Black Carbon and Its Effect on Carbon Sequestration in Soil

Marek Kopecký,Jana Batt,Ladislav Menšík,Radka Váchalová,Miroslav Dumbrovský,Petr Konvalina,Petr Mráz,Ladislav Kolář,Trong Nghia Hoang

doi:10.3390/agronomy11112261

Abstract

The properties of black carbon (BC) are described very differently in the literature, even when determined by the same methodological procedure. To clarify this discrepancy, BC was investigated in the clay Cambisols of southern Bohemia, Czech Republic, in groups of soils with lower and higher deposition of its atmospheric fallout. The BC determination was performed according to a modified method of Kuhlbusch and Crutzen (1995). The amount of the free light fraction, the occluded light fraction of soil organic matter and its ratio, the amount of heavy soil fraction DF, and its soil organic matter DFOM were determined. Other soil characteristics were identified. It was found that there are two very different types of BC in soils. Historical BC from biomass fires, and new, anthropogenic, from the furnace and transport fumes. Historical BC has a significant effect on the organic matter of the heavy soil fraction, on the ratio of the free and occluded soil organic matter fraction, and the number of water-resistant soil aggregates. Anthropogenic BC does not have this effect. Because this form of BC is not significantly stabilized by the colloidal mineral fraction, it is necessary to take general data on BC’s high stability and resistance to mineralization in the soil with circumspection.

Highlights

Over the last 150 years, there has been a decrease in organic carbon (Corg) in the world’s soils [1] and a consequent increase in atmospheric CO2 [2]
It is evident from the relationship of its content in the soil to the heavy fraction of soil organic matter; from the ratio of free light fraction and the occluded light fraction of soil organic matter
In soils from localities loaded by atmospheric fallout, the relationship of black carbon content to these parameters is negligible

Summary

Introduction

Over the last 150 years, there has been a decrease in organic carbon (Corg) in the world’s soils [1] and a consequent increase in atmospheric CO2 [2]. Carbon sequestration in stable and resistant fractions of soil organic matter (SOM) in the soil is very current. The labile part is the primary source of energy for soil microorganisms and contributes to the nutrient regime of soils [5]. This applies in particular to the water-soluble part of SOM. Humic substances, humic acids, humins, and partially fulvic acids were considered stable forms of soil carbon. At present, this humification model is widely criticized, and the presumed stability of humic substances is questioned [7,8]. Criticism of this conception has emerged [9]

Methods

Results

Conclusion