EXT 7 Impacts of cattle grazing on the proliferation of foxtail barley in wet meadow rangeland communities

 

Project Details

  • Project Lead: Rafael Otfinowski, Assistant Professor, Department of Biology, University of Winnipeg
  • Collaborating Partners: Jane Thornton, Farm Production Extension – Forage and Pasture, Manitoba Agriculture
    Kim Wolfe, Research Development Specialist, Manitoba
    Agriculture
  • MBFI Location(s): First Street Pasture
  • Start Date: 2016
  • Status: Completed September 2017

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Objectives

This research will examine the response of wet meadow plant communities to the intensity and timing of grazing in order to evaluate the impact of cattle on the proliferation of foxtail barley. Plant community measurements will be supplemented with measurements of soil compaction, moisture, and salinity. By evaluating the impacts of cattle grazing on wet meadow plant communities, this project will help increase the use of wetland meadows as summer forage, while potentially reducing the proliferation of foxtail barley, a noxious weed.

Introduction

Wet meadows constitute a large portion of Manitoba's native rangeland communities. Through the diversity of the native plants they support, wet meadows produce valuable forage and help maintain important ecological functions. For example, high root biomass of meadow species helps regulate soil moisture, sequester carbon, and sustain the biological activity of soils, including the cycling of nutrients. Despite the extent of wet meadow rangelands across Manitoba's ecoregions, little is known about the response of these plant communities to cattle grazing. Of special concern is the possibility that grazing contributes to the proliferation of foxtail barley (Hordeum jubatum), a weedy, salt-tolerant graminoid, considered noxious in Manitoba. Characteristics of saline, wet meadows, foxtail barley invades disturbed pastures, where it is difficult to control and poses a threat to grazing animals.

One focus of this research explores the potential to use cattle grazing to manage the proliferation of foxtail barley. Gazing of native range communities modifies both the composition of plant species that affect the ecosystem services they provide. For example, changes in the longevity, leaf dry matter content, and leaf nitrogen of grazed rangeland communities increase their productivity, accelerate the cycling of nutrients, and increase the sequestration of carbon in the soil. Ongoing research illustrates that plant height, life cycle, and vegetative reproduction vary in response to grazing intensity and that healthy rangelands are more successful at resisting invasions by weedy species. By focusing on the impact of cattle grazing on wet meadow plant communities, this research will help establish links between the timing and intensity of grazing disturbance and the proliferation of foxtail barley. Findings from this research will help sustain the productivity of wet rangeland communities in Manitoba.