Field monitoring of wind erosion of organic soils in southwestern Quebec, Canada

Wind erosion threatens the organic soils used for agricultural production in the Montérégie region of southwestern Quebec, Canada. Despite estimated regional soil losses of 1 to 4 cm per year, little research globally has focused on wind erosion in soils with high organic matter content. In this study, wind erosion was monitored from July 2019 to October 2022 at two sites in the Montérégie region. This paper presents the results of an intensive effort to quantify soil losses and characterize windblown sediments trapped during multiple erosion events. The field monitoring suggests that organic soils are particularly vulnerable to erosion during the spring. The most severe erosion episode occurred in June 2020, during which major dust storms were recorded. Inter- and intra-annual variations in wind erosion were primarily driven by meteorological variables such as rainfall, relative humidity, and wind speed. Additionally, soil losses appeared to vary with the degree of soil decomposition. While wind-eroded material became finer with height, aggregates as large as 1.9 mm were still detected at 85 cm above the soil surface. Furthermore, aggregates with a mean diameter of 4 mm were transported by saltation up to a height of 25 cm. This suggests that, due to their lower density, the wind-erodible fraction of organic soils is greater than that of mineral soils. These findings demonstrate that wind erosion partly governs the subsidence of organic soils, even when wind events are sporadic. Farmers are thus advised to take measures to reduce soil exposure to mitigate wind erosion.