Re-evaluating the rationale for irrigation technology adoption through an integrated trade-off analysis: case study of a cotton farming system in Australia

While the prevailing rationale for new irrigation technology adoption is improved water use efficiency, this study evaluated trade-offs between water savings, greenhouse gas (GHG) emissions and economic gain associated with the conversion of a furrow irrigation system to a sprinkler irrigation (lateral-move) system on a cotton farm in eastern Australia. Trade-offs were evident when conversion to the pressurised sprinkler irrigation system was evaluated in terms of fuel and energy-related emission; the adoption of the new system saved water but increased GHG emissions. However, when we considered changes in farm machinery and input uses as a result of the conversion, we found an overall reduction in GHG emissions. Overall, the GHG modelling indicated that higher total quantities of GHGs were emitted from the furrow irrigation (4,453 kg CO₂e/ha) than from the sprinkler irrigation (3,347 kg CO₂e/ha) farming system. Water efficiency modelling indicated that, on average, water savings of 18% are possible, while economic modelling indicated that the conversion of irrigation technology is a viable option. Even at a carbon price of AUD$30/tCO₂e, investment in the sprinkler technology was an economically feasible option due to significant water savings and increased yield.