Solonetzic soils of Canada: Genesis, distribution, and classification

Abstract

Miller, J. J. and Brierley, J. A. 2011. Solonetzic soils of Canada: Genesis, distribution, and classification. Can. J. Soil Sci. 91: 889–902. Soils of the Solonetzic order are defined as having a Solonetzic B horizon designated as a Bn or Bnt horizon. The Solonetzic Order includes four great groups: Solonetz, Solodized Solonetz, Solod, and Vertic Solonetz. Solonetzic soils are thought to develop via the stepwise pedogenic processes of salinization, solonization (desalinzation and alkalization), and solodization. Soluble salts are brought into the soil pedon of Solonetzic soils by capillary movement and evaporation from spring to fall, and upward water flow from the water table to the freezing zone in the winter deposits salts upon freezing. Solonization proceeds when desalinization lowers the total salt content and alkalization is initiated by high exchangeable Na. Solodization occurs when anisotropic flow conditions or a change in vertical hydraulic gradients prevent capillary rise and replenishment of soluble Na in the Bn horizon. Two common Solonetzic catenas are found in the prairies. In the first sequence, Gleyed Solonetz or Solonetz occur in the depressional areas of the landscape, and soils then grade through Solodized Solonetz, Solods, and in some cases, Chernozems or normal zonal soils at higher elevations. In the second sequence, Solods are found in the lowest topographic position, while Solodized Solonetz, Solonetz and Chernozems are found at progressively higher slope positions. Solonetzic soils have unique properties that adversely affect their use for agriculture and other land uses (e.g., construction, septic systems). Further interdisciplinary research is required to better understand the genesis of these soils at the “meter scale” or local landscape level because of the extreme spatial variability of these soils.