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Soil Carbon

Submitted by bthoole on Thu, 12/06/2018 - 19:06

The way that the soil is treated determines the ability it has to affect the cycle carbon. Carbon naturally cycles in and out of the soil, which is why agricultural lands are considered to be one of the major sinks of carbon. With that, comes the responsibility to suitably manage the land to improve the carbon sequestration and reduce any emissions that come from the land. However, agriculture is currently the third largest source of anthropogenic greenhouse gases that are released. To better understand how the land can be better managed for sequestration, it is necessary to understand how it currently managed to result in these large emissions. One of the largest culprits is the practice of liming soils, with the IPCC estimating that nearly 100% of the carbon stored in soils that are treated with lime is released as carbon dioxide. Lime and other fertilizers are applied to these soils to better crop production by changing the pH of the soil or providing necessary elemental nutrients like calcium or phosphorous that are commonly deficient in acidic soils. Often, limestone and dolomite are used as the sources of lime, which as discussed above also release carbon dioxide as they are broken and crushed. It has no been investigated whether this crushing could be coupled with a carbon capture technique, but studies have been done on how liming affects the release of carbon dioxide in soils treated with phosphate solubilizing bacteria and other phosphorous sources.