Variable aluminium toxicity and root distribution in acidic soil profiles

Subsoil acidity currently affects two thirds of the arable soils in the WA wheatbelt. At acidic soil pH, aluminium (Al) is solubilised from the solid phase into soil solution, creating a direct and localised toxicity to plant roots. Aluminium toxicity to plant roots constrains crop productivity by reducing root proliferation through soil, and inhibiting the capacity of roots to tolerate other constraints, such as compaction. Ongoing acidification of the subsoil is a direct artefact of the productive farming systems that are required to feed our world’s growing appetite for grain and livestock products