Research Explores Effects of Long-Term Residue Grazing

Fall grazing in this study did not negatively affect any of the soil-structure characteristics relative to controls.
Fall grazing in this study did not negatively affect any of the soil-structure characteristics relative to controls.
(John Maday)

Post-harvest corn residue provides ground cover and organic material, and also carries value as a low-cost feed source for cattle during the fall through spring. Several studies have shown little to no negative impact of grazing, at typical stocking rates, on subsequent crop yields. Less is known though, about the long-term effects of grazing on soil compaction, structural quality, organic-matter content or nutrient cycling.

Earlier this week, we posted an article titled “Does residue grazing affect later crop yields?” This follow-up, also based on research from the University of Nebraska, looks at the longer-term effects of residue grazing on soil properties.

Nebraska researchers recently reported on a 16-year study, evaluating the effects of grazing on no-till, irrigated land in a corn-soybean rotation in eastern Nebraska. Their report, titled Effect of Long-Term Corn Residue Grazing on Soil Properties,” is published in the 2017 Nebraska Research Report.

The researchers compared three management systems:

  • Fall grazing from November through January, with cattle stocked at 1.8 to 2.5 animal unit months (AUM) per acre.
  • Spring grazing from February through mid-April, with cattle stocked at 2.3 to 3.1 AUM per acre.
  • Control fields with no grazing.

In addition to yields, the researchers recorded soil cone index and bulk density as measures of compaction, soil organic matter, nutrients and wet aggregate stability.

Fall grazing in this study did not negatively affect any of the soil-structure characteristics relative to controls. Subsequent corn and soybean yields increased following fall grazing. The researchers note they designed the spring grazing program in this study to determine whether heavy stocking rates after the soil thawed would affect soil characteristics. They found that soil cone index increased somewhat following spring grazing, but remained below threshold levels where root growth could be restricted. Soil bulk density and wet aggregate stability were unaffected relative to controls. Soybean yields increased while corn yields were unaffected.

Spring or fall grazing had no significant effect on soil organic matter, although the researchers recorded a small numeric increase for both grazing systems compared with control plots.  The researchers note that grazing at normal stocking rates typically removes less than 25% of the crop residue, and cattle manure helps return significant volumes of organic material to the soil, especially if considering the additional manure nutrients resulting from supplemental feeds typically provided to cattle grazing corn residue. Also, the hoof action from grazing cattle could help incorporate residue into the soil, preventing photo-oxidation and thus benefitting soil organic material.

The researchers conclude that, under the conditions of this study, long-term corn-stubble grazing does not negatively affect soil structure, organic matter content or subsequent crop yields.

To help landowners determine appropriate stocking rates and grazing intervals on harvested corn fields, the University of Nebraska offers a Corn Stalk Grazing Calculator online.

For more on grazing corn residue, see these articles on BovineVetOnline:

Test Cornstalks for Nitrates before Feeding

Comparing Winter Management Systems

Three Tips for Winter Feeding Beef Cattle

 

Latest News

Skills Survey Reveals U.S. Agriculture & Food Industry Workforce Needs and Gaps
Skills Survey Reveals U.S. Agriculture & Food Industry Workforce Needs and Gaps

U.S. employers report challenges in finding suitable job candidates with work-ready skills to fill open roles in ag. The AgCareers.com U.S. Skills Survey offers insights, data and trends to address skill development.

USDA Authorizes CRP Graze and Hay Donations to Wildfire Victims
USDA Authorizes CRP Graze and Hay Donations to Wildfire Victims

Conservation Reserve Program (CRP) participants can donate emergency grazing authority to ranchers in Nebraska, Oklahoma and Texas impacted by recent wildfires.

New Guide Helps Producers Maximize Values of Cull Cows
New Guide Helps Producers Maximize Values of Cull Cows

A new resource developed by the National Cattlemen’s Beef Association and CattleFax helps cattle producers maximize profitability from their culling decisions.

How Ranchers can Feel More Energized and Reduce their Aches and Pains
How Ranchers can Feel More Energized and Reduce their Aches and Pains

We can’t care for our livestock, resources and families without caring for ourselves first. That seems even harder during the busy seasons, but it isn’t impossible and even one thing a day makes a difference.

Profit Tracker: Packer/Feeder Margin Spread Grows
Profit Tracker: Packer/Feeder Margin Spread Grows

Last week’s rally to new record prices pushed packer and feeder margins in opposite directions. Pork producer margins continue higher with prices now above year ago.

Spring Forward Horse Health with Vaccinations
Spring Forward Horse Health with Vaccinations

As horses are exposed to the environment, wildlife and mosquitoes that transmit the five core equine diseases, it’s important to follow the core equine disease vaccination protocol.