Potential impact of future climate change on sugarcane under dryland conditions in Mexico

Assessments of impacts of future climate change on widely grown sugarcane varieties can guide decision-making and help ensure the economic stability of numerous rural households. This study assessed the potential impact of future climatic change on sugarcane grown under dryland conditions in Mexico and identified key climate factors influencing yield. The Agricultural Land Management Alternatives with Numerical Assessment Criteria (ALMANAC) model was used to simulate sugarcane growth and yield under current and future climate conditions. Management, soil and climate data from farm sites in Jalisco (Pacific Mexico) and San Luis Potosi (Northeastern Mexico) were used to simulate baseline yields. Baseline climate was developed with 30-year historical data from weather stations close to the sites. Future climate for three decadal periods (2021-2050) was constructed by adding forecasted climate values from downscaled outputs of global circulation models to baseline values. Climate change impacts were assessed by comparing baseline yields with those in future decades under the A2 scenario. Results indicate positive impacts of future climate change on sugarcane yields in the two regions, with increases of 1%-13% (0.6-8.0Mg/ha). As seen in the multiple correlation analysis, evapotranspiration explains 77% of the future sugarcane yield in the Pacific Region, while evapotranspiration and number of water and temperature stress days account for 97% of the future yield in the Northeastern Region. The midsummer drought (canicula) in the Pacific Region is expected to be more intense and will reduce above-ground biomass by 5%-13% (0.5-1.7Mg/ha) in July-August. Harvest may be advanced by 1-2months in the two regions to achieve increases in yield and avoid early flowering that could cause sucrose loss of 0.49Mgha(-1)month(-1). Integrating the simulation of pest and diseases under climate change in crop modelling may help fine-tune yield forecasting.