Farm Table says:
What is the problem?
Deep drainage to groundwater in the Broken Plains area has been predicted to bring the water table to within two meters of the surface over the next 66 years. However, with reduced rainfall as a result of climate change, this may not happen for 113 years. The rising water table will lead to waterlogging and dryland salinity. A solution is to introduce deep-rooted perennial species such as lucerne. Lucerne extracts more water than annual crops and pasture.
What did the research involve?
The case study research method was used. Case study research is about why decisions were made, how they were implemented and the results from making the decisions (Yin 2003, p.13). Accordingly, six farmers who had made the switch from cropping with subterranean clover to cropping with lucerne were the subjects for case study research. These farmers represented the multiple sources of evidence required in case study research and were questioned about why they changed their farming system, how they implemented the change and the net benefits that they believed they received as a result of adopting the innovation
What were the key findings?
Results of this analysis show that private investment decisions to change to cropping with lucerne as the legume component in the crop sequence, instead of subterranean clover, increases expected profitability and cumulative net cash flow of crop sequences. Still, farmers in this area generally believe that Lucerne is riskier than annual legume pastures which constitutes a barrier to its widespread adoption. From the public perspective, keeping water tables below two meters prevents damage to infrastructure, roads, wetlands, and biodiversity.
The crux of the problem that this study seeks to inform is that, if farmers on the Broken Plains sub-catchment changed from cropping with subterranean clover to cropping with Lucerne, the extra economic benefit to the Broken Plains sub-catchment, and hence to the Australian economy, expressed in 2008 dollar values would amount to an estimated $31.26 million over 90 years for the scenario without climate warming or $19.3 million over 134 years for the scenario with climate change.