Rotational cattle grazing technique does not improve plant diversity, study suggests

(Kara Oosterhuis/RealAgriculture)

Ranchers who employ multi-paddock grazing for cattle do so for many reasons, but a new study from the University of Alberta suggests the practice doesn’t significantly improve plant diversity on the land.

A research team led by Jessica Grenke, PhD candidate in the Department of Biological Sciences, compared adaptive multi-paddock grazing, called AMP, with other grazing systems more common in the northern Great Plains.

AMP is a specialized rotational grazing practice that’s intended to emulate historical grazing patterns of large herds of animals moving rapidly across the landscape, leaving a long recovery period before being grazed again.

While complementary studies by U of A researchers in this multi-pronged project have found ranches using AMP grazing practices have a number of benefits including higher water infiltration and thus better resistance to drought, the practice doesn’t improve plant diversity.

The lone negative effect was a small reduction in the total number of native plant species found within each ranch, which may reflect an intolerance of endemic plant species to AMP grazing.