Livestock management in grazed watersheds: A review of practices that protect water quality.

Melvin R. George, Technical Coordinator

UC Davis Animal Agriculture Research Center and UC Agricultural Issues Center, University of California, Division of Agriculture and Natural Resources, Publication 3381. 1996

Editor’s note: This publication follows the UC Agricultural Issues Center/UCD Animal Agriculture Research Center conference, Animal Agriculture Impacts on Water Quality in California (reported in Sustainable Agriculture, Vol. 7, Nos. 1 and 2). The report was developed as part of a cooperative project between the University of California-Davis, Oregon State University and the University of Nevada-Reno. This project, entitled “Protection of Sensitive Watershed Areas by Improved Animal Production Systems,” was funded by the U.S. Environmental Protection Agency’s National Exposure Research Laboratory Ecosystems Research Division in Athens, Georgia.

The complexity of the farming or ranching system is often the most difficult fact to contend with when trying to analyze and resolve concerns about agricultural production and environmental health. The information one needs to address these issues and problems is often inadequate or imperfect, and one must be willing to deal with the inexact science of human behavior and culture.

This report does an admirable job of dealing with these challenges as they relate to water quality in grazed livestock systems in the Western U.S. The authors approach the current situation from the perspective that “...there are many streams and riparian areas that can support grazing with proper management; but there certainly are situations where even the lowest level of grazing will adversely affect the stream, its riparian zone and even its watershed. We can only strive 1) to understand the stability and productive potential of rangeland ecosystems and their associated riparian areas and streams, and 2) to apply that knowledge in developing effective grazing strategies that meet management goals.” (page 5)

In trying to reach water quality goals, it is clear that there are no recipes. Each stream, ranch, community and watershed system is unique. Yet from all the work on this subject over the past decade, some general management principles emerge. These management practices, according to the authors, are both art and science, and should be based on values and a vision for the future. In addition, ranchers will need to be flexible in implementing these practices because ranching systems are so dynamic.

In order to identify the best practices to redistribute grazing pressures in a watershed, the report notes that it is essential land managers ask these key questions:

• What is the topography of the allotment or pasture?
• Does the riparian area contain the only flat or gently sloping land?
• Is water available away from the riparian area?
• Can water be developed far enough from the riparian area to reduce trailing in between?
• If we reduce livestock use of the riparian area, will management objectives be met—or are there other barriers?
• Can livestock distribution practices provide sufficient “cow habitat” in the form of water, forage, shade, gentle slopes and other amenities to attract cattle away from the riparian zone?
• Are there animals in the herd that are “riparian huggers” or that lead the herd back to sensitive areas?
• Are there times when riparian grazing is not harmful, or is beneficial?
• Are there public policy rules and regulations that prevent timely response to management opportunities and hazards?
• Are the practices economically feasible?

These questions are revisited throughout the report, as the authors address six topics in detail. The section titles (with respective authors) are:

• Developing an Effective Grazing Strategy for Riparian Vegetation (Bill Krueger)
• Reading a Stream’s Need for Management (Sherman Swanson)
• Management Practices to Change Livestock Behavior in Grazed Watersheds (Melvin George)
• Controlling Season, Intensity and Frequency of Grazing (John C. Buckhouse)
• Survival and Transport of Fecal Pathogens in Grazed Watersheds (Royce Larsen)
• Grazing and Ecosystem Management (Bill Krueger)

The report recognizes that there are many unanswered questions about stream and riparian systems and how they respond to different land management practices. But, as the authors state, it is often not possible to delay management decisions while waiting for answers. The authors address this dilemma by suggesting ways to evaluate some of the different practices that redistribute livestock. They offer their own general assessment of the impact of several alternatives:

• Season-long grazing—detrimental to both herbaceous and woody vegetation; animals are present to graze each plant species at its susceptible stage of growth without any planned rest;
• Rotation or deferred-rotation grazing—seems to combine the attributes of simplicity and plant protection to promote herbaceous growth, and in some instances woody vegetation;
• Late-growing-season grazing—before the fall rains, generally promotes herbaceous vegetation health; may reduce soil compaction and promote habitat for ground-nesting birds; may be inappropriate for promotion of streamside woody vegetation;
• Dormant-season and early-growing season grazing—may promote both shrubs and herbaceous vegetation; be alert to potential problems like lowered nutritional value requiring supplementation; soil compaction problems may result, depending on soil moisture and frost conditions; opportunity to reduce winter feed costs by grazing at this time may provide economic advantage.

Grazing management is a component of ecosystem management. As such, land managers need to put their management decisions into the right context. The first step, according to the report, should be to determine a vision of success. What will the landscape look like? How will water quality, yield, nutrient cycling and other aspects of sustainability be affected? How will people benefit? Various resource management planning processes have been developed and are available to ranch and land managers. No matter which one you choose, according to the authors, “The keys to successful management are 1) develop the vision, 2) design management according to the vision, and 3) emphasize communication and mutual understanding. Involvement of the people is key, since people will support what they create themselves.”

For more information: Mel George, Department of Agronomy and Range Science, University of California, Davis, CA 95616.

(DEC.545) Contributed by Bill Liebhardt