Planning for Adaptive Grazing Management

Chris Schachtschneider, OSU Umatilla & Morrow County Extension Agent chris.schacht@oregonstate.edu & Vanessa Schroeder, Faculty Research Assistant, OSU Extension Service Eastern Oregon Agricultural Research Center vanessa.schroeder@oregonstate.edu

Successful ranching operations employ a grazing management plan that balances forage use with maintaining or improving rangeland health. Effective grazing management plans can increase forage base and profitability with relatively low inputs. Producers have reported that grazing management has allowed them to focus on what they want to improve and create a plan to do so. Through this process, producers have demonstrated increased forage production and on one ranch, a producer achieved an increase of upwards of 485 percent over a five-year period. Factors to consider for successful land management when planning are 1) General rangeland ecology, the balance between timing and intensity, 2) the art and science of grazing management (i.e. adaptive management), and 3) tools to help you be successful.

Rangeland Ecology: A brief overview

Disturbances, such as wildfire, drought, flooding and grazing are common to rangelands. While our plant communities are adapted to some level of disturbance, as land stewards, our job is to manage the disturbances we have control of, such as cattle grazing, to maintain or improve ecological function. This can be achieved by managing the timing and intensity of livestock use to balance both under and overuse of forages. If you are interested in learning more of the details of rangeland ecology, Saving the Sagebrush Sea and The Ecological Provinces of Oregon are two great resources.

Timing

It is not necessary to know how to identify every species

on the range to develop an effective grazing management plan. Plants can be categorized into key groups based on the role they play in the ecosystem (Figure 1). As managers, we can then tailor our management practices to ensure these groups are in balance and functioning as a healthy ecosystem. Each of these groups have different growing characteristics which enable them to thrive within the ecosystem. An effective grazing management plan aims to increase desirable deep-rooted perennial grasses and to decrease invasive annual grasses and other noxious weeds. At various times of the year, certain groups will be desired, tolerated or avoided by livestock based on the growth stage of the plant and the nutrients it contains. For example, cheatgrass is highly palatable and desired by cattle in the early spring, but becomes tolerated or avoided after seed set, then palatable again after fall rains.

Grasses are most vulnerable during the stages leading up to reproduction (e.g. flowering and seed production) and are most susceptible to grazing when they are devoting their resources to production of seed heads. When cattle graze grass stalks that are forming seed heads, those stalks cannot continue to grow, but must re-start growth from resources stored in the plant’s base. After plants set seed, they become less vulnerable to grazing. Varying the timing of grazing each season, such as spring grazing one year and deferring grazing until after seed-set the next or allowing a full year of rest, can help beneficial plants thrive in the community. A successful example of this practice can be found in New Mexico and Nevada, where many of

ing the time when they graze

benefits if too many animals

their pastures. In theory, this are kept in one location too

will alter the timing enough

long; when grazing with

where individual plant species high stocking rates for short

are not always venerable during periods of time, it is critical

planned grazing. Granted, due to closely monitor pastures to

to the vast differences in our

prevent over-grazing. Finding

climate, their system may not fit all our pastures. A good grazing plan should allow enough time

Figure 1 Visual representation of various plant functional groups. The importance of each one will depend on the area in which a pasture is located and the needs of the ecosystem.

the balance is key and varies for each operation. Taking detailed notes on manage

between grazing to allow the grazed plant to fully recover before being grazed again. In the high desert of Eastern Oregon, grazing may only be beneficial once each year, but in the Willamette Valley, that recovery could happen in as short as 20 to 30 days.

Intensity

Consider a scenario with equivalent intensity (cow grazing days) in two pastures: in one pasture, ten cows graze season long for 90 days. In an adjacent, similarly sized pasture, 90 cows graze for ten days. Each pasture experienced 900 cow-graze days, but in pasture one, the same ten cows visit water daily throughout the season. Given these two scenarios, which disturbance do you think will leave a noticeable trail? Which one allows plants to regrow after they have been trampled or eaten? The intensity and timing in which we use pastures has a great effect. Since most grasses/forages have evolved with disturbances, such as grazing, one defoliation event each year will generally not harm the plant, unless it is severe enough to penetrate the base, killing the growth points. Just like the ten cows going to water once a day all season long, repeated disturbance without allowing for recovery can be detrimental. Generally, the first bite does not severely affect the plant, but when an animal continuously grazes a single plant, we begin to see negative implications for pasture health. Grazing pastures with a higher stocking rate for shorter amounts of time can help prevent cattle selecting a single species and re-grazing the same plants repeatedly, thereby improving pasture utilization. Range riding and selective placement of supplement and water can improve cattle distribution in pastures with lower stocking rates.

The intensity of use is not limited to the amount of vegetation removed from grazing, but includes all livestock activities, such as traveling and laying down, and should be considered in both scenarios. Steve Cote discussed the “herd effect” in his newest book, Manual of Stockmanship, and has anecdotal evidence of concentrated herds having secondary positive benefits of vegetation the following year. Grazing intensity also interacts strongly with the season of use: grazing a pasture heavily in the spring when grasses are actively allocating resources to seed development will have a more detrimental effect than that same pasture

ment actions and pasture condition the following season will help determine the balance for your operation.

Balancing use and rest

A grazing management plan can aid in addressing the balance between use and rest to achieve targeted goals. Typically, within each pasture there will be over- and under-utilized vegetation. Generally, areas around water will be over-utilized because cattle frequently graze the vegetation to and from water, or camp in the lush shade. Distant or remote portions of a pasture are often underutilized. Ideally, managers can plan and implement grazing to a level where cattle utilize vegetation to achieve weight gains, while simultaneously allowing the vegetation to grow fuller or stronger in preparation for the next disturbance. Management intensive grazing was developed for smaller acreage where electric fencing is used to concentrate cattle for short durations, then be quickly moved to another small paddock. At other scales, this may not be feasible, but changing the use of pastures within a season may. This can alter the timing of use to change the targeted plant communities by livestock and allow others to complete their growth cycle that year. During the growing season is typically when plants are most vulnerable and minimizing that impact can be beneficial. The Birdwell & Clark Ranch in Texas has minimized grazing during the growing season to two and a half days in any one pasture each year, enabling their vegetation to recover while resources are still available. You can watch their experience in a short film titled, “Herd Impact” at www.carboncowboys.org.

Adequate “rest” for a plant is the amount of time needed to fully recover from the previous disturbance. On irrigated pasture, this could be a couple weeks and in the desert a year or more and varies depending on the disturbance intensity. This rest requirement will vary even within a pasture from the upland to riparian areas. Identifying

Frequency of use

+1-less than 2 uses

0-2 uses Intensity of use

+1-Light use

0-Moderate use Opportunity for rest

-2-No rest

0-Some rest

that balance can be challenging and may require several attempts with subsequent tweaking to find the ideal amount.

Art and Science of Grazing Management

Just like in most things in life, there are certain principals and concepts that can be taught, but to truly understand and be good at anything, perfecting the art is a must. Wade Black, nationally renowned horse trainer and instructor at Treasure Valley Community College in Ontario, teaches his students the need for the art and the science in horsemanship. In the classroom, they discuss animal behavior, training tips and tactics and fundamentals of horsemanship. But knowing and properly implementing are two different things. Students need hands-on experience to conceptualize and fine tune timing and intensity of their training to become effective. We too will need to learn the art of grazing management. The tools described are great references to see if the current management is heading in the right direction, but there is also power in the art of being able to look at a pasture and “feel” the cow head days needed or stocking density required to achieve the goal. Mistakes are inevitable and should be learning opportunities rather than failures. As we practice grazing management and thoroughly document our decisions and the subsequent outcomes, we will become more proficient at the art where the “mistakes” become less severe and our success compounded.

Tools available for grazing planning

Oregon State University is dedicated to facilitating the development of a grazing plan. Some metrics are required to assess what is needed on an individual pasture or ranch and will help you determine when your changes in grazing management are becoming effective. Many extension offices have rangeland monitoring kits available to borrow as well as training to utilize them. Please contact your local extension office for more information regarding these kits.

Google Earth Pro provides a platform for land managers to visually and spatially document and track through time planning and implementation of your grazing plan. Using this tool, managers can visually assess a proposed plan for feasibility, document the flow of cattle movement across the landscape and track the effectiveness of changes in grazing management through time and space. OSU currently has a hybrid course available to help producers navigate this new technology.

Our rangeland state specialist, Dustin Johnson, and his team have created a “60 mph” monitoring assessment tool to watch and document trends. The Threat Based Land Management State and Transition Models provide a basic understanding of the current threats, such as annual grasses and juniper encroachment and assessment tools to identify if the trend is heading in the desired direction.

The Web Soil Survey from the National Resource Conservation Service is a great tool to identify soil types and production estimates for planning purposes. This can be incorporated into Google Earth Pro as another layer for monitoring and planning purposes. Your local NRCS or Extension office can assist you in navigating this program.

Finally, a tool used extensively in other systems, but relatively unknown in Oregon rangelands, is the Grazing Resource Index (GRI). The GRI reduces the pasture monitoring into three categories: Frequency – How many times an individual pant can be defoliated during the grazing period, Intensity – How much leaf material is removed during the grazing period and Opportunity ¬– Time the pasture has to recover from the grazing event. Categories are assigned a numerical value from -2 to 2, then are added up for the total GRI (Figure 2). So, let’s say a grazing plan consisted of moving livestock once a day with high forage use and not returning to that area for a year. This scenario would receive a total GRI score of +2 (Frequency = +1, Intensity = -1, Opportunity = +2). This tool can be used to identify which areas of the plan are working and which can be improved. Maybe increasing number of pastures can improve both frequency and opportunity scores? Altering stocking density could affect any of these categories as well. For more information visit the website listed in the references.

Putting it all together

An effective grazing management plan can improve rangeland health and an operation’s bottom line. However, managing grazing in an ecosystem as variable as the sagebrush steppe, is far from simple and requires a balance between the art and the science. An adaptive grazing management plan comprised of careful planning, documentation and evaluation of management actions, followed by staying the course or tweaking and improving management, marries the art to the science of rangeland management. OSU provides a variety of tools to create and improve grazing management plans. So while you are waiting for that grass to green up to turn cows out this year, think a little about your current grazing plan (or routine) and see if there are things you could do to improve or new tools you can learn. Reach out to your extension agent or access the mentioned tools online. Continual improvement can be instrumental to long term sustainability. •