Posted: 03 Nov 2015 06:09 AM PST
Reducing greenhouse gas emissions in the Southern Great Plains could require a change of grazing management by traditional cow-calf producers, according to a new study…. Ruminants, particularly beef cattle, are perceived by many as a problem since they are a source of greenhouse gas due to the methane produced by rumen fermentation, Park said. “We believe that conclusion is premature until full ecosystem analyses have outlined the net emissions by considering all emissions compared to carbon sequestration associated with different options in the beef production chain,” Teague said.
In this study funded in part by the Dixon Water Foundation, the team considered both GHG emissions and carbon sequestration to calculate net GHG emissions for cow-calf farms grazing only rangeland under different grazing strategies, Park said. Unlike most published work that isolates the analyses of GHG emission and carbon sequestration, he said they used field-measured soil organic carbon data to estimate the carbon sequestrations for different grazing management systems. “Contrary to other publications claiming cow-calf farms are the most significant GHG emission source in the beef production link, our results show that cow-calf farms converting to multi-paddock grazing in the Southern Great Plains region are likely net carbon sinks,” Park said. “The continuous grazing was less effective in sequestering carbon.”….
The researchers did find overall GHG emissions are higher in the Southern Great Plains than the other regions, with almost 80 percent of those GHG emissions coming from ruminant digestion. “But this means there is great potential to reduce these GHG emissions by increasing grass quality and digestibility using multi-paddock grazing, which could reduce total GHG emissions by as much as 30 percent,” Wang said. Compared to continuous grazing, multi-paddock grazing can improve grass quality as well as grass production, according to ongoing research on this subject. Teague has studied three grazing management alternatives on neighboring commercial ranches in three proximate counties in north Texas tall grass prairie: continuous grazing with light stocking, representing the best-case scenario for continuous grazing; traditional heavily stocked, continuous grazing, representing the most commonly used grazing management; and adaptive multi-paddock grazing, representing best-case rotational grazing. “Under multi-paddock grazing management, one paddock is grazed at a time while the other paddocks recover,” Teague said. “This grazing strategy uses short periods of grazing, long recovery periods, and adaptively changing recovery periods and other management elements as conditions change.”