Time and timing - Hopkins sees benefits of grazing for weed controlWritten by Saige Albert
Rock Springs – “I think that frequently, it is the little things we do in paying attention to management that really make a difference,” said Bill Hopkins during the 2014 Wyoming Weed and Pest Conference.
Hopkins, a long-time manager at Deseret Ranches, said that proper time and timing is the most important part of management.
“What I’m really into is grazing management and ways to manage grazing so we don’t have quite as much risk of some of the noxious weeds,” he continued.
Hopkins was instrumental in developing the Grazing Improvement Program in the Utah Department of Agriculture, and he said that in developing the program, they organized a set of scientists and land managers to determine what is important as far as management is concerned.
“The key issue here is management,” Hopkins said.
The group came up with two main points.
“We suggested that healthy watersheds are the common denominator for clean, abundant water, diversity and abundance of wildlife and sustainable grazing opportunities for livestock,” he said, noting that the assertion was easy for many people to get behind. “We also suggested that well-managed livestock grazing is the most effective landscape tool to maintain and protect watershed health and wildlife values.”
Hopkins further noted that with over 45 million acres of grazing land in Utah, incremental improvements in grazing management yield big paybacks.
“We have done some economic studies through Utah State University and, even in counties that are sparsely populated and don’t have much business, every cow represented at least $1,000 in economic activity,” he said. “That is a big deal.”
The team of scientists also developed a short list of management principles that can help to improve grazing lands.
“The scientists said most rangeland isn’t overstocked, but grazing is often undermanaged,” Hopkins continued. “Grazing on public land in Utah has declined four-fold since 1960. Most of that is sheep, but cattle have also declined to some degree.”
The team continued that grazing impacts are managed by controlling the time – or how long animals are in a pasture or area, and timing – or the season of use.
“Those two things are our main focus as we work with grazing boards and specialists,” he said.
Frequency of grazing and intensity of grazing are also included, but if time and timing are managed, those factors are less important and take care of themselves.
Finally, the team emphasized monitoring to address impacts and ensure that management is achieving its goals.
On Deseret Ranches, Hopkins noted that a 20-pasture grazing rotation system is used for each bunch of cattle to facilitate changing the time and timing of grazing.
“The cattle have about 20 pastures to last them from the first of April to about Thanksgiving Day,” he said. “Their grazing periods are pretty short – only one to two weeks depending on pasture size.”
At the beginning of the year, the cattle graze last year’s forage because they are on pastures that were rested the previous year.
“The point is, we are changing the season of use,” Hopkins commented. “The idea is to graze the plants when they are in a different stage of growth.”
In their region, the critical growing period is from May 10 to June 20. With their rotation system, Hopkins noted that pastures are only grazed during the critical period once every five years or so.
“It really allows those most palatable plants to get four to five years of rest in a 10-year period,” he commented.
Reasons for grazing
In grazing in short periods and not grazing the same pastures at the same time each year, Hopkins said, “It decreases selectivity and increases diet breadth.”
Under long duration grazing, cattle are allowed to select the most palatable plants. At the same time, they put less pressure on less palatable plants.
“With time control, that is very different. It changes the way cattle graze,” he said. “When we open the gate on a pasture, the first plants they come to, they eat.”
“The cows change the way they view the world, and the eat everything from the first day they are in the pasture,” Hopkins continued. “It maintains and even increases diversity of plant forms. We put pressure on less palatable species.”
Opportunity for seed production, plant density and diversity increase, and bare ground is also decreased.
“If we can decrease bare ground, we have less risk for weeds, and we get more water in the ground,” Hopkins said.
By increasing the number of plants in pastures and on the ground, bare ground is decreased, providing less opportunity for weed growth.
“When we decrease bare ground, we get more water into the ground,” Hopkins noted. “Over time, things get better and better and better.”
Diversity of species increases production, and greater management flexibility is allowed.
As an example, Hopkins looked at musk thistle in one particular area at Desert Ranch.
“When I got to the ranch, we had a problem with musk thistle here,” said Hopkins. “Over time – a 28-year period – using time and timing in our grazing, we were able to dramatically decrease the musk thistle.”
Hopkins also noted that cattle now eat musk thistle using a timed grazing strategy, creating a near disappearance of the weed.
“The change was dramatic,” he said. “It took 25 years, but it is basically gone now.”
Hopkins said, “The bottom line is, the less bare ground we have, the less weeds we have. We need to manage grass so it can compete and cover the ground. The management is key.”