Managing pasture resources for health and productivity improves profitability
Powell – The process of evaluating pastures involves both pasture health and pasture productivity, and Jim Gerrish of the American Lands Grazing Association admits that most pastures around the country only produce a maximum of half of their potential.
“When we look at irrigated pasture, we are looking at traits that determine the long-term productivity of the land,” says Gerrish. “Most farmers and ranchers don’t have a real grasp on the condition and quality of their pastures.”
The National Grazing Association offers a multi-page guide to assessing pasture conditions, but Gerrish notes that its complexity makes it difficult to understand, and he has developed a tool to make assessing pastures much easier.
“No one does pasture monitoring because the tool is complex,” Gerrish says, also commenting that irrigated pasture is very different from rangeland, largely because of water availability, and should be monitored accordingly.
“There are two things that come into play when evaluating pastures. One is pasture health and long-term productivity,” says Gerrish. “We are looking at the traits that determine the long term productivity and also looking at the output of the pasture.”
A number of factors affect pasture productivity, and Gerrish marks stand density as a very important aspect of how much forage will be available.
He asks, “How much of the ground is covered by green living plant material?”
“We typically look at stand density in terms of percent ground cover, which is different from the basal cover used in range monitoring,” he explains. “We are looking more at canopy cover and the photosynthetic capacity in pasture assessments.”
The more canopy cover a pasture has, the more effectively it will be able to capture solar energy, and the ability to capture solar energy is also affected by how big or tall plants are allowed to get.
“Forage will thin out as it gets bigger and taller,” elaborates Gerrish. “To have really productive pastures, they need to be thick and dense. More stock days per acre can be harvested in a thick pasture than a thin one.”
To emphasize the importance of ground cover, Gerrish also says, “When you have sunlight hitting the dirt, that is a pound of beef you don’t have to sell.”
Diversity in species
The composition of a pasture affects productivity as well, and Gerrish says, “The greater diversity in species and functional group diversity, the more likely pasture will have something green and growing more days of the year.”
Diversity in a pasture will also increase solar energy capture and decrease the need for mineral supplementation.
“From an animal well-being and maintenance standpoint, we can also see a positive effect from the cyto-chemicals that bolster the immune system with a diverse pasture,” adds Gerrish.
Desired plant composition is also variable, depending on the operation.
“Ranchers must understand their animals and environment enough to know what is desirable to accomplish their goals,” he explains. “A sheep producer doesn’t want the same species a dairy farmer would.”
To assess the composition of pastures, Gerrish suggests the human eye is one of the most accurate tools to use. He also emphasizes the importance of walking pastures and looking straight down at the forage, rather than across, to get accurate results.
Things that count
When visually monitoring pastures, assessing the health of the pasture also includes looking at vigor, health and robustness of the plant species. Gerrish notes that the amount of bare ground and litter present is also important.
“When sunlight hits bare ground, that is lost productivity,” says Gerrish. “We prefer to have litter on the surface. That is a very important part of the pasture ecosystem.”
Surface litter, including dead plants, leaves and other debris, is an important part of the water and mineral cycle. Litter is also preferable to bare ground because it helps to prevent against weed growth.
“Too much litter is also possible,” Gerrish adds, noting that excess litter can also stunt desirable plant growth.
Gerrish also looked at the utilization of pastures by animals as an assessment of pasture health, including severity and uniformity of use. Though severity of use may seem straight forward, and producers want to avoid over-grazing, Gerrish notes that under-stocking could be detrimental, as well.
“Under-stocking on a pasture can lead to changes in the composition,” he explains. “Pastures will lose legumes faster by underusing them than by overusing them.”
Overusing pastures will also remove desirable species and create less productive, usable pastures.
Uniform usage can be assessed by looking at preferred grazing areas and can also be managed. Changing the distance between water sources, for example, can encourage animals to utilize pasture more uniformly.
In assessing a pasture’s overall health and productivity, and managing to make improvements, Gerrish says pastures will support more animals over a longer timeframe
“The most difficult one is the very first time you monitor, because that means you actually have to take the step and do it,” he adds. “The people who do this on a regular basis have made it a very important part of their grazing program.”
Jim Gerrish spoke at Northwest College’s Spring Roundup in early 2012. Saige Albert is editor of the Wyoming Livestock Roundup and can be reached at email@example.com.
When, where and how?
Pastures can be effectively managed to produce more, according to Jim Gerrish of the American Lands Grazing Association, but to determine where a pasture stands, producers must use monitoring as a management technique.
Gerrish recommends a worksheet he developed to address 10 factors he identified as most important for pasture health. Those traits include diversity, desirability of species, composition, vigor, stand density, percentage of legumes, severity of use, uniformity of use, litter and soil resources.
“Monitoring tells me what my management needs to focus on,” says Gerrish. “It can help suggest what I need to do to improve.”
Gerrish adds that comparing data from year to year will help producers determine when improvements occur. Regular, consistent monitoring is essential to make comparisons, he says.
“We monitor once a year, but when you first start, you might want to monitor once in the spring and again in the early fall,” he explains. “It helps to see how pastures change over time.”