Identification of humic substances on the transformation of an organic substrate

Abstract

The organic matter of the soil and humus are heterogeneous in composition. That is why the nature of soil organic matter has not yet been fully understood and causes many discussions. The purpose of this work is to study the identification features of humus in the process of peat's transformation. The results of a five-year experiment studying the processes of organic matter transformation in organic-mineral substrate based on peat growing coniferous seedlings in greenhouses are presented. In the dynamics of the group and fractional composition of humus for several years the biochemical essence of the humification process is revealed. To extract specific humic substances from the organogenic substrate, we used the method of fractioning humus into groups and fractions, which is a stepwise sequential extraction using solutions of sodium hydroxide and sulfuric acid. It was found that the organic matter of the substrate passes through three stages of transformation: hydrolysis of organic products → initial transformation → humification of lignin structures. There is a significant change in the ratio of the three main groups of humus in favor of humic acids at the third stage. In general, the system is tends to its most stable state: aromatic structures are copolymerized, the core of humic substances is densified, and humus gradually "matures".

Keywords

• Fulvic acid
• humic acid
• humus formation
• peat

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