Roger Gates: Mob grazing & diet selections
May 31, 2012
I’m reading For the Love of Land, a book recommended by one of my range scientist colleagues. I agree with his assessment that it’s one of the best contributions to rangeland management and restoration that I’ve recently been exposed to.
For the Love of Land is a collection of columns written by Jim Howell for “In Practice,” a bi-monthly periodical from Holistic Management International. Howell was raised on ranches in California and Colorado and has managed grazing livestock operations in Colorado, east Texas, southwest New Mexico and has carefully observed operations around the world including Argentina, Australia, Zimbabwe, South Africa and New Zealand.
Howell’s penetrating ability to “connect-the-dots” between research results from experiments conducted with grazing animals and grazinglands and the practical, prescriptive application of ecological principals to ranching lead to two comments that I found particularly helpful.
The first is that grazing livestock producers should “move toward” mob grazing practices. Following a description of benefits he has experienced on operations he was managing and observed internationally, Howell suggests that plans to incorporate those benefits would be rationale. In his experience, practices which include minimizing the number of grazing herds, concentrating livestock at high densities and moving them frequently have contributed to better utilization of the resources available and substantially increased duration of recovery periods.
Howell identifies important principles demonstrated in the North Dakota research which examined “twice over” rotation. In the Northern Plains, production of cool-season grasses is greatly influenced by new tillers which develop in the fall. Howell relates how aggressive use of fall pastures on his high altitude Colorado ranch diminished spring production the following year. The observation validates research findings and underscores the importance of planning which accounts for plant recovery.
Howell is adamant that “moving toward” mob grazing must result from a careful planning process which considers all of the complexities which are integral to ranching. Adopting “mob grazing” or high-density stocking as the most current “progressive ranching practice,” without a consideration of potential negative consequences, is foolish at best. However, “moving toward” mob grazing suggests gradual implementation of practices that, after thoughtful consideration, make sense for a particular operation.
I consider one holistic management principal particularly appropriate following the implementation of a new practice. That principle is to “assume you are wrong.”
Human nature being what it is, when we thoroughly investigate and carefully plan a new practice, such as a more intensive grazing rotation, we are inclined to proceed believing it was the right decision. If unexpected or negative results occur, the inclination is to look at other causes for an explanation and perhaps a correction.
If, on the other hand, we implement the practice and “assume we are wrong,” we are much more likely to carefully monitor impacts of the new practice. Careful observation and measurement of “before and after” will either verify that the procedure is operating successfully; identify factors that can be improved; or reveal errors in planning or implementation that resulted in poor outcomes.
A second comment that I found particularly helpful was Howell’s discussion of animal behavior and diet selection and the relationship to planning or orientation of grazing patterns.
Howell credits the research of Fred Provenza for describing the principals that can be very helpful in designing specific grazing systems. Again he points to his own experience with a system that didn’t work as expected. Research and observation by Provenza and his colleagues have identified the elegant capacity of grazing animals to select an optimum diet when offered a landscape with considerable diversity.
In the process of “moving toward” mob grazing, it is likely that physical pasture size will become progressively smaller (i.e. more pastures, greater livestock concentration, more frequent rotation).
Arid landscapes are often characterized by “patchy” vegetation. Plants with particular growth requirements are likely to be concentrated in “patches” rather than uniformly distributed. As pastures become smaller on such landscapes that diversity of vegetation available for animals to select from is reduced, restricting their ability to optimize their diet and consequently reducing performance.
Rangelands in the Northern Plains can be incredibly diverse when they are healthy. Nonetheless, being alert to the dietary consequences of pasture subdivision is something I had not considered.
For the Love of Land has many lessons available for the reader. I recommend it for stimulating your curiosity – it certainly challenged me!