FutureSheep – What will pasture production look like in south-west Western Australia in 2050?
Document Type
Conference Proceeding
Publication Date
10-2024
Conference Title
Adaptive Agronomy for a Resilient Future
Place of Publication
Albany
Keywords
Future climate, forage biomass, plant growth, simulation modelling, mediterranean climate
Disciplines
Agronomy and Crop Sciences | Climate | Sheep and Goat Science
Abstract
The south-west agricultural region of Western Australia (WA) has become drier and hotter since the 1970’s and future projections indicate this trend will continue – presenting challenges for pasture and livestock production. To help producers adapt to this change in climate, we used the GrassGro™ simulation model to predict pasture productivity in 2050 for eight farming locations in WA. Climate data for 2050 was generated for two greenhouse gas (GHG) pathways, RCP 4.5 and RCP 8.5 (Representative Concentration Pathways), using change factors from the Climate Change in Australia website. Using these factors, daily rainfall and temperature for 2050 was calculated using historical 2002-2021 data. Atmospheric CO2 levels were set at 395 ppm for the current climate, 500 ppm for 2050 RCP 4.5 and 610 ppm for 2050 RCP 8.5. All model simulations were conducted on ungrazed annual pastures run for 20 years. GrassGro™ was validated for each of the case study sites using the Pastures from Space ™ data for the period 2004 to 2021. The resulting simulations suggest that all sites will experience a loss in annual pasture yield by 2050, with the lower emission pathway (RCP 4.5) resulting in the least reduction in most cases. With an RCP of 4.5 the yield at low to medium rainfall sites is expected to decline by an average of 20% compared to only 6% at higher rainfall sites. The results also suggest that the growing season in 2050 will be shorter at all sites. To maintain current pasture productivity in 2050 will require feedbase adaptation such as increased soil fertility, the adoption of annual or perennial pasture species that can produce similar amounts of dry matter with less rainfall in a shorter growing season and the introduction of summer-active forages.
Recommended Citation
Sanford, P., Guthrie, M., Farre, I., Kharel, S., Revell, C., Conte, J., Foster, K. (2024). FutureSheep – What will pasture production look like in south-west Western Australia in 2050?. In: Proceedings of the 21st Australian Society of Agronomy Conference, Albany, Western Australia. (http://www.agronomyaustraliaproceedings.org/).
