Adapting irrigated and dryland farming systems to climate change and extreme weather events: is simplification or intensification more effective?

Past research has advanced our knowledge of climate change impacts on grassland production and crop yields, yet the resilience of whole farm systems to climate change remains to be quantified. Here we examine how climates in 2040 influence the production and animal feed requirements of dryland and irrigated dairy farms in southern Australia, then contrast the resilience of adaptations that simplified or intensified baseline farm inputs and management. The effects of farm system simplification or intensification on seasonal pasture growth rates in mitigating adverse effects of climate change were small. Relative to historical climates, annual pasture production and livestock pasture consumption in 2040 on dryland farms decreased by ~11% under baseline management or intensification, whereas adaptations that simplified systems resulted in little change in pasture production, pasture consumption or the need to purchase hay. The impact of climate change on annual pasture production and livestock pasture consumption of irrigated farms was less than that for dryland farms. In 2040 the need to purchase hay on the irrigated farm increased by 41% or 104% under baseline management or farming simplification, whereas purchased hay requirement under both historical and future climates under intensification was similar. Collectively these results suggest that the most effective adaptations in mitigating the effects of climate change on dryland and irrigated farms were simplification and intensification, respectively, but future work should address how climate and adaptation scenario influence profitability and risk.