Harmon, Mark E.; Lajtha, Kate. 1999. Analysis of detritus and organic horizons for mineral and organic constituents. In: Robertson, G. Philip; Coleman, David C.; Bledsoe, Caroline S.; Sollins, Phillip, eds. Standard soil methods for long-term ecological research. New York, NY: Oxford University Press: 143-165.
The analysis of the chemical composition of plant matter (leaves, stems,roots, and detritus) is critical for studies of nutrient turnover in ecosystems and of the biotic pools of important biogeochemical elements, as well as for understanding nutrient and chemical limits to plant growth. Understanding the organic constituents of plant litter and their transformation into those forming soil organic matter is also a critical need given their link to the biogeochemistry of other elements and the storage of carbon in ecosystems.
The chemical analysis of plant materials for mineral constituents is fairly straightforward, although different materials may need either different pretreatment or slightly different digestion methods. In contrast, the analysis of organic constituents is not straightforward because of both the underlying complexity of the compounds themselves and the variety of methods that can be used, none of which are perfect. Our intent in this chapter is to review these methods and recommend standard protocols. In the case of organic constituents, we recognize that these recommendations may become dated rapidly if the most modern instrumentation becomes generally available.