New research from the Borderlands Research Institute at Sul Ross State University highlights how grazing practices directly influence underground ecosystems critical to rangeland sustainability. The study, conducted on the Dixon Water Foundation’s Mimms Ranch near Marfa, Texas, shows that rotational grazing significantly enhances colonization by mycorrhizal fungi—microscopic organisms essential to plant health and soil function.
Mycorrhizal fungi form symbiotic relationships with plant roots, expanding their access to nutrients and water—key benefits in arid regions like the Chihuahuan Desert. These fungi support drought resistance and nutrient cycling, strengthening ecological resilience in harsh climates.
Researchers Asia Cornelius, Carlos E. Gonzalez, and J. Silverio Avila-S. compared mycorrhizal colonization under rotational and continuous grazing systems across two soil types: Marfa Clay Loam and Musquiz Clay Loam. They found that rotational grazing increased fungal colonization by 22% over continuous grazing. Soil type had less impact on colonization than grazing system, although Musquiz soil showed a slight advantage when combined with rotational grazing.
“Rotational grazing allows pastures to rest and recover, which reduces soil compaction and maintains vegetation cover—both critical for healthy fungal networks,” the authors wrote.
Continuous grazing, by contrast, was linked to soil degradation, reduced plant diversity, and compacted conditions that hinder fungal growth and root development. While manure deposits can create nutrient-rich patches that benefit some organisms, over-enrichment may cause plants to rely less on mycorrhizal partnerships, diminishing long-term soil health.
The study encourages ranchers in West Texas and other arid rangelands to adopt rotational grazing as a strategy to enhance not just livestock productivity but the resilience of entire ecosystems.
“Supporting mycorrhizal fungi through sustainable management practices benefits both the land and the people who rely on it,” the researchers concluded.
The findings underscore the importance of integrated soil monitoring, conservation partnerships, and grazing plans that account for biological processes below the surface—where much of a rangeland’s strength begins.
