Improvement of degraded soil physical conditions following the establishment of permanent pasture

Abstract

Conventional cultivation practices are known to degrade the physical properties of soils. The objective of this study was to measure changes in soil physical conditions following the establishment of permanent pasture (perennial ryegrass/white clover) on a structurally degraded soil. The physical regeneration of the topsoil was monitored over a 4-year period using a visual structure evaluation method as well as more widely used physical measurements of soil quality (e.g. soil bulk density, macroporosity, water infiltration rates, and earthworm numbers). Over the first four years of permanent pasture, there was a significant increase in macroporosity and decrease in soil bulk density from year one to year four following pasture establishment. Earthworm numbers increased from 120 m⁻² to between 440 and 620 m⁻², and water infiltration rates more than doubled after year two. However, the Peerlkamp method was not sensitive enough to detect visual changes in soil structure over the study period.