Impact of climate change on rainfed sugarcane in Veracruz, Mexico

Resumen

Objective: To estimate the expected quantitative changes of the rainfed sugarcane yield in four sugar mills in the state of Veracruz using climate change scenarios for the end of the 21st century and considering that the same climate change could also affect soil fertility.

Design/methodology/approach: The data on the cultivated area with the rainfed sugarcane such as topography, principal properties of soil fertility, crop yields for the beginning of the 21st century, current climatic data from the meteorological stations and future ones based on existing climate change scenarios were analyzed. Then, by means of a physiological model of this crop based on biological, climatic and soil characteristics, proposed by IIASA/FAO, the current and future agricultural productivity of sugarcane was calculated. The actual productivity calculated with this model was compared with the observed data. Then, the productivity of this crop for the end of the 21st century was calculated. The comparative impact on the productivity of the expected changes in some climatic components and corresponding expected modification in soil fertility was assessed.

Results: The results of calculations indicate that if the CO₂ concentration in the atmosphere increases by 2 or 2.7 times at the end of the 21st century and the current varieties of sugarcane and their crop management will conserve, the yield of sugarcane will decrease up to 20% depending on the climate change scenario and location of the plot. The main climatic factor influencing the decrease in sugarcane productivity is the expected decrease in precipitation.

Limitations on study/implications: Monthly average climatic variables are used for both current and future productivity calculations since there are no estimates of daily data. There are also no predictions on the development of crop management technology as well as on the expected change in pests and diseases for the end of the 21st century.

Findings/conclusions: The IISA/FAO physiological model of sugarcane growth based on agroecological principles, considering even limited number of climatic variables, is useful for calculating of sugarcane productivity with correlations greater than 90% for calculated and observed data. This allowed us to estimate the expected impact of climate change in the productivity of rainfed sugarcane in Veracruz State of Mexico at the end of 21st century.