Soil pH in northern and southern areas of the WA wheatbelt

More than 80% of the topsoils sampled fall below the critical surface pHCaCl2 of 5.5 in the northern and southern wheatbelt study areas, with more in the south than the north. These results confirm soil acidity is a serious concern throughout the WA wheatbelt when considered in conjunction with the more intensive analysis of current soil pH throughout the Avon River Basin (2005–2008). With low topsoil pH, it is likely that subsurface acidity is also a problem. For soil acidity to be managed, subsurface pH also needs to be known. In the Avon River Basin study, about half of the subsurface samples fell below the critical subsurface pH of 4.8. Maintaining soil pH above 5.5 in the topsoil and 4.8 in the subsurface will remove soil acidity and aluminium toxicity as a constraint to sustainable productive agriculture in the WA wheatbelt.https://library.dpird.wa.gov.au/bulletins/1199/thumbnail.jp