If tillage is used, substantial nest destruction is likely. Rodgers recommends subtillage once weeds begin to come on again in late June or July. Research he conducted in the early 80's showed that pheasant chicks and nests will often survive subtillage with an undercutter (without treaders), but virtually never survive surface tillage with a disk.

Also, pheasants aren't the only wildlife to benefit from DMT. Other species that benefit include cottontails, mule deer and many songbirds. Compared to conventional wheat-fallow, DMT also reduces soil erosion. The added residue and reduced tillage can increase soil organic matter and improve soil structure — all important for future crops.

Tall stubble benefits

Taller stubble should be part of the recipe as well. The DMT system, as with any High Plains crop rotation, works best when wheat stubble is kept as tall as possible. Like the added residue provided by the weeds, taller wheat stubble improves snow catch and decreases evaporation from the soil.

Rodgers has observed that taller stubble encourages growth of relatively benign broad-leaved weeds like wild sunflower. But short stubble tends to favor difficult-to-control grasses as well as Russian thistle. Of course, what happens in any particular field depends on the weather that year, soil type, seed bank, and past management practices.

Recent studies by scientists with the U.S. Department of Agriculture's (USDA) Agricultural Research Service indicated that farmers should always strive to cut wheat no less than 2/3 of the height to the base of the primary wheat stalk with conventional combine headers. This provides for optimum harvest efficiency, moisture conservation and erosion control.

KSU agricultural engineer Mark Schrock has pointed out that running the combine header too low carries the risk of decreasing the machine's threshing efficiency. This loss can offset the small amount of low quality grain gleaned from short tillers. Using a stripper header, which harvests grain without cutting the wheat stalk, may be even better, particularly if wheat is relatively short or thin.

DMT is catching on

	DMT in detail
	Pheasants Forever For more details on delayed minimum tillage (DMT), the free brochure "Improving Profit and Habitat in the Wheat-Fallow Rotation" is available from Randy Rodgers, Kansas Department of Wildlife & Parks, P.O. Box 338, Hays, KS 67601; or email your request to randyr@wp.state.ks.us; or call 785-628-8614.

With the research just completed, several states are beginning efforts to promote the DMT concept.

… in Kansas

The KDWP has recently incorporated DMT information into a video and has provided it, and supporting information, to all county ag extension agents in western Kansas. On top of that, KDWP has sent the video to every landowner and farm operator in the four-county pilot area of the Western Kansas Pheasant Initiative. Rodgers realizes DMT wheat-fallow won't work for everybody in western Kansas. Many farmers have shifted into more-intensive cropping rotations that require post-harvest weed control. But he thinks DMT will work well for High Plains farmers who are staying with wheat-fallow.

… in Nebraska

DMT has already gained a foothold in Nebraska's dry, western panhandle. There, the Nebraska Game and Parks Commission (NGPC) along with Pheasants Forever, the state's natural resources districts, and the federal Natural Resources Conservation Service are promoting DMT as part of the new Tall Wheat Stubble Management (WSM) Pilot Program. In fact, PF-Nebraska and the NGPC have jointly hired a biologist to promote this program.

Ritch Nelson, NGPC district habitat manager, said the WSM program began just last fall has already enrolled 1,400 acres, with most choosing a tall stubble-DMT option. Nelson said he expects the incentive program, which includes public hunting access, will be expanded beyond the Panhandle.

Nelson hopes the WSM program gains momentum and more people sign on. If that happens, he hopes the USDA may eventually consider including WSM as a conservation option in the Farm Bill.

&in Colorado

Tim Davis, private lands/real estate supervisor for the Colorado Division of Wildlife (CDOW), reports his agency is working toward offering incentives for DMT and tall stubble through the USDA's Environmental Quality Incentive Program (EQIP).

"We're hoping it will be more than a pilot program. It is a good way to provide multi-purpose benefits," Davis said.

Davis thinks the economic benefits are the main reason that farmers should try DMT, but he mentioned another reason. "We're currently in one of the worst droughts in history. If ever a practice that prevented soil moisture loss were to be implemented, this would be the time. DMT could be considered the dryland wheat farmer's insurance policy against drought."

Davis said CDOW's Pheasant Habitat Incentive Program (PHIP) and DMT are a perfect match. PHIP is administered in the field by Colorado's Pheasants Forever chapters. He said PF chapters are excited and ready to assist with promoting DMT in eastern Colorado's wheat country.

Bruce Rosenbach, habitat chairman Phillips County Chapter, lives in northeastern Colorado where he farms 2,500 acres of wheat. He said DMT will come close to paying for itself just on the basis of fuel savings because of the recent high price of diesel.

"I had 320 acres in DMT last year and will do 800 acres this year. It should help the pheasants because the hens like to nest in the weedy wheat stubble. It will be one more piece of the puzzle for pheasants," Rosenbach said.

&in Wyoming

In eastern Wyoming, Ryan Amundson, habitat extension biologist for the Wyoming Game and Fish Department, has also begun promoting DMT. The effort so far has mainly been an educational drive, but the state is also offering some limited, one-time incentives to coax farmers into increasing stubble height and trying DMT.

DMT in the future

Barth Crouch, Pheasants Forever wildlife biologist for Kansas, said he likes the new approach. "DMT holds a lot of promise for us. When it snows in Kansas, it often comes with a lot of wind. Anywhere there is CRP, there's no snow on the road — the plants hold the snow. DMT works the same. And when it rains, covered ground holds more water than bare ground or short stubble."

Crouch believes DMT incentives should be added to the federal Farm Bill. "Anything that keeps soil from blowing away and conserves moisture on the arid High Plains is good. We have to find new systems where the farmer makes money and we get wildlife too. That's the wave of the future."

Material from Pheasants Forever.
Visit the web site at www.pheasantsforever.org