Modern Grazing Practices: Who Knew Population Growth Curves Were So Useful?

A couple of years ago I visited  a young rancher who was using innovative practices to graze his cattle and nurture his land.  These included not only maintaining pastures of diverse grasses, but also moving the herd from place to place, more closely simulating the movements of the West’s great ruminant herds.  In this way, the land and its grasses were allowed to recover.

He gave us a tour, showing the different grasses, many of them native,  growing intermingled.  Inspection of a shovel full of soil showed a lot of organic matter was present.  At a molecular level, the grasses were sequestering carbon in great quantities.

Then he explained the moving of the herd to different grazing areas.  And the population growth curve played an essential role in this practice!  Who knew!  As the cattle eat the grasses down, the height soon reaches a point where most of the photosynthetic surface of the grass blades is gone, and the grass is in the lag phase of its growth.  When it has grown enough to have more area for photosynthesis, its growth takes off again, entering the exponential phase of the growth curve, and it quickly recovers.  So the secret lies in excluding the cattle from a grazing area just before the grass is short enough to be in the lag phase.  This way it will be in the exponential phase, growing quickly for the speediest recovery of height (biomass) and food for the cattle.

A very practical and efficient use of the growth curve!

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