Author
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Norton, Lloyd |
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Submitted to: Coal Ash Association Symposium Proceedings
Publication Type: Proceedings Publication Acceptance Date: 5/1/2007 Publication Date: 5/1/2007 Citation: Norton, L.D. 2007. Agricultural applications of FGD gypsum in soil and water management. In: Proceedings of the World of Coal Ash Congress, May 7-10, 2007, Covington, KY. 2007 CDROM. Interpretive Summary: Technical Abstract: Gypsum is a naturally occuring mineral that has unique properties and many uses. The purity of natural deposits vary widely due to the nature of the deposional processes. Flue gas desulfurization (FGD) gypsum is generally of a higher purity and has a consistent fine particle size making it a prefered material where available for agricultural applications. We conducted a number of studies using FGD gypsum as an electrolyte source for preventing clay dispersion and surface sealing of agricultural soils. This approach was very effective for improving rain water infiltration and reducing erosion. As a side effect, we found that when surface applying FGD gypsum to no-till fields crop yields have been increased through a combination of improved soil and water mangement and additon of soluble Ca and S fertility. Anticdotal evidence from farmers also indicates that soil drainage by tile has been improved by application of FGD gypsum which also positively affects crop yields. FGD gypsum has also been shown by other researchers to be very effective at reducing subsoil acidity by replacing exhangeable Al. The soluble Ca in FGD gypsum also replaces Na and Mg on soil clays making them less dispersive to low electolyte rainwater. This soluble Ca also will complex with soluble reactive phosphate (SRP) and reduce its concentration in runoff and its adverse affect on off-site water quality. |
