In Nebraska, it's an oft-cited fact that cattle outnumber people by nearly 4 to 1. West of the 100th Meridian, that much is obvious. But on the glacial-till soils of eastern Nebraska, cattle are far sparser. Many attribute the lack of bovines in the western Corn Belt to a lack of perennial pasture. With the right setup in place, however, crop residues and annual forages provide an opportunity to bring cattle back to the land.
In the last Resilient Ag Landscapes column, we covered opportunities for bringing cattle back to the land, but what soil health benefits do cattle provide when grazing cover crops?
Because cover crops are a fairly new area of research, the challenge is the lack of hard data to quantify these benefits. However, as Paul Jasa, University of Nebraska Extension engineer notes, there is plenty of anecdotal evidence from avid no-tillers and cover crop users.
"There are some people that swear you need livestock on the land," Jasa says. On the other hand, some landowners fear grazing cattle on their land will cause soil compaction. But cattle can benefit a cover crop system just as much as cover crops can benefit cattle. As Jasa notes, "when you have a living root system with cover crops, compaction isn't near as much of a concern."
One benefit, although not necessarily proven, is that the bacteria in the rumen are similar to the bacteria in the soil, and that grazing cattle helps improve the soil bacteria population.
Another benefit is that livestock trample covers into the soil, putting residue in contact with the soil and soil microbes, giving them a chance to cycle that residue much faster.
While cattle don't actually increase the nutrient content in the field, Jasa notes they do cycle it faster through the system by grazing biomass and leaving it on the field in the form of manure.
In addition, cattle do provide some alternative methods for establishing covers, like broadcast seeding a cocktail from a UTV, and letting the cattle incorporate the seed by tromping it in. "People worry about getting a good stand when broadcasting cover crops. But with a diverse cocktail mix, it works fairly well," Jasa says. "On a broadcast cocktail, you're going to have different plants fill in fairly well."
Mary Drewnoski, Extension beef systems specialist, notes there are some things to consider when growing cover crops for grazing. "Now, we need yield. Yield is king when it comes to cover crops for forage production," she says. "You can have both: soil health and grazing benefits. But you have to think about management based on your targeted goals, and go from there about how you manage."
With that in mind, the species grown will probably be a predominant grass mix, because grasses will typically outyield any other species. It also means seeding rates will need to be at least 30% higher than what is recommended for a cover crop grown solely for soil health purposes.
This also means managing the cover crop more like a cash crop, and may include irrigating in certain situations, or even fertilizing, depending on the previous crop, how much residual nitrogen is left over, and how much of a growing window there is for the cover crop.
Jasa notes when grazing annuals, it might be worth reconsidering the "take half, leave half" concept of rotational grazing. "There are some people that graze grass 6 inches tall, and if you take half off, 6 inches wasn't enough to cover the soil anyway," Jasa says. "If it's 2 feet high, it's no problem. We've got people with rye that's 6 feet tall. They can graze not just 3 feet, but 5 feet. The 'take half, leave half' has been modified now to leave enough or adequate soil protection."
"We know a lot of the organic matter benefits come from the roots, so grazing that top growth is OK as long as we keep enough cover on the ground," Drewnoski adds. "From the soil health standpoint, we're going to get actively growing roots, organic matter benefits, and if we make sure we don't take off too much biomass, we can still get erosion control benefits and even weed control."
The other key considerations are water and fencing. In Nebraska, supplying water to tanks on pivot-irrigated ground might be as simple as dropping a submersible pump in your well. Hauling water is another option, although not the most efficient. Of course, on these crop acres, permanent fencing likely isn't in place, but high-tensile wire is an inexpensive, yet effective means for temporary fencing.
Of course, if you don't have cattle, the first step is finding someone with cattle who's looking for a forage resource. This is where the next generation can come in. "The other opportunity is it's a way to bring young people back into the industry," Drewnoski says. "If you have a son or a daughter and they're looking at how they can come back to the farm, adding this enterprise might be a way to do it. It's another income stream, and they can be responsible for making those things work."
If you're lucky, collaborating with a cattle owner may mean a few steaks in the freezer.