In the wild, herds of buffalo, elk, etc. cluster together to protect themselves from predators.
As the densely populated group moves around, it clears out vegetation and leaves manure, which their hooves mix into the ground.
This process produces fertile areas that become meadows and forests.
When predators are removed, this process stops.
Without predators, the herd animals spread out, they eat some of this and some of that, they leave manure here and there, and it doesn't get mixed into the soil.
The ground dries up, loses vegetation, and smaller wildlife leaves or dies out.
Wolves were removed from Yellowstone Park to protect the elk herds.
The elk stopped herding and spread out, and the result was an ecological disaster.
Science eventually discovered this process, and was able to reverse much of the damage, by reintroducing wolves to the park.
Similarly, simply removing the herd animals has the same bad effect, as when the buffalo were slaughtered to extinction, and the American prairies became the dust bowl.
An ideal farm would annually rotate several fields: one fallow, one with cattle, and the rest with crops that replenish the soil with nutrients suitable for next year's crop.
Even with the cattle, this arrangement can have a negative (good) carbon footprint, as carbon is incorporated into the soil rather than being released into the air.
These fields will have living soil, full of bacteria, worms, etc., not the sterile dirt now used by big agriculture, which is effectively hydroponic gardening with massive amounts of chemical fertilizer.
The modern plough also worsened the situation.
Traditional ploughs simply scratched a temporary channel into the soil into which seeds could be dropped, but now the soil is completely turned over, damaging its living components and making it easier to blow away.
Argentina's key resource, its agricultural soils, are being depleted by lack of crop rotation as soy farming encroaches on areas once used for corn, wheat and cattle grazing, according to local experts and a government source.
Soy takes more out of the soil than farmers can afford to put back by way of fertilizers. Only 37 percent is restored, meaning that 63 percent of each season's loss remains lost, according to government data.
"The soil is getting burned by the lack of organic material left behind by each corn crop," the government source said.
— Lack of Crop Rotation Slowly Turns Argentine Pampas into 'Sand' - Scientific American
Kiss the Ground, with Woody Harrelson, is an excellent film that describes how all this works in great detail.
The Kiss the Ground | Soil Health Solutions | Join the Movement! site provides much more information:
Cows grouped together every day are also farting and burping constantly. One of the byproducts of their digestive gas is also methane gas. But don’t blame the cow. There’s an important distinction between a cow on a CAFO [Concentrated Animal Farming Operation] and a grazing cow. When cows are eating a diet as they do in CAFOs – consisting of corn and soybeans, both of which cows are not designed to digest – their stomachs become upset. Cows have evolved to digest grasses, not modified corn. Instead of looking at their diet, the agriculture industry has masked the issue by giving them antibiotics, which damages their gut biome further and shows up in the meat we purchase. All of this activity is causing a lot of methane – whether it is the manure pits or the cows themselves.
If we switch over to a regenerative state where cows are out on open pasture and eating grasses they digest well, they aren’t burping and farting constantly. This is step one.
Most conventional grazing plots are now just left with annual plants because of this.
We’re talking decades of time – the perennials disappear (perhaps it was a perennial-dominated prairie), and as a result, the soil biology loses diversity, and farmers see sparser and sparser plant growth.
Eventually, this is called desertification, and you can’t raise cattle there at all.
What does regenerative cattle grazing look like? The earth has evolved with huge amounts of grazing animals and ruminants.
If we look at North America with its large herds of bison, those bison didn’t create the great desert, they created the great plains, some of the most fertile land in the world.
Africa has a similar history.
These are large examples that show having vast amounts of animals created richness, not the problems some worry about, like greenhouse gases.
Back in time, grazing animals were herded by predators.
As a form of safety, Bison or other large prey herds would group together and stay moving.
In turn, large herds never revisited a plot of land – they fertilized it until it was covered, then moved on (Animals don’t revisit where they’ve used the bathroom).
Crop rotation was the norm throughout much of the world for thousands of years.
It's only recently that better living through chemistry and efficient mono-culture mega-farms (necessary to support overpopulation) have changed the picture.
The nation of Israel for instance, codified good agricultural practices into its laws 3500 years ago:
And Native Americans practiced Three Sisters agriculture, in which corn (maize), beans, and squash were planted together:
… the fields were not tilled, enhancing soil fertility and the sustainability of the cropping system by limiting soil erosion and oxidation of soil organic matter.
The three crops benefit by being grown together.
The cornstalk serves as a trellis for the beans to climb, the beans fix nitrogen in the soil, and their twining vines stabilize the maize in high winds, and the wide leaves of the squash plant shade the ground, keeping the soil moist and helping prevent the establishment of weeds.
The prickly hairs of some squash varieties also deter pests, such as deer and raccoons.
Although this synergy had been traditionally reputed among American cultures, scientific confirmation has arrived only much more recently.