Enhance Ranchland Profitability by Feeding Soil Microbes
Podcast Notes
“If you break out the fungal hyphae and you disturb microbiomes, they won't be able to develop, establish, and flourish from that point on.…we realized how important it is to have the fungal community in the system.”
David Johnson is a molecular biologist and research scientist in Las Cruces NM, investigating soil microbial community population, structure, diversity and biological functionality and their influence on plant growth and soil fertility development in farm and rangeland ecosystems. While working on a project that involved composting excess cow manure that needed a lot of turning, David brought home a lot of dirty laundry. David’s wife, Hui-Chun Su-Johnson, says she grew tired of washing David’s clothes from turning cow poop, and this changed their lives.
David and Hui-Chun started to work on the idea of a compost system that was aerobic, yet did not require turning – a tall order indeed. Hui-Chun joined David in the field and the couple co-developed the no-turn, aerobic Johnson-Su Bioreactor (compost system) that provided a fungal-dominant, biologically diverse compost. The use of Johnson-Su Compost, integrated with land management, then became known as BEAM, or Biologically Enhanced Agricultural Management. What started off as an effort to reduce the laundry load in the Johnson household resulted in a unique compost with a global following (for example, see the Johnson-Su Facebook group)!!
Given that ruminant animals are also “great composting machines”, the Johnsons turned their attention to examining the biological benefits of Adaptive Multi Paddock (AMP)Grazing Systems. AMP is based on the use of ruminant animals to mimic nature not unlike what we may have found a few hundred years ago as bison roamed the prairie in herds that constantly moved in search of food and were kept tight by predators, leaving behind urine, dung, and hoofprints and other animal residue that fed soil organisms. The leftover grass, trampled by bison hooves, covered, protected and fed soil microbes, especially fungi, facilitated the capture and incorporation of more organic matter into the soil profile. In short, this process of herds of ruminants moving through the landscape “inoculated the soil as the bison passed through each area.”
Whether you call it Adaptive Multi Paddock grazing, or Adaptive Management, the watchwords for this process are: Observe, Adapt, Repeat. Each area is different. Each herd, each ranch, each pasture is different, and each day’s weather is different. The key to moving this system forward in the regenerative process lies in observation and subsequent adaptation.
In 2022, Johnson and colleagues produced another peer-reviewed article on the benefits of AMP grazing. This research, based on 5 paired across-the-fence pastures (one conventional pasture, one AMP pasture) in the Southeast, fit nicely with similar efforts across the country with a group of researchers that include Richard Teague, Steven Apfelbaum, Ry Thompson, and Peter Byck (also co-authors with Johnson). This group is conducting other across-the fence experiments, on real farms and ranches, in different parts of the United States and Canada, keep an eye out for their names, also see a list of some of their peer-reviewed articles at the end of this piece.
Results from the Johnson et al. study showed (1) AMP grazing systems significantly outperformed their conventional across the fence counterparts in standing crop biomass (2) increased fungal/bacterial ratios and (3) increased predator/prey ratios. This means that ranchers converting to AMP grazing strategies will see improved soil structure, improved forage production, increased soil organic matter, improved nutrient efficiency along with increased resilience of their systems to weather extremes.
To be sure, AMP grazing is an appreciable departure from conventional systems and what was considered “the right way” for decades. “But now that we have more information out there as tools for [producers], hopefully there will be more ways to show people that there is a more defined, more reliable path.” Says Johnson. He continues: “For [producers] to transition to regenerative and be profitable will only be positive and beneficial for everybody when they are able to make more money and be a better steward of land.. it's all positive feedback loop…and I think we just need to find a way to show people that OK, here is a path that you can go forward with or without having to take on so much risk of unknown.”
More science like this is making its way to peer review literature, validating what some regenerative ranchers and farmers have known and practiced for decades. This science, paired with living working examples on farms and ranches across the country, across the globe, provides more evidence and incentive for producers to rethink their business models for the better.
