from conclusion: "In agriculture, C sequestration research has tended to focus primarily on productive cropping systems. Too few experiments have specifically addressed best management practices for improving soil C storage, and fewer yet evaluate practices to reduce emissions of non-CO2 trace gases. Research needs to be expanded to less well-defined components of US agriculture. Despite occupying 37% of total US land area, relatively little research has evaluated how different management practices may affect C sequestration in US rangelands and pasture lands. Even less is known about the management potential for mitigating GHG emissions in the US horticulture industry and for turfgrass. Organic soils and wetlands present especially complex management challenges since they involve significant emissions of more than one GHG, and practices that reduce emissions of one GHG may stimulate another. Agroforestry contributions to GHG mitigation have not been considered in national inventories. Addressing these research needs, including the challenges presented by biofuels development and climate change feedbacks on agricultural GHG emissions, will be critical for giving US agriculture the necessary tools to mitigate climate change. Continued progress on scaling and monitoring methodologies will be essential to implement regional/national analyses and assessments that climate change policies and protocols will demand."
