Science et changements planétaires / Sécheresse


Rôle de l’eau sur les propriétés physiques des sols Volume 5, issue 3, Septembre 1994

INRA, Science du Sol 78026 Versailles
  • Page(s) : 143-50
  • Published in: 1994

In normally-drained soils, the water filling pore spaces acts as a particle-binding agent and regulates the soil’s physical stability. Water allows for a certain longevity in the three-dimensional structures or discontinuities which arise from mechanical or biological action (e.g. cracks caused by abiotic phenomena, root channels by living organisms, etc.). After a drought or during a period of water-logging, the water may no longer have a cohesive effect on the particles. This may greatly enhance the soil’s susceptibility to surface erosion or compaction of the lower horizons. The various stresses applied to the soil through time (drying, consolidation pressure, etc.) partly determine long-term particle assemblages and hence the actual organisation of the soil structure. In freshly or in intensively cultivated soils, farming practices associated with high production levels can induce long-term changes to the soil’s physical properties and conditions of bioactivity. The consequences have still not been fully assessed, but could, in time, endanger soil fertility.