Subsoiling

Deep, non-inversion loosening below plough depth using narrow or winged tines to fracture compacted layers that restrict infiltration and rooting. Applied selectively where a pan or dense subsoil is diagnosed, and timed when the target layer is dry enough to shatter. Fracturing restores vertical macropores, increases infiltration, and can reduce overland flow and erosion; it also enables deeper root water uptake. Effects may be short-lived if traffic or later tillage re-compacts, so it is best paired with controlled traffic, residue retention, and deep-rooted covers; on drained fields it should connect fissures to permeable backfill. Typical working depths are about 30-50 cm in arable soils, with sward-lifting variants in grassland. Within a “sponge” strategy it works as an enabling, infrequent corrective that re-opens a clogged layer so biological and structural measures can then maintain the gains.