“The Changing Model of Soil” Revisited

Abstract

In 1961, the late Marlin G. Cline wrote a remarkable essay entitled, “The Changing Model of Soil” for the 25th Anniversary Issue of the Soil Science Society of America Proceedings. Cline was most impressed with how geomorphology was enriching pedology, and with the increasingly sophisticated views of soil time and of the processes of soil formation. We revisit Cline's general objectives by re‐evaluating the changing model of soil from the perspective of the early 21st century, and by taking stock of the application of soil models to contemporary needs and challenges. Today, three ongoing changes in the genetic model of soil have far‐reaching consequences for the future of soil science: (i) that soil is being transformed globally from natural to human‐natural body, (ii) that the lower boundary of soil is much deeper than the solum historically confined to O to B horizons, and (iii) that most soils are a kind of pedogenic paleosol, archival products of soil‐forming processes that have ranged widely over the life of most soils. Together and each in their own way, these three changes in the model of soil impact directly human–soil relations and give structure and guidance to the science of anthropedology. In other words, human forcings represent a global wave of soil polygenesis altering fluxes of matter and energy and transforming the thermodynamics of soils as potentially very deep systems. Anthropedogenesis needs much better quantification to evaluate the future of soil and the wider environment.

Ideas and perspectives: Strengthening the biogeosciences in environmental research networks

“…fluxdata.org/partner-networks/long-term-soil-experiments/, last access: 2 August 2018), there are many hundreds of long-term agricultural research sites worldwide that are monitoring the sustainability of agricultural production over decadal timescales (Richter and Yaalon, 2012). These experiments study effects of tillage practices, rotations, and long-term amendments of fertilizers and organic materials such as manures and sludges on soils, microbial communities, biochemical and physical fluxes (such as those affecting soil water and heat regimes), and crop productivity.…”

The Effect of Harvest on Forest Soil Carbon: A Meta-Analysis

“…Nave et al [9] reported a mixed response to harvest in deeper soil (20-100 cm depth), ranging from a slight average decrease (−5%) in studies that reported C pools to a large average increase (+20%) in studies that reported only C concentration. Several recent reviews have highlighted the need for greater sampling of deep soil [26][27][28], especially as the shifting paradigm of SOM research has come to reject the assumption that deep soil C cannot not change on timescales relevant to anthropogenic C emissions [29][30][31]. Resolving the response of deep soil horizons to harvesting is important because these horizons occupy a much greater volume than surface O and A horizons.…”

Conservation opportunities across the world's anthromes

“…Brum et al (2013) found that an anthrome category (village) was a better predictor of the distribution of threatened amphibians than climate. The anthromes framework has also been suggested as a resource for conserving tropical forest biodiversity (Gardner et al, 2009), guiding management of sustainable agricultural systems (Richter & Yaalon, 2012) and identifying the relationships between multiple ecosystem services across heterogeneous land uses (Bennett et al, 2009).…”