Adapting to Climate Change
Simple adaptation has the potential to alleviate most of the financial impacts from predicted climate change in South West Victoria according to a project recently completed by Southern Farming Systems.
The work, supported by the Australian Government’s Future Drought Fund, involved 32 farms that manages 55,000 ha of land stretching from the Bellarine Peninsula to the South Australian Border, which included businesses with farming systems of livestock only, mixed and crop only.
The work involved modelling crop and pasture production from 1990 to 2009 and comparing this to future growth predictions for a period from 2020 to 2039 with the same farming practices.
Grace Evans, from the project team at Southern Farming Systems said “the calculations generated some interesting results. As expected, the predicted lower rainfall and warmer temperatures decreased livestock carrying capacity by about 8 %, however in very wet cold years, warmer and drier conditions were helpful to the farming system”.
“Wheat yields from late maturing varieties were predicted to decline by between 0 and 1.8 t/ha, canola by 0.1 to 0.2 t/ha, barley by +0.9 to -1.1 t/ha and faba beans +0.7 to -0.8 t/ha” she said. The yield losses were more pronounced in locations that already have less rain and a shorter growing season.
Each farmer in the study provided information to calculate their historic farm operating profit. This required information on yields, stocking rates, prices and costs. Ranges rather than single values were used when the input was unpredictable from year to year, such as yields, prices, lambing % and supplementary feeding.
“Using a sophisticated computer program called @Risk, we were able to see the impact these production changes with a changing climate would have on farm profit into the future” Grace said. The results were revealing if no changes were made to the current farming system. While there was a high degree of variability between businesses, the average values across all farms showed farm profit under a future climate scenario was estimated to decreased by $72/ha. The chances of making a loss increased from 1 year in 4 to 1 year in 3, although the size of the losses were relatively small in most cases. A few farms in historically ‘wet’ locations increased profit under the climate change scenario because of more favourable growing conditions.
A positive insight from the analysis was the opportunity to adopt some simple changes to negate the predicted production losses. These included actions such as choosing slightly shorter season length crop varieties, increasing pasture growth through better soil fertility, increasing pasture utilisation with enhanced grazing management and adjusting enterprise mix.
“While farmers should be preparing for the impacts of climate change, our analysis shows that some relatively easy changes can go a long way to mitigate the anticipated climate impacts on profit” Grace said.
For more information on the project and final reports go to https://sfs.org.au/project/building-drought-resilience or come along to AgriFocus 18 October at Streatham to hear a keynote session on the project.