ABSTRACT
This chapter describes major elements of the global balance of greenhouse gases, the influence of agriculture on this balance, and technical and economic factors that will influence agriculture’s impact of the Carbon (C) balance in the United States. The projections are, however, much less favorable if we consider the C released to the atmosphere by the energy needed for producing fertilizer and other means of production if this energy is produced through burning fossil fuels. In the late 19th and early 20th centuries, the settlement of North America was a major source of Carbon Dioxide, but this source is dwarfed by the effects of modern deforestation in Latin America and tropical Africa. In 1991 the US Environmental Protection Agency sponsored an assessment of alternative management practices and policies affecting soil C in agroecosystems of the central United States. Changes in agricultural management practices can induce dramatic changes in soil organic C.
