Vulnerability of subsoils in Europe to compaction: a preliminary analysis

Abstract

Identifying the vulnerability of subsoils to compaction damage is an increasingly important issue both in the planning and execution of farming operations and in planning environmental protection measures. Ideally, subsoil vulnerability to compaction should be assessed by direct measurement of soil bearing capacity but currently no direct practical tests are available. Similarly, soil mechanics principles are not suitably far enough advanced to allow extrapolation of likely compaction damage from experimental sites to situations in general. This paper, therefore, proposes a simple classification system for subsoil vulnerability to compaction based for field use on local soil and wetness data at the time of critical trafficking, and, at European level, on related soil and climatic information. Soil data are readily available 'in Country' or from the European Soil Database and climatic data are stored in the agrometeorological database of the MARS Project. The vulnerability to compaction is assessed using a two-stage process. First, the inherent susceptibility of the soil to compaction is estimated on the basis of the relatively stable soil properties of texture and packing density. Second, the susceptibility class is then converted into a vulnerability class through consideration of the likely soil moisture status at the time of critical loadings. For use at local level, adjustments are suggested to take account of possible differences in the support strength of the topsoil and specific subsoil structural conditions. The vulnerability classes proposed are based on profile pit observations, on a wide range of soils examined mainly in intensively farmed areas where large-scale field equipment is employed. A map of soil susceptibility to compaction in Europe has been produced, as the first stage in developing a more rigorous quantitative approach to assessing overall vulnerability than has been possible hitherto.

Toward a tool aimed to quantify soil compaction risks at a regional scale: Application to Wallonia (Belgium)

“…Compaction causes a decrease in porosity and an increase in soil strength that may restrict root growth and affect the density and diversity of soil mesofauna and bacterial communities (Soane and van Ouwerkerke, 1995;Batey and McKenzie, 2006;Frey et al, 2009, Lipiec et al, 2012. Soil compaction not only reduces crop and forest production, but has also negative environmental effects (Jones et al, 2003). Indeed, saturated hydraulic conductivity is reduced, increasing the risk of runoff of water and pollutants towards surface waters, and the movement of nitrate and pesticides into ground waters.…”

“…Considering the detrimental effects of soil compaction, the proposal of the EU Commission for a Soil Framework Directive mentions soil compaction as one of the major threats to a sustained quality of soils in Europe (COM, 2006). The compaction of the subsoil, defined as 'subsurface soil material that lies below the normal cultivation depth or pedological A horizon', is particularly problematic since it is difficult and expensive to alleviate (Hakansson and Reeder, 1994;Spoor et al, 2003). Subsoil compaction risks are increasing with growth in farm size, increased mechanisation and equipment size, and the drive for greater productivity (Jones et al, 2003).…”

“…The compaction of the subsoil, defined as 'subsurface soil material that lies below the normal cultivation depth or pedological A horizon', is particularly problematic since it is difficult and expensive to alleviate (Hakansson and Reeder, 1994;Spoor et al, 2003). Subsoil compaction risks are increasing with growth in farm size, increased mechanisation and equipment size, and the drive for greater productivity (Jones et al, 2003). In analysing soil compaction, a distinction has to be made between the susceptibility of soils to compaction and their vulnerability.…”

“…The soil's vulnerability to a given threat is determined taking into account the inherent soil susceptibility and an exposure estimate based on an evaluation of the stresses inflicted by land management and climate (Troldborg et al, 2013). Jones et al (2003) propose a simple classification system for subsoil vulnerability to compaction using a two-stage process. First, the inherent susceptibility of the soil to compaction is estimated on the basis of the relatively stable soil properties, such as soil texture, nature of clay, bulk density, organic matter content, structure, soil moisture content and soil moisture potential.…”

Structural sustainability of cambisol under different land use system

“…The precompression stress separates the region of recoverable deformation from the non-recoverable deformation and thereby defines the point where soil structure degradation may occur (Silva et al, 1999;Dias Junior & Pierce, 1996;Silva et al, 2007;Severiano et al, 2008;Ajayi et al, 2010;Severiano et al, 2010a,b;Araujo Junior et al, 2011;Pacheco & Cantalice, 2011;Figueiredo et al, 2011). It has been used as a parameter to evaluate the susceptibility and vulnerability of soil structure to compaction under varying management scenarios (Jones et al, 2003;Spoor et al, 2003;Arvidsson & Keller 2004;Ajayi et al, 2010). Since it has been established that soil structure degradation may occur at any moisture content (Dias Junior & Pierce, 1995), it is important that any study designed to monitor soil structural changes must measure soil properties that would highlight these deformations at various moisture level.…”