Background:Research aimed at improving crop productivity often does not account for the complexity of real farms underpinned by land-use changes in space and time.

Methods: Here, we demonstrate how a new framework – WaterCan Profit – can be used to elicit such complexity using an irrigated case study farm with four whole farm agronomic scenarios (Baseline, Diversified, Intensified and Simplified) with four types of irrigated infrastructure (Gravity, Pipe & Riser, Pivot and Drip).

Findings:Without adaptation, we show that the climate crisis detrimentally impacted on farm profitability due the combination of increased evaporative demand and increased drought frequency. Whole farm intensification – via greater irrigated land use, incorporation of rice, cotton and maize and increased nitrogen fertilizer application – was the only adaptation capable of raising farm productivity under future climates. While Diversification through incorporation of grain legumes significantly improved profitability under historical climates, profitability of this adaptation declined under future climates. Simplified systems reduced economic risk but also had lower long-term economic returns.

Conclusions:We conclude with four key insights: (1) when assessing whole farm profit, metrics matter: Diversified systems generally had higher profitability than Intensified systems per unit water, but not per unit land area; (2) gravity-based irrigation infrastructure required the most water followed by sprinkler systems, while Drip irrigation used the least water, (3) whole farm agronomic adaptation through management and crop genotype had greater impact on productivity compared with changes in irrigation infrastructure, and (4) only whole farm intensification was able to raise profitability under future climates.