Prevention of subsoil compaction: technologies and strategic planning

TY - ABST

T1 - Prevention of subsoil compaction:

T2 - Advances and Innovations in Agricultural Engineering.

AU - Lamandé, Mathieu

PY - 2022

Y1 - 2022

N2 - Soil compaction is defined as the densification and the distorsion of soil by which total and air-filled porosity are reduced. This caused deterioration or even loss of one or more soil functions. Soil compaction reduces root growth, soil aeration, water drainage and filtering, and activity of macro- and microorganism. Therefore, soil compaction reduces crop yields and constricts time windows to perform optimal agricultural operations. The density of the topsoil (the soil above the tillage depth) will always be affected by traffic. However, natural processes (wetting-drying, freeze-thaw, soil biota) and tillage will be able to mitigate topsoil compaction rather quickly. In contrast, results reported by a range of studies indicate that compaction damages to the subsoil (soil beneath the tillage depth) are lasting for decades and might therefore be considered as permanent. Mechanical loosening of the subsoil is a very problematic solution: efficient subsoiling has to be performed when the soil is friable to avoid smearing, and as the soil is weaker after fragmentation severe recompaction will take place when re-trafficked.The persistence of the effects of subsoil compaction advocates for efforts toward prevention of this process, and not only limitations of the volume of compacted subsoil.Soil compaction takes place during field traffic when the mechanical stresses from machinery exceed soil mechanical strength. It means that soil compaction can be prevented if the mechanical stresses transmitted to the subsoil are kept beneath soil mechanical strength. Therefore, risk assessment should be based on a comparison of the stress applied to the subsoil and its strength. The most up-to-date decision support tool for risk assessment of subsoil compaction, Terranimo, is freely available for farmers, contractors and extension services. Farmers are generally concerned about the state of their soil and are willing to engage in sustainable soil management. However, the use of Terranimo® in its current online form by farmers to plan field operations is still limited. Technologies that could help to minimize the risk of soil compaction exist already: wide tyres able to carry high loads with low inflation pressure, central tyre inflation systems, tracks, offset steering machinery to reduce repeated wheeling, GPS steering to reduce trafficked area. Despite these highly relevant technological advances, soil compaction problems have aggravated during recent years and decades. Subsoil compaction is invisible to farmers and often immediate concerns such as fulfilling delivery contracts, economic considerations, access to labour and time, are prioritized over long-term concerns such as prevention of soil compaction. Furthermore, although farmers are an important decision-maker in relation to subsoil compaction, a range of other actors influence farming practice, including machinery manufacturers, external contractors and political regulation of other management practices. The aim of this presentation is to present and discuss the opportunities and barriers of using the available technical solutions to prevent subsoil compaction.

AB - Soil compaction is defined as the densification and the distorsion of soil by which total and air-filled porosity are reduced. This caused deterioration or even loss of one or more soil functions. Soil compaction reduces root growth, soil aeration, water drainage and filtering, and activity of macro- and microorganism. Therefore, soil compaction reduces crop yields and constricts time windows to perform optimal agricultural operations. The density of the topsoil (the soil above the tillage depth) will always be affected by traffic. However, natural processes (wetting-drying, freeze-thaw, soil biota) and tillage will be able to mitigate topsoil compaction rather quickly. In contrast, results reported by a range of studies indicate that compaction damages to the subsoil (soil beneath the tillage depth) are lasting for decades and might therefore be considered as permanent. Mechanical loosening of the subsoil is a very problematic solution: efficient subsoiling has to be performed when the soil is friable to avoid smearing, and as the soil is weaker after fragmentation severe recompaction will take place when re-trafficked.The persistence of the effects of subsoil compaction advocates for efforts toward prevention of this process, and not only limitations of the volume of compacted subsoil.Soil compaction takes place during field traffic when the mechanical stresses from machinery exceed soil mechanical strength. It means that soil compaction can be prevented if the mechanical stresses transmitted to the subsoil are kept beneath soil mechanical strength. Therefore, risk assessment should be based on a comparison of the stress applied to the subsoil and its strength. The most up-to-date decision support tool for risk assessment of subsoil compaction, Terranimo, is freely available for farmers, contractors and extension services. Farmers are generally concerned about the state of their soil and are willing to engage in sustainable soil management. However, the use of Terranimo® in its current online form by farmers to plan field operations is still limited. Technologies that could help to minimize the risk of soil compaction exist already: wide tyres able to carry high loads with low inflation pressure, central tyre inflation systems, tracks, offset steering machinery to reduce repeated wheeling, GPS steering to reduce trafficked area. Despite these highly relevant technological advances, soil compaction problems have aggravated during recent years and decades. Subsoil compaction is invisible to farmers and often immediate concerns such as fulfilling delivery contracts, economic considerations, access to labour and time, are prioritized over long-term concerns such as prevention of soil compaction. Furthermore, although farmers are an important decision-maker in relation to subsoil compaction, a range of other actors influence farming practice, including machinery manufacturers, external contractors and political regulation of other management practices. The aim of this presentation is to present and discuss the opportunities and barriers of using the available technical solutions to prevent subsoil compaction.

M3 - Conference abstract for conference

SP - 34

EP - 34

Y2 - 29 November 2022 through 30 November 2022

ER -