Midwest will be a land of dry and harvested corn fields by late fall, presenting beautiful scenery. It seems lovely on highway drives. But the leftovers of corn are of no use for inexperienced ones.
But these corn residues are valuable for those who know their worth. For instance, grazing cattle can use their cobs, kernels, husks and scattered leaves as food. So, if you manage these residues well, you can use them as cost-effective feed, increasing the farm’s revenue. Moreover, you can also use the land to feed people.
A member of the American Society of Agronomy, Morgan Grabau, studied the interaction between crop productivity and cattle grazing. She presented her research at a recent virtual 2020 ASA-CSSA-SSSA Annual Meeting. American Society of Agronomy, the Soil Science Society of America, and the Crop Science Society of America hosted this meeting.
According to Grabau, only 15% of the corn litter is used for cattle grazing in the central U.S. It is the most neglected resource that demands attention.
Farmers have another concern of soil compaction, which may happen due to cattle grazing. Too much soil compaction leads to poor crop yield in the next season. That’s why the main focus of Grabau’s work was to find a solution for soil compaction.
Previous research by Grabau’s team indicates that winter and fall grazing doesn’t cause too much compaction. This is because the dry and frozen soil doesn’t allow the cattle hooves to stamp.
However, the current research of Grabau focuses on the effects of cattle grazing in spring when soil is wet.
In the current research, Grabau studied two different grazing systems. First, researchers allowed cattle to graze corn fields for 45 days. The time for this study started in mid-February.
The number of cattle tripled in the second system. However, the grazing time was reduced to 15 days. This study started in March. In this, the total amount of grazing in both systems was equal.
The only difference was the time that cattle spent on wet fields. This difference in time decides how the soil will respond to trampling.
The researchers chose the corn fields in Nebraska to conduct their research. Half of the corn fields in their chosen field are grazed after harvest. First, the research team various soil properties that may lead to soil compaction. Secondly, they measure the yield of soybeans grown in the grazed fields the following season.
They didn’t rely on one-time experiments. Instead, they repeat the experiment for two years to get more precise results.
“Much like previous fall grazing studies, minimal effects were seen on soil properties and yield due to spring grazing, regardless of the number of cattle and area grazed,” says Grabau.
The research findings indicated some changes in soybean productivity after cattle grazing. However, the grazing in the second system causes an increase in the crop yield.
Grabau explains this increase in yield with the removal of residue and high soil temperature. Both these conditions are suitable for plant growth. However, the research team also observed some soil compaction. But it was not so deep and was limited only to the field surface.
According to Grabau, compaction is temporary, and the soil becomes normal with time due to continuous saturation. Moreover, compaction also becomes minimum due to microbial activity.
To sum up, soybean seedlings grow effectively after cattle grazing. Even soil compaction on the surface level doesn’t affect the yield much.
Grabau’s team observed minimum compaction even when the fields were wet in the spring. As a result, there was a minimum adverse effect on the soybean yields.
No doubt, winter and fall grazing best. But, Grabau suggests farmers accept spring grazing.
“The integration of crops and livestock is a beneficial production system,” says Grabau. “Grazing cattle on corn residue can be a great way to make even more food for human consumption from corn fields, as both the corn grain and plant residue can be used as feed for livestock.”
Who supported the research?
Since Morgan Grabau is a graduate student in animal science at the University of Nebraska-Lincoln, Nebraska Agricultural Experiment Station supported this research. Moreover, the Hatch Multistate Research Program of the United States Department of Agriculture National Institute of Food and Agriculture also provided funds for this research.