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Conservation Grazing for Land Stewardship

sheep will eat invasive plants
Photo credit: Gary Kleppel, University at Albany

Controlled grazing by domestic livestock is a sustainable alternative to herbicide or mowing for control of invasive plants in natural areas. The use of sheep or goats to graze invasive plants can not only help meet DEC goals of pesticide reduction, but can also improve plant biodiversity and soil health. Grazing can be an effective substitute for mowing (especially in areas too steep to mow safely), while also reducing fuel costs, and minimizing plant litter and thatch. In areas with sensitive wildlife populations, managed grazing can be much safer for wildlife than mowing.

The growing popularity of targeted grazing for invasive plant control, especially in the Western United States, has helped change the impact of grazing from land degradation to ecosystem restoration.

Visit the University of Idaho website for a handbook on targeted grazing (leaves DEC website).

Grazing on State Lands

DEC worked with Dr. Gary Kleppel at the University at Albany to develop a conservation grazing protocol for State lands, the first of its kind in the United States. The process uses a technique called Intensive Rotational Targeted Grazing (IRTG). The animals are managed with portable electric fencing, and rotational grazing techniques that minimize impact on the land. While the draft guidance document focuses on the use of sheep, the basic principles can also be used for management of goats and even for larger animals such as horses and cattle.

Conservation Grazing Uses

  • Controlling invasive plants: Almost all of New York's invasive plant species can be eaten by livestock - even giant hogweed.
  • Reducing fuel load: To reduce fire danger, and to prepare for manageable controlled burns.
  • Removing woody vegetation and conducting grazing maintenance at historic sites: The National Park Service has been using goats at Fort Wadsworth on Staten Island.
  • Cleaning up edges and fence lines: These are often havens for poison ivy. Sheep and goats love poison ivy!
  • Restoring wildlife habitat: Much prime wildlife habitat is a mix of fields and patches of early succession brush and trees. Without maintenance, it will quickly go to thick brush and young trees. Grazing is very effective at keeping open areas open and increasing overall habitat diversity.
  • Grazing capped landfills: To prevent growth of brush and trees with deeper roots, which could damage the cap.

Intensive Rotational Targeted Grazing

Intensive rotational targeted grazing is an ecologically sound management practice used to control the spread of invasive plants with the deployment of grazers like goats, sheep and cattle. The grazers are rotated between several plots of land at 2-3 day intervals (12-30 days completes one full rotation cycle among all plots). Within a particular plot, the grazers feed on grasses, plants, woody shrubs, and most importantly, invasive plants that have spread rapidly in the area. The animals graze in the plot until most of the vegetation is trimmed down, then they are herded into a separate plot to do the same thing while the previous plot has time to grow back and replenish itself for the next grazing cycle. This process helps native plants compete with invasive plants by leveling the playing field.

Benefits of IRTG

  • Suppresses and controls the rapid spread of invasive plants
  • Increases biodiversity - the number of different (native) plant species in a community has been shown to increase with grazing
  • Requires a small amount of fossil fuel use
  • No toxic chemicals are used
  • Not dependent on heavy machinery or intensive manpower
  • Grazing infrastructure is inexpensive
  • High level of control
  • The management plan can be discontinued at any time
  • Mimics a natural pattern, so the ecosystem is not disrupted
  • The need for grazing is expected to decrease over time as the native plant community stabilizes and soils improve

Limitations of IRTG

  • Not all landscapes are suitable for implementation (cannot be placed along roadways, and wetlands are too wet for the health of the livestock)
  • Repeated treatment is necessary for several years
  • Can disrupt soil health from compaction by excessive trampling for long periods of time. By using smaller plots, more animals, and a quicker rotation time, compaction problems can be avoided.