National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Land and Environment, Shenyang Agricultural University
Supported by the National Natural Science Foundation of China (Nos. 41977088 and 41807089)
As the basic unit of soil structure, soil aggregates play an important role in the soil and are vital for maintaining soil ecological functions (such as carbon sequestration and nutrient retention, etc.). The formation and stability of aggregates are based on the complex interactions between minerals, organic matter and organisms in the soil, but the mechanisms of these interactions still lack a systematic summary. This article reviews the research history of soil aggregates over the past century and sorts out the historical nodes for the proposition of key theories, including important theoretical viewpoints, main theoretical models (Monnier’s aggregate stability model, Tisdall and Oades’ aggregate hierarchy model, Six’s aggregate turnover model and Christensen’s tertiary structure model), indexes for evaluating the structure and stability of soil aggregates, comparison of two main sieving methods (dry and wet sieving), and classification basis and classification type for soil aggregates. Furthermore, it expounds on the action mechanism of aggregate basic structural units (minerals, organic matter, organisms and their derivatives) and the formation and stabilization mechanism of microaggregates and macroaggregates, detailing the aggregate formation by organo-mineral interactions (Wershaw’s bilayer model and Kleber’s zonal model) and biological control of aggregate turnover (Miller’s sticky string sag theory). Through this review, it is found that there are more in-depth discussions on the factors affecting the formation and stability of soil aggregates, but few studies have addressed the effects of pH and redox processes on the aggregates in the paddy and waterfront soil systems. Finally, the future development of soil aggregate research is highlighted, in expectation of providing theoretical reference for the sustainable use of soil resources.
LIU Yalong, WANG Ping, WANG Jingkuan. Formation and Stability Mechanism of Soil Aggregates: Progress and Prospect[J]. Acta Pedologica Sinica, DOI:10.11766/trxb202112180686,[In Press]