Impact of climate change on schedule irrigation events for organic tomato production

Abstract

This study aimed to evaluate the use of irrigation scheduling strategies to enhance irrigation management in organic tomato production, and to analyze the effect of climate change on tomato crops in Alabama through the use of crop modeling. Field experiments were conducted on the organic unit at E.V. Smith Research and Extension Center from Auburn University, located in Shorter, AL in 2022 and 2023. Three irrigation scheduling treatments were tested: systematic irrigation (SYS), crop water demand (CWD), and soil water status method (SWS). Results indicated that SWS had a higher biomass accumulation, consequently increased yield compared to the two other treatments. Furthermore, irrigation water savings were the highest for the SWS treatment, resulting in 72% water savings compared to SYS and 54% to CWD in 2022. In 2023, SWS used 65% less water than SYS, and 55% less than CWD. Data from the field was populated into the CSM-CROPGRO Tomato model, in which crop simulation performance was acceptable with the lowest R2 being expressed for leaf dry weight (0.91), while the highest was for the soil water content (0.99). A seasonal analysis presented the impact of air temperature and rainfall events indicated a significant decrease in fruit production as temperature increases. Under the worst-case scenario (i.e., 6 oC temperature increase) of this study, tomato production decreases by roughly 87% for SWS and 73% for SYS irrigation treatment, while water use for SWS increases 2.7 times for the same scenario. In conclusion, climate change may negatively affect tomato production due to high-temperature plant exposure. In contrast, due to the high biomass production under higher temperatures, irrigation water volume may increase, making the crop production cost rise for growers, and consequently increasing consumer prices.