Why Grazing Ruminants

Since studying agronomy at the University of Manitoba several years ago the farmer in me become fascinated with soil carbon and soil organic matter (SOM).  It seemed that SOM was the one thing that could affect everything that concerned the success of the farm.  Things like water holding capacity of the soil, nutrient retention and cycling, and soil structure are all directly related to the SOM content.  All these things buffer against the farmer’s arch nemesis, the weather, and can be directly correlated to inherent productivity and profitability of the farm.  Only problem is that traditionally it can take several years, decades or more, to significantly increase the carbon content of the soil. 

We know that agricultural soils were once much richer in SOM than they are today.  A review paper by Dr. Henry Janzen gives examples of the SOM content of soils across the prairies over a 100 years ago and many soils having SOM levels over 10%.  How did these soils develop to have such high carbon content?  Diverse grassland ecosystems of which grazing ruminants where an integral part.  In recent years there has been much interest and talk of rapid increases in soil organic matter and this seems to be stemming from the Regenerative agriculture movement focused on mimicking these natural prairie ecosystems adhering to the principles of soil health.   The scientific literature agrees that a more diverse system, even considering a three or four crop rotation compared to one or two crops, will be beneficial to the carbon status of the soil.  However, what some farmers are finding when they incorporate livestock into an already diverse system are that the results in the field can be profound and carbon appears to be increasing much quicker than has been historically accepted as possible.  On my Nuffield study I plan to seek out innovative farmers and researchers that have embraced the systems approach and are working with ruminants to capitalize and foster rapid improvements to their soil and associated benefits to productivity and profitability.

Cattle grazing a diverse annual polycrop on South Glanton Farms.