A Symposium on Rotation Grazing in North America

by Arthur W. Sampson

from the Journal of Range Management, Vol. 4, No. 1 (Jan., 1951), pp 19-24.

In January, 1950 at the annual meeting of the Range Society, rotation grazing was one of the subjects discussed in detail.  Because of the lively debate, diversity of opinion, and confusion of terminology, it was requested that articles be submitted for the Journal of Range Management to help draw some conclusions that were more clearly defined for everyone concerned with the subject.

The article makes clearer the definitions that seemed to cause confusion: rotation grazing, deferred grazing, deferred rotation, and alternate grazing.  Rotation grazing is shifting the livestock systematically at desirable intervals to different subunits of a range area or fenced subdivisions, and back to the first subdivision, without specific provision for seed production.  The goals of rotation grazing are to avoid grazing the same subunit first each spring and to maintain plant cover in the entire range area.  Deferred Grazing can be defined as any prescribed delayed date for placing animals on a range subunit.  Deferred-rotation is any rotation system which promotes delaying grazing on a subunit until after seed maturity for purposes of revegetation.  And alternate grazing is where a range area is divided into two subdivisions to improve the vigor of vegetation.

Sampson has listed nearly fifty articles in his bibliography to support his findings but only lists a few to help point out his conclusions.  Results of all the experiments were mixed.  One finding stated that a preliminary system of deferred and rotation grazing improved land in Oregon.  Another case found that vegetation was improving , but animal performance was better on the properly stocked continuously grazed pasture.  In a third case, two experiments were conducted, one on a continuous grazing pattern, another using rotation grazing.  However the stocking rates were not consistent enough to draw a strong conclusion.

The article draws five general conclusions from the study they conducted.  First is that deferred grazing every three years on bunchgrass range is beneficial to vegetation.  Second is that some form of rotation grazing is essential on bunchgrass ranges and mountain lands with a shorter growing season.Third, that natural revegetation of bunchgrass range that has been depleted  is generally unsuccessful in the mountain ranges with rugged topography because the more accessible portions will be over-grazed and the steeper slopes will not be cropped enough.  Therefore, the improvements are slow and costly.  Fourth is that if anyone practicing a system of rotation grazing needs to ensure that animals are not grazing the same portion of the range at the same time every year, especially during early spring grazing.  Finally, the benefits derived from rotation grazing need to take into account the economic returns as well as the costs incurred such as fencing, water, etc.  These expenses are higher on mountain bunchgrass and many critical areas.

For perspective, this article was written in 1950 and includes references to trials as far back as 1913 in many different countries.  Since that time, while much has been learned, this same debate continues.  What is striking is the realization, even then, of the myriad ways in which rangeland can be actively managed via the application of grazing planning principles.  Already people were talking about modifying timing schedules and adequate recovery.  Now Holistic Planned Grazing offers all of the tools required to manage and monitor these variables.

The tone of this article suggests a sense of openness on the part the broader range science community of the time.