CalCAN has released a new fact sheet outlining the potential role of organic agriculture in climate protection.
Organic farming systems use soil management practices that offer the best opportunities to reduce GHG emissions, build soil organic carbon (SOC) and sequester atmospheric carbon. Among the most promising are: reduction/elimination of synthetic nitrogen fertilizer applications; use of organic fertilizers and cover crops; and, conservation tillage. A 2008 study funded by the California Energy Commission found that these practices are particularly effective when used in combination.
In addition, organic practices reduce the reliance on fossil fuel based inputs, and organic and pasture-based livestock management practices minimize methane emissions and have the potential for increasing soil carbon sequestration.
The following is a summary of some of the data on carbon sequestration potential of organic farming:
• In a twelve-year California study of organic farming practices, carbon sequestration was improved by 36 percent with the use of green manures and animal manures even though tillage was increased compared to conventional systems.
• An eight-year California study found that SOC increased 19 percent in organic and low input systems, as compared with 10 percent in conventional soils with synthetic fertilizers.
• After 23 years, organic management practices increased soil carbon by 15 to 28 percent and increased soil nitrogen by 8 to 15 percent.
• A nine-year USDA study found that organic production sequestered more carbon than no-till systems at all soil depths up to 30 cm.
• Studies comparing the energy inputs required for different livestock management systems suggest that conventional feedlot livestock require twice as much fossil fuel energy compared to grass-fed livestock due in large part to the use of synthetic fertilizers and pesticides used to produce the feed crops.