|Kimble, J - USDA-NRCS|
|Reeves Iii, James|
|Yost, R - UNIV. OF HAWAII|
Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: December 20, 2002
Publication Date: N/A
Technical Abstract: As new field projects are considered for developing management practices that sequester carbon dioxide as soil C, a need exists for methods that accurately measure soil C. Various indirect methods have been recommended for measuring soil C, but additional evaluation is required if these methods are going to be used in long term monitoring. In developing countries, infrastructure limitations further restrict analytical options for within-country soil C monitoring. Indirect methods for measuring soil C such as dichromate oxidation, loss-on-ignition (LOI), diffuse reflectance infrared spectroscopy hold advantages in being simple and/or rapid but ultimately they need to be compared to the accepted standard of direct elemental analysis by combustion. A set of diverse soils (1.2 - 7.7 g C/kg soil) collected from the country of Mali in West Africa were analyzed by indirect soil C measurement and compared to C by combustion. Results showed that both dichromate oxidation and LOI were inaccurate for C determination. In contrast, accurate calibrations for soil C were developed using infrared spectroscopy indicating that this approach holds promise as a technology for rapid soil C monitoring.