Farm Table says:
The take home messages from this GRDC funded research are below. Please access the full paper via the link below for methodology, references, acknowledgements and discussion.
Subsurface acidity and stratification are emerging as serious constraints to crop production across SA, NSW, Victoria, and WA.
Traditional soil sampling strategies can lead to misdiagnosis of subsurface issues; strategic sampling at specific depth intervals is required.
Lime rates need to be adjusted to account for subsurface pH, changes in soil texture and organic carbon content down the profile.
Strategic incorporation/tillage can aid the efficacy of lime application for treating subsurface issues; other subsoil constraints (e.g. compaction) should be taken into consideration to maximise treatment impact, along with the risks associated with soil disturbance.
Options for treating subsurface and stratification issues are being examined in the new GRDC Acid Soils SA Project.
Table 1. Severity of acidity as determined using a pH indicator kit, which is equivalent to the pH in water (pHW).