Reflections on the Nature of Soil and Its Biomantle

Abstract

Apart from the engineering approach to soil as movable regolith, most specialists who study soil view it as a plantlinked, land-only, and Earth-only entity whose character and properties are explained by a mix of four environmental factors-climate, organisms, relief, and parent material-that operate over time. These factors function to produce soil, where S 5 f (cl, o, r, p, t . . .). This relationship constitutes the five-factors, ''clorpt,'' explanatory model of soil formation that lends itself to the survey, classification, and mapping of soil for agricultural and environmental purposes and aids in soil valuations and soil conservation-management needs. In geomorphology and Quaternary research, it has met success in soil chronosequence and age-dating studies. But inasmuch as soil is the most complex and unparsimonious of all natural science entities, is any model so conceptually endowed that it allows a deep understanding of the full range and nuances of soil-forming processes? Can a conventional model provide new visions and different levels of knowledge beyond conventional levels? We present a multifaceted and biodynamic approach that views soil in different ways. One is that soil is the outer integument, or ''skin'' of all lithic-composed celestial bodies, planets, their satellites, and such. But Earth differs from others because water covers nearly three-fourths of its surface and life covers nearly all of its surface and produces a biodynamically mediated ''epidermis''-a biomantle that other planets lack. The biomantle constitutes a subaerial-subaqueous continuum across the globe. Life imparts myriad biomechanical and biochemical processes-biodynamic processes-to the soil-biomantle continuum, and these coact with physical processes in producing soil landscapes. This multifaceted approach is embedded as a component of the dynamic denudation framework of landscape evolution, which carries useful and different explanatory and predictive powers for studying the global soil-biomantle that may be invisible, unacknowledged, or unstressed in other frameworks, including one where ''organisms'' essentially means plants. To appreciate how our approach differs from conventional views of soil formation, and to provide a historic context, we reflect on the nineteenth-and twentiethcentury turning points in Earth sciences, mainly in geography, geology, and soils, which led to the five-factors (clorpt) model as the sine qua non way to explain soils. The details of our approach then follow.

Humusica 1, article 2: Essential bases—Functional considerations

“…It simply says that vegetation or soil or the result of their co-evolution (the landscape) is dependent on climatic, biotic, topographic, initial state, and time factors: no mathematical formulas, no numbers, but graphic interpretations, like maps of soil and vegetation or points on a bi-plot considering two or three factors and showing a trend. The point raised by Johnson et al (2005) is that, in soil formation, by "biotic factor" Dokuchaev (and Jenny) intended a strong influence by plants, and this view might be opposed to that of Darwin for whom, on the contrary, animals [earthworms, in Darwin (1881)] are the biotic factor (named "vegetable mould" by Dokuchaev and Darwin) of soil formation. Johnson et al (2005) preferred the "animal" interpretation.…”

“…The point raised by Johnson et al (2005) is that, in soil formation, by "biotic factor" Dokuchaev (and Jenny) intended a strong influence by plants, and this view might be opposed to that of Darwin for whom, on the contrary, animals [earthworms, in Darwin (1881)] are the biotic factor (named "vegetable mould" by Dokuchaev and Darwin) of soil formation. Johnson et al (2005) preferred the "animal" interpretation. In this guide, we link specific humipedons to particular humus "systems", avoiding the distinction between plant, animal and/or microbial influences: all organisms are in play and their activities are tightly interconnected in this concept.…”

“…There are two instructive articles that resume the debate in question since about a century ago, when scientific minds believed that they were able to understand the relationships between plants, soils, and animals. We have come further, but the question is still unresolved: -Role of the plant factor in pedogenetic functions (Jenny, 1958) -Reflexions on the nature of soil and its biomantle (Johnson et al, 2005).…”

“…In the second article, Johnson et al (2005) oppose Darwin's animal-process (Darwin, 1881) and Dokuchaev's terrestrial five-factors (Dokuchaev, 1883), zonal approach.…”

Human-Soil Relations are Changing Rapidly: Proposals from SSSA's Cross-Divisional Soil Change Working Group

“…Excellent examples include ecosystem restoration (Craft et al, 2003) and soil amendments such as liming (Farina et al, 2000). In fact, if humanity is to improve environmental management in the coming few decades, we must manage a great diversity of soils much more positively (Buol et al, 2003;Schaetzl and Anderson, 2005;Johnson, 2005;Palm et al, 2007;Dominati et al, 2010).…”