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.
Take home messages from the paper include:
- Assessing the yield gap and the level of yield increase that the rainfall of a modified soil site can support, along with season specific effects, is an important step in assessing the risk of sand amelioration options.
- For higher cost interventions knowing the likely longevity of effect is essential. Deep soil disturbance has shown effects for up to four years but it appears that the organic matter treatments tested to date have had most of their effect within two years of application.
- Characterisation of sites across the sandy soils of the Southern cropping region indicated that compaction and a range of nutritional deficiencies are common issues.
- Analysis of herbicide issues flagged glyphosate and the breakdown compound AMPA as residues of interest but their impact is still under investigation.
- Yield responses in 2017 at Ouyen were largely driven by ripping and response to nitrogen (N) input, while at Lameroo, moderate interventions using a fertility band concept had limited impact on a high N background.
- Economic analysis of long-term trials has assessed the return on investment for a range of treatments and highlighted the seasonal response effects on profit-risk.
