Subsurface Acidity Variability
Towards best practice site-specific mapping, prevention and treatment of subsurface acidity in southern NSW
Funding: National Landcare Program Smart Farms Small Grants – round 2
Project Partners: FarmLink Research, Precision Agriculture
Project Code: 4-BA9KCDK
Project Duration: 2019-20
Project Location: FarmLink Region
Background
A recent focus on subsurface acidity research in southern NSW has highlighted that current data collection methods and liming practices are failing to prevent soil acidification occurring throughout the profile, particularly in the 5-15 cm depth. At the same time, extensive pH mapping in this region has demonstrated that high levels of within-paddock variability of surface pH is common. To date however, there has been no study that examines both the vertical and lateral variability of pH concurrently. This project seeks to do this through an extensive survey of pH variability within 36 paddocks geographically spread throughout southern NSW on a variety of soil types, rainfall regimes and management histories. The relationships between surface and subsurface acidity as well as apparent Electrical Conductivity (ECa), which may act as a proxy indicator, will be used to develop ‘best-practice’ Variable Rate lime decision support methods.