11/14/2024
Check out the article in the Oct. 2024 Rangelands Partnership newsletter Dr. Tolleson wrote!
Titled: “What? Not another grazing system study…”
“Yes, sort of. Let me explain. One of the rangeland studies that we have implemented here at the Texas A&M AgriLife Research Station in the southwestern Edwards Plateau is the “Sonora Flex Project”. Briefly, it is a comparison between two different rangeland management strategies; 1) an adaptation of the Merrill Four Pasture -Three Herd grazing system, and 2) a Continuous Multi-species Grazing with Patch Burning system. Now, I know some of you will balk at calling continuous grazing a “system” but on a continuum of grazing management decision making intensity, I submit that it qualifies on the lower end. At any rate, we currently have one replication of each treatment that we started last November, and we plan to have another replication of each in place by the end of the calendar year. We have collected animal condition and production data though one production cycle for breeding Dorper ewes and mature Angora wethers. Rangeland soil and vegetation condition data has been collected on this particular set of pastures, for this study, for two years. The study is intended to be long-term and will eventually provide replicated working landscapes and a living laboratory for a variety of scientific disciplines. And, hopefully many useful documents available in the Rangelands Gateway.
We chose these two treatments for several reasons. One being that the original Merrill system pastures are still intact at the Sonora Station and this system is still in use across the region. Continuous patch burn grazing is also increasing in adoption throughout the southern plains and it is relatively easy to implement. More applied research is needed on this strategy in our savanna ecosystems. The Sonora Flex treatment involves a combination of best management practices: a) collaborative adaptive management, b) livestock grazing deferment, c) prescribed fire, d) multispecies grazing, and e) drought capacity base-herd stocking rate. We will also employ the same basic rest/rotation of the Merrill System with the exception that one pasture is designated to hold the “flex” herd. Depending on the conditions of the year, “flex” could be additional stockers, prescribed fire, additional rest, or drought relief grazing. Continuous Multi-species Grazing with Patch Burning will employ similar collaborative adaptive multi-species grazing and fire management but with no deferment.
So, even with the “flex” component, I am sure all of this sounds very familiar and not unlike any number of other grazing management studies. Understood. But, here is where this study will be a little different. We will manage both “systems” with the intent to meet established animal and land production or stewardship goals in each. So, if there will be no difference in outcomes, then why do the study? Because if a land-owner/manager implements a management strategy, theoretically they will set goals and manage to achieve them. Both of these management strategies will likely be “successful” in obtaining a desired weaning weight or mohair clip. Both should maintain a desired end of season standing crop or long-term woody plant canopy cover. What we will measure as our response variables are primarily economic inputs required to meet established production goals. How much labor or feed was required in each system? How often was I able to accumulate fuel and conduct a burn? How often did I need to apply a mechanical or chemical woody plant treatment? Etc… So, this will be as much of an economic and management study as an ecological one. And I contend that the ecological knowledge we obtain on these working landscapes, within the context of cost:benefit, will be extremely valuable to future rangeland stewards. Equally valuable will be the experience and peer to peer knowledge transfer that comes from the collaborative adaptive management aspect. Stay tuned.”