Problems and Limitations of the Dichromatometric Method for Measuring Soil Organic Matter Content: A Review
Е. В. Шамрикова, Е. В. Ванчикова, Б. М. Кондратенок, Е. М. Лаптева, S. N. Kostrova
Abstract
The content of soil organic matter (SOM) is a fundamental characteristic of the humus status of soils. The dichromatometric method based on a significant variety of measurement approaches is actively used in world practice to assess the SOM content. The unification of methods for determining the SOM content and other soil parameters is an international communication tool, which enables the interaction of specialists for the creation of databases on soils of the world and for inventory and monitoring of soil resources. The given data show that some modifications of Tyurin’s method may include procedures, which reduce the accuracy of the SOM measurement. The staff of the Institute of Biology has developed and certified a new modification of the method by Tyurin, excluding these procedures. The correctness of the introduction of a correction factor f = 1.15 into the calculation of the SOM content to account for incomplete oxidation of carbon of organic compounds has been experimentally determined. The f factor used in case, when the measurement error does exceed 20%, provides the results, which are consistent with the methods by Walkley-Black and high-temperature combustion of organic carbon on an analyzer.