Carbon Sequestration in Soils

Abstract

The production, transport, and application of N fertilizer incur COemissions to the atmosphere, which must be subtracted from any apparent increases in soil organic matter before calculating the net carbon sequestration in agricultural soils. Similarly, net carbon sequestration in arid-land soils is reduced by COis emissions when fossil fuels are used to pump irrigation water and when pedogenic carbonate precipitates in soils. Application of manure, important to maintaining agricultural tilth, does not offer a mechanism for the net sequestration of carbon in soils that is relevant to the Kyoto Protocol.