Posted: Thursday, January 05, 2012 10:00 AM
By DOUG WARNOCK
For the Capital Press
Successful management of rangelands in the 21st century means working with nature, according to Jim Gerrish, a nationally known grazing management educator and consultant who spoke at the recent Quivira Coalition Conference.
Gerrish is a former University of Missouri research scientist now living in Idaho, where he manages a ranch and operates a consulting business. The conference was in Albuquerque, N.M.
Planned grazing management is a way of working with nature and not against it. Working with nature means looking after the ecosystem processes, which are solar energy, water, soil minerals and biodiversity. Improved ecosystem health and higher productivity are the results. Production is often increased as much as 70 percent without fertilization or seeding, just by managing better, Gerrish said.
"An acre of land is a 43,560-square-foot solar panel that converts sunlight into plant tissue. How good is your solar panel?" Gerrish asked. The solar panel is most efficient when the soil surface is covered with healthy, vigorous plant life. Having bare soil wastes solar energy. A soil surface covered by healthy plants does the best job of catching and retaining precipitation.
He stated that 90 percent of what goes into a grazing animal comes out the back and is a valuable source of soil minerals. Biodiversity is important in that a mixed plant community captures more sunlight, provides a longer and more stable growing season and offers a more diverse and nutritional diet for animals.
Gerrish challenged graziers to build a better solar panel by reducing bare soil and grazing in the second phase of plant growth as much as possible.
There are three main growth phases for grass plants. The first is the smaller, fast-growing phase where plants are the most vulnerable to grazing.
The second is still somewhat rapid in growth, but plants are larger, stronger and more able to sustain reasonable tissue loss from grazing. Phase two plants provide the best quantity of nutritious forage.
Phase three is the stage of maturity where plants have the least palatability, less nutritional value and are coarser by nature.
He stressed that plants grazed too close will take longer to recover.
Biodiversity can be increased by leaving enough residual plant tissue, varying the season of use, interseeding when appropriate and allowing adequate recovery time.
"Good grazing management is more about time rather than about the number of animals," Gerrish said. "Too much time on a pasture is the reason for negative results from grazing. Allowing ample recovery time is the key to success."
"Stock density is a powerful tool in grazing management," Gerrish said. Stock density is the number of animals or total animal weight assigned to a specific area at a specific time. The most successful management is from having more animals on an area for a short time and moving them before they remove an excessive amount of plant tissue.
The keys to grazing success, Gerrish said, are maintaining a diverse vegetative cover on the soil, balancing use and recovery, avoiding animal concentration points and grazing as much as possible in the phase two growth stage.
Doug Warnock, retired from Washington State University Extension, now lives on a ranch in the Touchet River Valley where he consults and writes on ranch management.