Electrical charges play a role in the dust-lifting and deposition processes in cultivated peatlands

Abstract

Organic soils are often used to cultivate high-value field vegetables because of their high organic matter content and fertility. However, these productive soils are subject to many degradation processes that jeopardize their sustainability. In southern Quebec, wind erosion alone has been shown to provoke losses of peat depth ranging from 1 to 4 cm every year. Organic soils are known to be very erodible when compared to mineral soils, partly due to their low density and lack of structure. Understanding the physical erosive mechanisms is important as the degradation of cultivated histosols is a major concern worldwide. The physical mechanisms of wind erosion are well documented in general, with saltation, creep and suspension being the main processes. Yet, recent field works over cultivated peatlands in southern Quebec revealed the presence of high concentrations of aerosols above the surface even under quiescent wind conditions. Since the traditional wind erosion models could not explain this phenomenon, this study aims to explore potential explanations of such observations. The role of electrical charges was considered in this paper as a potential dust-lifting force. We introduce a series of laboratory experiments performed on organic soil samples that revealed a significant increase in suspended organic soil particles (i.e., soil losses) through the presence of electrical charges. This could explain the presence of aerosols observed above organic soil fields, which highlights the necessity to further investigate the role of electrical charges in wind erosion processes of organic soils.