A team of researchers at the University of Nebraska have spent the last few years taking a look at why producers only use 25% of the crop residue in the state for grazing. After receiving a USDA Sustainable Agriculture Research and Education grant, the team started its project by sending out a survey to producers and consultants to determine why more residue isn't used.

NO IMPACT ON YIELDS: The results from the first two years of a University of Nebraska study have indicated no difference in subsequent yield between grazing, baling, or not grazing or baling crop residues at any of the cooperator sites.

Initially, the presumption was producers were concerned about grazing corn residue because of the impact on subsequent crop yields, soil components, and the water holding and retention capacity of the soil, according to Rick Rasby, University of Nebraska beef specialist. If all the corn residue in Nebraska was used, 10.3 million acres would be available for grazing. Rasby said each acre of irrigated land could produce an estimated 3.81 tons of feed, while dryland could produce 2.67 tons.

At less than $25 an acre, crop residue grazing is an economical choice for cattle producers. "When I came to the university 30 years ago, it was cheaper to summer a cow than winter one," Rasby told producers during the Nebraska Grazing Conference in Kearney. "Now, in many cases, it is cheaper to winter a cow than summer one, especially if you can incorporate cover crops and crop residue," he added.

Rasby said most crop residue at the western end of the state is already utilized because of the close proximity to cattle. "As you move farther east, less residue is grazed," he says. "What we wanted to know by doing this survey is why that is."

MORE COULD BE GRAZED: At the Nebraska Grazing Conference, Rick Rasby noted if all the corn residue in Nebraska was used, 10.3 million acres would be available for grazing. Irrigated land could produce an estimated 3.81 tons of feed per acre, while dryland could produce 2.67 tons per acre.

The survey found 82% of crop consultants recommend their producers graze crop residue; 52% of the producers responding to the survey said they graze crop residue. The majority of producers who didn't allow corn residue grazing felt it had a negative effect on their current farming practices, and caused damage to irrigation equipment and soil compaction. Others reasons were lack of water or fencing for livestock, lack of livestock, interference with fall work and not enough payment.

With these results in hand, Rasby and a team of researchers used this grant to set up six cooperator sites throughout the state. Study locations were Ainsworth, Norfolk, Odessa, Scottsbluff, Nebraska City and Clay Center. At each of these locations, cooperators agreed to three treatments over a three-year period: grazing, baling, and control (no grazing or baling). All sites were under no-till management and pivot-irrigated, except Odessa that was subsurface-irrigated, and Nebraska City was dryland.

The results from the first two years of this study have indicated no difference in yield between grazing, baling, or not grazing or baling crop residues at any of the cooperator sites, Rasby said. What the study did show was a significant loss of ground cover if the crop residue was baled. This is mostly because when cattle graze, they only eat the husk and leaves, leaving the lower nutrient cob and stalk behind.

"There was also no difference between years in crop yields," he said. "We have one more year of fall data collection left, but I really don't expect to see anything different."

"In the short term, grazing corn residue provides a potential feed resource, without negatively impacting future grain and stover yield, or the harvest index," he said. "Grazing can be compatible with modern farming practices, but stocking rate is critical."

Clark writes from Potter.