According to Article 3.4 of the Kyoto Protocol, agricultural soil could be used as a sink for carbon sequestration and hence it may provide an alternative venue to sequester the greenhouse gas emission. US plans to reduce the carbon emission amount by seven percent below the 1990 level within the target date of 2008-2012. The major approaches to achieve the goal targeted by Kyoto Protocol in US are through fossil fuel tax and increasing forest area by afforestation. This means fossil fuel price will increase which will have a direct impact to conventional tillage cost. As a result farmers would be motivated to use less machinery operation in farming and hence may use conservation tillage in farming practices. Rather than cause and effect relationship created by fuel price increase, conservation tillage itself has been considered as a method suggested to increase carbon sequestration. We analyze the economic and environmental roles of conservation tillage in carbon sequestration. The use of conservation tillage helps to sequester carbon in the form of soil organic matter. We examined the potential of conservation tillage in sequestering carbon and its role in increasing soil natural capital and thus the productivity of soil. We then used the concept of production efficiency to calculate the benefits of soil carbon sequestration using sustainability criteria. The detail of carbon sequestration and soil natural capital buildup were demonstrated using conservation tillage practiced in cotton production in Georgia. Four systems of conservation tillage encompassing both chemical and organic source of plant nutrients were compared for their capacity to sequester carbon. Organic matter buildups were faster in a system with conservation tillage and organic sources of nutrient compared to conventional tillage. Result indicated that in a system with a slow buildup of natural capital, production efficiency was not significant. This has resulted the system to be unprofitable in the short run and unsustainable in the long run. The system with a high amount of organic matter increases the production efficiency of applied inputs and also plays an important role in substituting chemical fertilizers. Alternative tillage management systems were evaluated for their sustainability using total factor productivity. It was found that conservation tillage meets criteria of sustainability more often than the management system containing conventional tillage. Conservation tillage was found to be the best alternative not only to sequester carbon but also developing natural capital-based sustainable system.


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