Relation of Organic Matter to Organic Carbon in the Peat Soils of New York¹

Abstract

The organic matter of soils is often determined quantitatively by multiplying the percentage of organic carbon in the soil by the Van Bemmelen factor 1.724. In using the factor it is assumed that the organic matter of the soil contains 58% of carbon.A critical study of the methods for the qualitative determination of soil organic matter lead Waksman and Stevens 3 to conclude that the method mentioned in the preceding paragraph is the most reliable of those now available. In a recent paper, Lunt 4 reports that the factor 1.7.24 is too low to be applicable to the organic horizons of forest soils. They were found to contain less than 58% of organic carbon, and he suggests a conversion factor of r.86 when the amount of organic matter in such soils is to be computed from the percentage of organic carbon which they contain. He refers to the results of other investigators who found the value 1.724 to be too low to estimate satisfactorily the amount of organic matter of peat soils.The literature dealing with the methods for the determination of soil organic matter is reviewed in the two papers which are cited and a repetition is unnecessary at this time. It reveals little information regarding the expediency of using the factor 1.724 in calculating the organic matter content of peat soils from the percentage of organic carbon.At this laboratory a study of the chemical composition of the peat soils of New York is in progress. As a result of the work data are available which will throw some light on whether the conventional factor for converting organic carbon to organic matter is too low to be applied to peat soils. The purpose of the present paper is to report the organic carbon and the organic matter content of a number of peat soils and to record the factor which was obtained for each soil when its content of organic matter was divided by its content of organic carbon.

Vegetation, substrate and hydrology in floating marshes in the Mississippi river delta plain wetlands, USA

“…Floating mats, in particular, are almost entirely organic. Organic carbon density averages 0.026 g cm -3 in Louisiana marsh soils , equivalent to 0.045 g cm -3 of organic material [using a conversion factor of 1.724 for carbon to organic matter (Wilson & Staker 1932)]. This density is within the range of substrate bulk densities we measured for floating marshes, confirming a near- ly pure organic substrate.…”

Sedimentation, accretion, and subsidence in marshes of Barataria Basin, Louisiana1

“…to a depth of 38 cm were analyzed by dry combus- tion. Organic matter content was calculated from the organic carbon value determined by dry combustion in a carbon train, using the multiplier of 1.724 derived by Wilson and Staker (1932).…”