New research from the Borderlands Research Institute at Sul Ross State University is shedding light on how different grazing strategies affect vital underground ecosystems in the Chihuahuan Desert. Conducted at the Dixon Water Foundation’s Mimms Ranch near Marfa, the study found that rotational grazing significantly improves colonization of mycorrhizal fungi—microscopic soil organisms essential to plant health and ecosystem stability.
Mycorrhizal fungi form symbiotic relationships with plant roots, expanding access to nutrients and water, and improving drought resistance. In arid regions like the Chihuahuan Desert, these fungi are critical to maintaining productive rangelands. The study compared rotational and continuous grazing systems on two soil types—Marfa Clay Loam and Musquiz Clay Loam—and found that grazing system had a larger impact than soil type on fungal colonization.
Blue grama, a dominant forage species in the area, showed 22% higher colonization under rotational grazing on Marfa soil. On Musquiz soil, colonization was 10% higher than in Marfa soil under continuous grazing, with an additional 3% increase when rotational practices were applied.
The researchers concluded that rotational grazing—by giving pastures time to rest—reduces soil compaction, preserves ground cover, and supports the fungi’s growth. In contrast, continuous grazing can degrade soil conditions, reducing pore space, plant diversity, and ultimately the resilience of the landscape.
The findings encourage landowners and ranchers across West Texas and other arid regions to prioritize grazing strategies that maintain ecological balance. Integrating soil health monitoring into ranch management plans can further support sustainability efforts.
As pressures from climate change and land-use intensify, understanding and protecting these underground networks may be key to preserving both ranching traditions and desert ecosystems for generations to come.
