Soil Drainage as an Active Agent of Recent Soil Evolution: A Review

Abstract

While research on pedogenesis mainly focuses on the long-term soil formation and most often neglects recent soil evolution in response to human practices or climate changes, this article reviews the impact of artificial subsurface drainage on soil evolution. Artificial drainage is considered as an example of the impact of recent changes in water fluxes on soil evolution over time scales of decades to a century. Results from various classical studies on artificial drainage including hydrological and environmental studies are reviewed and collated with rare studies dealing explicitly with soil morphology changes, in response to artificial drainage. We deduce that soil should react to the perturbations associated with subsurface drainage over time scales that do not exceed a few decades. Subsurface drainage decreases the intensity of erosion and must i) increase the intensity of the lixiviation and eluviation processes, ii) affect iron and manganese 2 dynamics, and iii) induce heterogeneities in soil evolution at the ten meter scale. Such recent soil evolutions can no longer be neglected as they are mostly irreversible and will probably have unknown, but expectable, feedbacks on crucial soil functions such as the sequestration of soil organic matter or the water available capacity.Keywords: cultivation, human-induced soil evolution, pedogenesis, soil processes, subsurface drainage.Soil evolves permanently under the impact of fluxes of matter and energy (Chadwick and Chorover, 2001). These fluxes change through time according to the main pedological factors defined by Jenny (1941Jenny ( , 1961, namely topography, climate, and biota, including man, who was early recognized as a factor affecting soil evolution through his impact on fluxes (Yaalon and Yaron, 1966). Recent changes in these fluxes, in response to either human practices or global climate change, have probably resulted in recent soil evolutions. Such recent soil evolutions over time scales of a few decades are, however, most often neglected by comparison to the long-term soil formation on millennial to multi-millennial time scales and are not very well known until now.Water fluxes are of particular concern as water is the weathering reactive agent as well as the transporting phase. Thus, changes in water fluxes affect chemical weathering and transport of solutes and particles through soils (Chadwick and Chorover, 2001;Lin et al., 2005). Changes in water fluxes due to practices such as irrigation or drainage must induce recent soil evolutions.Irrigation mainly increases the amount of water flowing through soils. Artificial subsurface drainage, designed to remove excess water from soils, not only reduces the residence time of water in soils and increases soil aeration inducing changes in its redox status, but also increases the amount of infiltrating water and induces changes in the water pathways by respectively reducing the runoff (Bengtson et al., 1995;Grazhdani et al., 1996) and intercepting water fluxes at regular 3 intervals. Thus, artificial d...

Atributos De Um Solo Florestal Em Uma Topossequência E Relações Com a Comunidade Arbórea

“…/ jun. 2016 Além dos aspectos relacionados à deposição de sedimentos, a concentração maior de nutrientes nas parcelas iniciais das transecções B e C pode ser resultado da drenagem deficiente observada nesses locais, que reduz as perdas de bases pelo processo de lixiviação e retarda a decomposição da matéria orgânica (MONTAGNE et al, 2009). Observa-se, na figura 2, a tendência apresentada pelos teores de P, K, Ca e Mg nas transecções B e C, demonstrando a existência de um gradiente edáfico, com redução nos teores de macronutrientes do solo à medida que as subunidades se afastam da zona de deposição de deflúvios e de drenagem deficiente.…”

Surface Runoff and Soil Physical Properties as Affected by Subsurface Drainage Improvement of a Heavy Clay Soil

“…The clear increase of subsurface drainflow immediately after the drainage improvement (Fig. 2) was mainly affected by the good permeability of the backfill material (gravel, topsoil/wood chips) of the drain trench allowing the water infiltrate and drain quickly from surface and topsoil to deeper layers as discussed in Turtola and Paajanen (1995) and Montagne et al (2009). We can also presume that the ploughing of the soil (normal to drain pipelines) enhanced the subsurface drainflow by increasing the temporal water storage capacity of wet soil during rainy and snow melting periods, and by conducting the topsoil layer runoff (in 0-20 cm) towards drain trench.…”

Do we need to include soil evolution module in models for prediction of future climate change?

“…These results are in good agreement with macroscopic observations. Montagne et al (2009) showed that by removing the excess of water, agricultural drainage induces two gradients of water fluxes and of redox conditions between the mid-drain position and the immediate vicinity of the drain. These gradients have not induced a marked soil differentiation between position 210 and position 400.…”