Two things to avoid in grazing management are overstocking and overgrazing.
Texas range scientist Richard Teague says some people mistakenly confuse the two.
1. To avoid overstocking, make sure you don’t have too many animals so that you leave enough grass to feed them and perform ecosystem functions like shading the soil.
2. You also must avoid overgrazing, which occurs when you graze plants too long and don’t provide enough recovery time.
But the confusion doesn't end there. Many people believe by having just a few animals on the landscape you can achieve both goals, but those few animals generally return to the same plants again and again, eliminating recovery time and causing overgrazing.
Also, if allowed to graze where they want, animals tend to stay fairly close to a water source, until it’s grazed out and they have to move farther away. Also, they tend to graze their favorite plants again and again, often to the point of weakening and/or killing them, leaving the less valuable plants to thrive. These behaviors create a mix of undergrazing and stale plants and soil in the same pastures with overgrazed plants.
The heavily-grazed plants then have shallower roots, produce less biomass and are more adversely affected during dry years. The bare soil around them gets too hot and soil life becomes low-functioning or dies.
“Even under low stocking rates, if livestock are continuously grazing the same area they diminish and degrade certain patches of vegetation. Eventually those degraded patches increase in size, particularly during drought. Eventually the whole landscape is degraded. And if you have too many animals there all the time (overstocking) it speeds up that process,” Teague explains.
With heavy continuous grazing (overstocking and overgrazing), the landscape is dominated by less-productive short grasses and forbs. Light continuous grazing (which is overgrazing even though stocking rate is low) creates a lower proportion of tallgrass and quality forb species. With well-managed AMP grazing, plants have more recovery time and vegetation becomes predominately taller, more productive grasses.
For more on the development of grazing management read this article.