Project code: No code
Project manager: MFMG team
Project duration: July 2020 to May 2021
About the project
There are more than 2.2 M ha of sandy soils in the Murray Mallee and South East regions of South Australia that are prone to develop poor fertility. Despite improvements in crop management and agronomy, there is often a large gap between the potential grain yield that could be achieved, based on rainfall, and the actual yields of crops grown on sandy soils.
Underlying soil constraints that contribute to this ‘yield gap’ include physical and chemical impediments that are inherent (naturally derived) and may be outside a farmer’s control for treatment, and others that are more dynamic, meaning they can change over time with different management practices.
The most common chemical and physical constraints encountered in sands throughout the Southern Mallee and Upper South East regions are:
- Water repellence
- Stratified and subsurface acidity and alkalinity
- Poor nutrient fertility and water holding capacity
- Salinity and subsoil sodicity
- Compaction and hard setting
These constraints rarely occur in isolation and together result in poor root growth and crop water-use, severely impacting grain yields. However, there are a range of emerging treatment strategies that can be employed to combat these constraints, including low cost solutions that are applied annually, and higher intervention, higher cost strategies that result in longer lasting, or permanent, results.
Methods to diagnose these key constraints on-farm are presented, along with assessment of the yield gap, and options for their treatment.
