Traditions and innovations in soil humus doctrine
Authors:   Institute of Soil Science and Agrochemistry of the Siberian Branch of the Russian Academy of Sciences, Dergacheva M.I. 
Published: March 2022

The purpose of the work. This article does not claim to be a complete review of the problems currently existing in the Doctrine of Soil Humus and reflected in numerous publications, but aims to present the author's vision of a number of aspects related to the possibilities of combining traditions and innovation - one of the general scientific methodological techniques - in the development of this scientific direction. Methodology. The development and current state of two directions in the study of humus substances of soils – chemical and ecological - are considered. It is emphasized that within the framework of the chemical direction, the search for new (additional) techniques and methods is required to prove the specificity of the chemical structure of humus substances as an independent group of natural carbonaceous compounds. At this stage of research, the most promising may be the consideration of the mechanism of humus substances formation from the standpoint of supramolecular chemistry. The methodological basis for the interpretation of the research materials in the section devoted to the ecological direction is a systematic approach and theoretical provisions of soil ecology. It is proposed to preserve the traditional concepts of terms, including the term humus, when solving problems within the framework of the ecological direction, and to clarify the conceptual scope of some terms used in solving problems related to the mechanism of humus substances system formation, their chemical structure and properties as natural substances of a special specific class of chemical compounds within the framework of the chemical direction. In this article, when considering issues related to the understanding of the humus substances totality as a system, the terms humus and the system of humus substances are used as synonyms. Main results and conclusions. It is proposed to consider humus and humus substances from the standpoint of different directions identified in the Doctrine of Soil Humus. Within the framework of the chemical direction, this soil component can be considered as a substance and as a natural open system. In the first case, humus and humus substances are studied on the basis of a reductionist approach and are interpreted on the basis of the laws, principles, and rules of traditional chemical fields, including the chemistry of natural compounds and polymer chemistry. The emergence of facts, statements, conclusions (which have not yet lost their significance and can relate to traditional ones) is traced at different stages of the development of the Doctrine of soil humus from the origins to the present time. The paradigm of the 20th century, which has not yet been supplanted by other concepts and dominant in modern times, classifies humus substances with a stable structural organization as carbon compounds with a variable composition and is considered as traditional. Consideration of humus substances totality as a complex natural self-organizing and self-regulating system requires other approaches to the study and interpretation of the materials obtained, which are based on a systematic approach that determines the comparison of monofactorial soil series, in each of which the objects of research differ in only one condition, property, chemical structure or function. It is necessary to continue studying the effect of alkaline extraction on the state of humic acids by previously applied and new methods, using the widest possible variety of monofactorial soil series of various natural and anthropogenic conditions of formation, and when a critical level of materials accumulates, it will be possible to draw an unambiguous conclusion and determine those conditions under which alkaline extraction should be excluded.