Row-crop yields won’t be hampered in fields that have been fall or winter grazed for cornstalks for 30-45 days to cut feed costs, says Nathan Mueller, South Dakota State University Extension agronomist.
Cattle consume only 20% of residue while grazing, according to SDSU research, which means there’s enough cover to keep soil erosion down in no-till and reduced-till systems.
“Grazing does not appear to be a real problem across an entire field,” assuming average stocking rates of 1.5 animal unit months. But there’s a perceived negative effect on corn yields – that grazing crop residue leads to soil compaction and nutrient removal, he says.
“A 15-year study at the University of Nebraska has shown that fall grazing of cornstalks does not decrease yield in the following soybean or corn crop. Likewise, no-till research at Iowa State University found no significant difference in soybean yields between grazed and ungrazed cornstalks,” Mueller says (see table below).
Bulk density, a compaction measurement taken at the Iowa State study, showed no difference between grazed and ungrazed plots. But a measurement called penetration resistance was higher at the Chariton site with grazing.
“It is likely that concentrated traffic near water and mineral sources is expected to have some negative effect on soil physical properties and yield,” he says. “However, across an entire field, research shows yield of the following crop is not reduced by grazing cornstalks in the fall-winter months.”
To learn more, visit www.iGrow.org.