Comparison of Effects of Foliar Fertilizer Application of Hydrogen Water on Leaf Lettuce

Hydrogen water, characterized by a high concentration of unionized hydrogen molecules, is being presented as a new alternative in agriculture. This study focused on the application of hydrogen water to leaves and its effects on crop yield and quality, especially on leaf lettuce, through foliar fertilization (twice a week at 25 L per 330 m2) experiments with hydrogen water with dissolved hydrogen of more than 300 ppb and control water with dissolved hydrogen close to 0 ppb. The experimental group that received foliar fertilization showed significant advantages over the control group in leaf thickness and stem thickness characteristics that affected post-harvest distribution quality. Area growth rate analysis revealed a consistently higher average area growth rate (up to 0.86%) in the group treated with hydrogen water compared to the control group (0.1%). The results of an independent-sample t-test of spectral indices showed that the experimental group showed a significance level above the critical value (p < 0.05) compared to the control group in the analysis results of NDVI in soil cultivation and NDRE in hydroponic cultivation. Although other spectral indices did not show differences between the experimental and control groups at the significance level, the average of all samples was higher in the experimental group than in the control group. Overall, the findings suggest that foliar application of hydrogen water positively influences the growth of lettuce crops, as evidenced by comprehensive trait, area growth rate, and spectral index analyses. These results underscore the novelty of hydrogen water as an efficient foliar treatment that enhances crop performance with minimal system changes. Its potential to improve yield quality while reducing chemical input demands suggests clear economic and environmental benefits.