Regenerative Ranching: Analyzing the impact of specific variation in rotational grazing practices on pasture health and biodiversity

Abstract

Rotational grazing, or paddock grazing, is a form of regenerative agriculture where livestock are regularly moved among pastures. In a time of increased environmental degradation and agricultural expansion, it has the potential to be a sustainable alternative to the destructive overgrazing commonly found in industrial livestock rearing. While studies have suggested that implementing intense short-period grazing with prolonged periods of rest can increase plant diversity and biomass, the efficiency of this practice has been argued by practitioners in the United States for about seventy years. This study aimed to address how rotational grazing farmers’ management decisions, such as time left between grazes, impact groundcover and arthropod communities on a small scale. The study included data collected from two ranches in southeast Michigan implementing intensive rotational grazing, meaning moving the herds daily. Through sweep net and pitfall sampling, pastures were monitored pre- and post-grazing over an entire grazing season. This was collected along with quadrat sampling of vegetation height, diversity, and groundcover percentage to paint a fuller picture of ecological impact. From this information, how pasture recovery is affected by time since last graze, grazing frequency, and livestock type (cattle, sheep, or chicken) was analyzed. There was a significant increase in several vegetation and arthropod measures in response to increasing time since last grazed as well as a significant farm-specific effect, which could be attributable to factors such as soil type or site history. Faster recovery at the farm with the longer grazing history suggests that long-term implementation of rotational grazing as continued disturbance through grazing could be correlated with increased pasture resilience. Other variations in grazing management including grazing frequency and livestock type were found to significantly influence vegetation communities. This underscores the complexity of rotational grazing management and the necessity for a nuanced understanding of its effects on pasture health. These findings have implications for new farmers considering adopting rotational grazing. Specifically, with prolonged adoption of rotational grazing there appears a possibility to sustain larger livestock populations on more compact acreage while decreasing reliance on supplemental hay. All of these outcomes have the potential to help offset the initial cost and effort of transition to rotational grazing and could act as an encouragement for potential farms.