At least six out of 10 of your neighbors overgraze every pasture every year. That's the finding of a survey I conducted in 1999 by randomly selecting 500 commercial cattlemen and asking them to describe their grazing practices.
Of course, they didn't respond, “I overgraze.” In fact, most of your neighbors may not even know what overgrazing is or understand its consequences. But the data they provided shows that the majority of ranchers overgraze their lands routinely.
Overgrazing is grazing a plant before it has recovered from a previous grazing. When a plant is grazed severely, it uses energy stored in its roots to support regrowth.
As this energy is used, the roots die back. The degree to which the roots die back depends on the severity of grazing. This root dieback is not a bad thing. It adds organic matter to the soil, which increases soil porosity, the infiltration rate of water and the soil's moisture-holding capacity. After enough leaves have regrown, the roots will regrow as well.
A plant is overgrazed when it's re-grazed before the roots recover. Overgrazing can reduce root growth by 90%. Because there's less root growth, pastures are less productive.
Soils have less organic matter and become less fertile.
The infiltration rate and moisture-holding capacity drop.
Susceptibility to compaction increases.
Desirable plants become stressed, while weedier species thrive in these harsher conditions. Weeds don't make the land unhealthy. They appear because the land is unhealthy. Overgrazing is often the cause.
Move Livestock Before Regrowth Begins
I recently spoke to 120 ranchers in Reno, NV, about grazing management. When I asked them how to prevent overgrazing, they suggested reducing animal numbers. But that won't stop overgrazing.
Animals graze selectively. Given a chance, they will overgraze. The newest growth is the most palatable, nutritious forage in the pasture. Even one cow in a big pasture will overgraze plants if she's kept there long enough.
Overgrazing isn't a function of animal numbers. It's a function of time. Overgrazing happens when animals are kept in a paddock too long or brought back too soon.
To stop overgrazing, producers must move livestock out of a pasture before regrowth begins. During periods of fast growth, overgrazing will occur if livestock are kept in a paddock for more than three or four days.
Equally important, we need to make sure we don't bring the animals back before plants have recovered. Stan Parsons once told me that too short a rest period was the biggest problem in grazing management.
Overgrazing can be stopped with 8-10 paddocks. When growth is fast, recovery periods of four to six weeks may be adequate.
Eight to 10 paddocks will result in graze periods of about four days. When growth is slow, rest periods of 90 days or more may be needed.
If you have 10 paddocks and wanted 90 days of rest, animals would stay in each paddock for 10 days. Since growth is slow, that's okay because there probably isn't much regrowth after just 10 days.
You might conclude that eight to 10 paddocks gives a manager adequate control over grazing. If we only cared about the plants, you'd be right. But shorter graze periods will improve livestock performance, too. To shorten the graze period and provide for plant needs, 15-20 paddocks or more/herd are often needed.
That may seem like a lot of paddocks, but that all depends on your perspective. Many of our clients have more than 25 paddocks/herd.
One friend in New Zealand strip grazes each of his 160 paddocks in five strips, effectively making a total of 800 paddocks! He uses one- and two-wire, hi-tensile electric fences for the larger paddocks and builds daily “breaks” out of polywire. He has one of the most profitable grazing businesses I've ever seen.
Economic sustainability can't be achieved without environmental sustainability. The first step to achieving environmental sustainability is to stop overgrazing. That's essential when you're ranching for profit.