Work

Stability of organic matter in forest soils of the middle Central Atlas: Extraction by biochemical fractionation

Year: 2023

Type: article

Abstract: Organic matter is essential in forest ecosystems to maintain the structural stability of the soil. Following soil assimilation, it evolves in two opposite ways: mineralization and humification. This leads to the formation of a wide variety of substances that, evolve according to very different kinetics. This work involved studying the stability of organic matter in the soils of forest ecosystems: Atlas cedar, holm oak, zeen oak, and maritime pine. This study was performed on representative samples of the upper soil layer (0-30 cm) of the different ecosystems, using a biochemical fractionation technique. Results from the extraction of humic substances showed that humin is the main component (53 and 75%), followed by humic acids (19 and 34%) and fulvic acids (6 and 16%). These findings indicate stable carbon abundance and good sequestration of this element in the soils studied. Zeen oak and maritime pine have the most stable soil organic matter with a humification ratio of 4.30 and 4.10, respectively. Furthermore, the formation of humic substances is closely linked to the presence of clay that favors the formation of the clay-humic complex, making this material difficult to access by microorganism soils and therefore more resistant to decomposition. Ultimately, the studied soils have a stable organic matter which increases the dwell time of carbon in the soil. Such a result can be proved in further research, by using appropriate techniques like stable isotopes (13C).

Source: Soil Science Annual

DOI: 10.37501/soilsa/169154