Beef yield and pasture utilization have a significant impact on the potential to sequester carbon in a pasture, because of their impact on forage quality and ultimately nutrient cycling. Impact of grazing management on residue quality and carbon sequestration Microorganisms in the residue and litter break down and decompose residue organic matter of high forage quality faster than forage of low quality, just as rumen microorganisms do. Contribution of root material to soil carbon Roots contribute directly to the formation of organic carbon, because they don't go through the secondary process of grazing. However, they are subjected to the same microbial degradation processes as the above ground residue. This is because perennials tend to produce more root material than annuals in a year and because the life span of roots may be longer than a year, allowing them to accumulate.
Extensive pastures tend to have roots with longer life spans than intensive pastures.
In this study the intensive old grass pasture has accumulated the most root dry matter and carbon, significantly more than the low input old grass. Although meadow bromegrass-alfalfa produced the most top growth and the most beef, it did not accumulate equivalent root dry matter and carbon to alfalfa, which was the same age. However, all perennials accumulated from 2 to 5.3 times the root carbon as the annual pasture. Ultimately this will be reflected in quantities of soil organic carbon stored or sequestered. This data does not imply that the old grass pastures produce more root material each year than the other treatments.