Angus cattle on pasture. Click the image for
more information about it.
From Dirt to Diamonds
July 29, 2005
Carbon stored in soil during the first
five years of bermudagrass management was two to three times greater when the
grass was grazed than when it was harvested for hay or left unharvested,
according to Agricultural Research Service (ARS) scientists.
Carbon dioxide in air is important for life on earth, but its rapidly rising
concentration is cause for concern, because of its contribution to the
greenhouse effect and potential global warming. Maintaining more carbon in soil
means less of it escapes into the atmosphere.
Franzluebbers and animal scientist
Stuedemann of ARS found that cattle grazing on forage grasses could help
improve carbon storage in soil. In studies at ARS'
Phil Campbell, Sr. Natural Resource Conservation Center in Watkinsville,
Ga., they found that adding cattle grazing to a crop rotation system can be
beneficial by enriching the soil with carbon and other nutrients. Also, income
could be generated from the cattle.
In Georgia, plowing and other practices have resulted in lost top soil.
Fortunately, permanent pasture now accounts for about 18 percent of land area
in the southeastern states, compared to 20 percent for cropland. Converting
land to permanent pasture has significantly reduced soil erosion.
In most instances, crop farming and cattle farming are separate operations.
Franzluebbers and Stuedemann envision a system where calves could be raised on
pasture in rotation with other crops like corn or wheat. The type of crop would
determine when grazing would occur.
According to the researchers, putting as little as 10 percent of existing
cropland in rotation with grazing could significantly reduce costs, due to
lower inputs such as herbicides, and generate additional income from the
livestock. The next step for the researchers is looking at long term
integration of annual crops with perennial grasses.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.