Create herd effect with adaptive grazing
Aljoe is the director of producer relations, and Smith is a wildlife and fisheries consultant, at the Noble Research Institute, Ardmore, Okla.
In the third and final installment of this series about getting started with regenerative grazing, we’ll address the keys to adaptive grazing, the selective use of high stock density grazing, and creating the desired herd effect.
As we’ve discussed, regenerative grazing is the primary management tool or set of practices in regenerative ranching. Guided by ecological principles, these practices use the benefits of grazing livestock to rebuild soil health and may also help diversify the enterprises and income a farm or ranch produces. The practice of adaptive grazing management is also called adaptive multi-paddock, or AMP, grazing, but we will refer to it as simply adaptive grazing.
There are four variables to manage in grazing: timing, frequency, intensity, and duration. When managed intentionally and adaptively, these four variables, plus the tool of stock density, can play a significant role in improving ecosystem function and soil health. So can the strategic use of herd effect, which is also called animal impact. This is the beneficial result of a concentrated and excited herd using its hooves to knock down old, standing vegetation and/or break up the soil.
Work your grazing plan
Once you and your animals are accustomed to the frequent grazing moves you’ve practiced on a small scale and you’ve had time to add more temporary fences and additional water sources, if needed, it’s time to implement the regenerative (adaptive) grazing management plan we discussed in the March issue of Hay & Forage Grower.
Your plan will have considered your regenerative goals, which may include some or all of the following: improving soil health and animal health, enhancing plant diversity, reducing brush encroachment, improving livestock production, and boosting profitability. Take time to adjust your grazing plan based on what you learned when you tried rotational grazing on a small scale, but also account for current forage growing conditions.
As you plot out and use your grazing charts based on your priority goals, remember the keys to adaptive grazing:
– Allow for long recovery periods, which is the most important variable to manage regardless of grazing approach. Recovery periods are adapted to growing conditions — longer recovery with slow growing conditions, and shorter recovery with rapid regrowing conditions.
– Keep grazing periods short, ideally no longer than three to four days in one area. It’s best to have the capability to move cattle daily — but be flexible. Extending grazing periods by a day or two as plant regrowth slows with reduced moisture conditions is acceptable. The key is to rotate cattle out of a pasture before they begin to regraze a grazed plant.
– Manage the grazing intensity, or the amount of forage grazed or defoliated versus the amount left untouched in a pasture. Typically, the rule of thumb is “take half, leave half,” which means graze the top half of the plant leaf material.
– Use high stock densities. Most producers who have implemented the first three keys of adaptive grazing are also using high stock densities. More often than not, you’ll need to increase the pounds of live-weight per acre to implement the first three keys to successful adaptive grazing. When using high stock densities, a manager needs to vary the stock densities, adapting to growing conditions and the amount of biomass accumulated prior to grazing. We do not want to become prescriptive or routinely use the same stock density for a paddock or pasture with every grazing event.
Capitalize on herd effect
Occasionally, one might want to use ultra-high stock density grazing (UHSD) in a pasture for short periods of time. Ultra-high stock density is the intentional increase in stock density achieved by providing a much smaller grazing paddock for a short time period (usually requiring multiple moves per day) to increase a desired herd effect on an area and/or reduce animal selectivity of grazeable forage.
Some ideal situations for UHSD are at peak forage production in the spring or early summer; during the transitions between cool-season and warm-season forage production (and vice versa); with introduced pastures and foraged cropland; and when there is an abundance of mature, less desirable (often dormant) plant material in a pasture. Especially in the last instance, be sure not to ignore livestock gut fill, physiological condition, and nutrient requirements when using UHSD. You may need to supplement the diet or provide more palatable forage for part of the day to avoid stressing the animals and jeopardizing production.
You also can make strategic applications of UHSD for very short time periods by placing mineral feeders, hay, and supplement at targeted sites, such as into woody thickets or briar patches. The animal impact at that density can remove much of the
undesired plant structure, and it feeds the soil biology through the trampling action. Herd effect can also disturb exposed, compacted soil surfaces, stimulating new plant recruitment and production during favorable moisture conditions.
Use a safe-to-learn approach
One word of caution when implementing UHSD: Use a “safe-to-learn” approach when learning how to apply it successfully. Begin with a situation where small setbacks during the learning process will not adversely affect you, the animals, or your operation. The safe-to-learn approach includes elements of how, where, and when.
Use existing resources with a few electric fence supplies and apply your best grazing management while adhering to the soil health principles. Select a location that is easy to manage and where you can take the time to thoroughly observe all grazing activities and soil and plant responses — near the headquarters, for example.
Start where you have a lot of forage and a definitive plan to guide your grazing process as you try higher stock densities. The plan includes estimates of forage production and the livestock’s daily grazing demand, duration of time the targeted area will last, the stock densities you want to try, and a contingency plan if things don’t go as intended.
Early successes can be built into future grazing plans, but it is the observations of the results later in the growing season that will guide you in your next applications of UHSD.
Keep tabs as you go
Monitor your grazing management activities throughout your regenerative ranching journey.
• Benchmark your soil health with soil tests (preferably a Haney Test) on your primary pastures.
• Use grazing charts to plan and monitor grazing activities and recovery.
• Create a diversity list to capture all the species of plants and animals you can locate on your ranch, and continually add to the list as the diversity grows.
• Take photos of key management areas and track changes over time.
• Use grazing “exclosures” (small, ungrazed areas) to measure ungrazed forage production at end of the growing seasons, moving exclosures to new locations every year or two.
• Every few years, use additional soil tests to analyze for improving soil health metrics.
Soil health, grazing, and sustainability can be integrally related. If continual improvement is the objective of a land manager — and it is for most — then understanding how to manage for improvements in soil health using adaptive grazing can lead to the long-term improvements for the soil, land stewardship, forage production, the ecosystem, and ranch economics. It is the culmination of these improvements that lead to true operational sustainability for generations to come.
AMP grazing boosts soil carbon, nitrogen
New research looking at adaptive multi-paddock, or AMP, grazing is documenting how the practice can help with climate change by capturing carbon and retaining nitrogen in the soil.
In 2018, a large-scale on-farm study in the southeastern United States compared AMP and conventional grazing grasslands across the fence from each other, looking at the effect of AMP grazing on soil carbon capture. The AMP sites averaged 13% more soil carbon and 9% more soil nitrogen down to a 1-meter depth than the conventional sites. In their 2021 Journal of Environmental Management article, the study authors concluded: “These findings provide evidence that AMP grazing is a management strategy to sequester carbon in the soil and retain nitrogen in the system, thus contributing to climate change mitigation.”
This article appeared in the August/September 2022 issue of Hay & Forage Grower on pages 20-21.
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