Summer fallow long has been part of the deal western Nebraska dryland farmers strike to get enough moisture for winter wheat. It's no great bargain.

Summer fallow – idling land 10 to 14 months to build soil moisture – has economic and environmental drawbacks. Scientists at the University of Nebraska's Panhandle Research and Extension Center are exploring the feasibility of eliminating this long-standing practice.

Farming without fallow could open the gate for more intense cropping systems and more profit potential, said NU Agronomist Drew Lyon.

Today's reduced and no-till cropping systems allow farmers to capture and hold far more precipitation in soil when crops aren't growing than with conventional tillage. That makes it possible to summer fallow less frequently and to grow more crops.

A rotation of two crops in three years or three crops in four years is an option instead of just one crop in two years with fallow. Summer fallow still will play a part, but a smaller role as winter wheat acreage decreases, Lyon said.

Institute of Agriculture and Natural Resources researchers are exploring the next step – whether it's possible to eliminate summer fallow. Lyon and IANR Agronomists Jürg Blumenthal, David Baltensperger and Plant Pathologist Bob Harveson are field testing the possibility at the High Plains Agricultural Lab near Sidney and analyzing its profit potential.

Lyon is concentrating on whether it's possible to eliminate summer fallow – and not on crop rotation specifics – because reducing or eliminating fallow is a major issue.

"This will get producers more income from land they normally wouldn't farm," he said. "Over the long term, it will improve soil quality and reduce susceptibility to wind and water erosion."

Researchers are comparing winter wheat performance following chemical summer fallow with performance following five summer crops harvested from late June through mid-September before wheat planting. They're analyzing wheat yields, moisture availability and nitrogen needs.

The five spring-planted crops are an oat/pea mixture for forage, spring canola, proso millet, dry bean and corn. Test plots of each are planted in sunflower stubble preceding winter wheat. Sunflowers use lots of water so soil moisture is depleted going into the summer crop tests, Lyon said.

In two years of spring-planted crop trials, winter wheat performed best after proso millet or oat/pea for forage, Lyon said. Winter wheat yielded 20 percent to 25 percent more following summer fallow but summer crops may offset lower yields.

Economically, oat/pea for forage and proso millet offer equally profitable alternatives to summer fallow, said Research Analyst Paul Burgener, who's assessing economic feasibility. Corn, dry beans and canola will need additional plant breeding work, production improvements or economic incentives to profitably displace fallow.

"Before we can eliminate summer fallow, an alternate approach is needed that doesn't significantly jeopardize a healthy and productive winter wheat crop," Lyon said.

Wheat yields were similar despite having one wet summer and one dry summer, researchers found. Surprisingly, they also found little yield response to different nitrogen fertilizer levels in any crop, despite an assumption that more fertility is needed in dryland cropping systems without summer fallow.

The study wraps up late this year. Future research will explore additional and shorter-season crops as well as management practices.

The Anna Elliott Fund helps support this research.

– Sandi S. Alswager

To explore the feasibility of reducing or eliminating summer fallow in Nebraska's Panhandle, IANR scientists compare winter wheat's performance at different growth stages following summer fallow or different summer crops. On the left, winter wheat planted after fall corn harvest gets a late start, which results in reduced fall growth and smaller plants in spring. In the plot on the right, winter wheat planted earlier in the fall has more fall growth and a better stand come spring.