Gray Luvisols are polygenetic

Abstract

With respect to the pedosphere, human activities in the last 100 years have been the major driver of soil change. Despite human activities being one of the main soil forming factors recognized by soil scientists (in addition to climate, organisms, parent material, relief, groundwater, and time), the Canadian System of Soil Classification emphasizes soil as a natural body. We argue human-agricultural activities are direct and indirect drivers of significant changes to the carbon balance and cycling in A horizons of Gray Luvisolic soils in western Canada, resulting in changes to A horizon carbon stocks, structure, and micromorphology. Evidence from scientific literature, in-field soil profile observations and the National Pedon Database are presented in support of our argument. We propose a polygenetic, two-stage model of Gray Luvisol soil formation. The first stage is dominated by the climate forcing of the Holocene, resulting in a relatively stable boreal forest ecosystem including relatively minor perturbations from natural and human-induced wildfire and other disturbances. The second stage is dominated by direct, human-driven disturbances such as cultivation, release of exotic fauna (earthworms), and indirect human-driven disturbances associated with anthropogenic climate change. Further, we propose modest amendments to the Canadian System of Soil Classification to reflect a polygenetic model of soil genesis in Gray Luvisolic soils that preserve the balance between observation and interpretation inherent in the system.

Evaluating the Efficacy of Phosphogypsum as a Soil Amendment for Enhancing Fertility in Compacted Gray-Earth Soils of Kazakhstan During Comprehensive Land Reclamation

“…From a different point of view, this issue was considered by Dyck et al [26] who studied the process of increasing the fertility of gray earth soil in the context of its reclamation. In this case, it was based on an approach that consisted in using phosphogypsum to clean the soil of contamination.…”

Advances in soil survey and classification in Canada

“…These proposals, albeit generally straightforward, have a cascading effect on the keys to soil classification since any new taxon will need to be integrated into the existing taxonomic system. Two manuscripts target the Luvisolic Order (Dyck et al 2023;Pennock and Fisher 2022). Pennock and Fisher (2022) challenge the concept that the diagnostic horizon of a Luvisolic soil, the Bt horizon, is purely the result of lessivage, and examine development of a Bt horizon because of a lithological discontinuity.…”

“…Pennock and Fisher (2022) challenge the concept that the diagnostic horizon of a Luvisolic soil, the Bt horizon, is purely the result of lessivage, and examine development of a Bt horizon because of a lithological discontinuity. Dyck et al (2023) propose a polygenetic pathway for development of Gray Luvisols, with emphasis on the intergrade soils between the Luvisolic and Chernozemic that are so common in the Aspen Parkland, the nexus between the Great Plains and the Boreal. Miller et al (2022) revisit the use of the LFH horizon in nonforested soils; a timely contribution given the importance of accounting for accumulations of organic matter and soil carbon stocks in no-till agricultural systems where surface litter layers have long been ignored in soil profile descriptions.…”