Short Duration Grazing and the Savory Grazing Method in Perspective
Authors: Heitschmidt, R. Walker, J.
Published: Rangelands, Vol. 5, No. 4. (Aug., 1983), pp. 147-150.
This article is an excellent summary of the controversy related to Holistic Planned Grazing (HPG), then referred to as the Savory Grazing Method. The authors analyze the relationship between grazing management and range productivity, and are concerned with productivity as a function of three variables: amount of forage produced, forage quality, and the efficiency by which the forage is harvested.
They argue that grazing management is designed to “control the frequency and severity of defoliation of individual plants.” They also conclude: “Since a major portion of the success of all grazing systems is directly related to their ability to control defoliation, it follows that short duration grazing offers the greatest potential for increasing rangeland productivity.”
The authors disagree with the contention that Holistic Planned Grazing allows the doubling of stocking rates. They suggest that the “frequency and severity of defoliation will always increase with stocking rate because grazing pressure will always increase unless total available forage also increases.”
In this context, the contention that animal impact and herd effect will hasten the advance of plant succession is challenged: “Although some physical animal impact may be beneficial and thus desirable, there is little if any scientific evidence suggesting that it is as important as controlling frequency and severity of defoliation” (emphasis is the author’s).
Citing a study by Blackburn et. al. in 1992, the argument is made that increased livestock grazing actually increases bare ground, decreases soil organic matter, increases surface crusts and erosion. It is doubtful, however, that the land under management for these studies was managed holistically, or that there was an attempt to quantify the influence of animal behavior.
The authors point out that increasing stocking may in some cases stimulate new plant growth and forage quality via the removal of dead standing material. Additionally, they note: “More efficient use of the forage already available is probably the major reason that stocking rate can, in certain instances, be immediately increased when implementing [Holistic Planned Grazing]….which will improve the ability of the livestock to search all areas of a pasture and more effectively utilize all available forage.”
The authors also note the fact that applying HPG will intensify managerial control, thus enhancing the prospects for success.
Since 1983 our understanding of the effects of Holistic Planned Grazing has grown. Yet even today the science of herd effect and animal impact remains elusive. This is, in part I believe, a consequence of not having the right tools to adequately measure these relationships. With the advent of GPS, GIS, and other information technologies, we are now developing innovative ways to keep track of these variables.
Even this somewhat critical paper concedes many important points. First, that HPG does indeed have the potential to improve range quality, primarily by empowering the manager to control the frequency and timing of defoliation, and also allowing a more efficient and controlled utilization of grass biomass. These are important points that have been validated elsewhere.
Finally, even where disagreements do exist, we can see that those details are too often highlighted at the expense of areas where we do agree. In concluding, the authors state: “Realistically the only point of controversy is rate of stocking which is related to differences in opinion of the conceptual validity of the principle of physical animal impact. We simply suggest that proponents of [HPG] tend to underestimate the negative impacts of heavy rates of stocking and overestimate the positive impacts of grazing livestock on arid rangelands.”
Unanswered questions must drive current and future research. We do know that the shift to holistic thinking can improve biodiversity, and the proper application of holistic planned grazing increases managerial control. But the responses of complex ecosystems to differing management treatments are still poorly understood. This is greatly complicated by the infinite interrelationships between human management and nature.
Specific management decisions that make Holistic Management effective in one environment, practiced by one manager, may not be the same decisions that make it effective elsewhere. Nevertheless, the best decisions are made when they are informed by the best, most up-to-date information. We must therefore continue to study the ecosystem effects of timed defoliation and recovery, controlled utilization, physical animal impact, and herd effect.