Foliar Application of Organic Sorbitol-Chelated Calcium Promotes Peanut ( Arachis hypogaea L.) Growth and Changes Phyllosphere Bacterial Community Structure

Purpose Foliar calcium applications promote peanut growth, but inorganic calcium displays minimal bioavailability, so an organic calcium source is needed. Recent studies showed that sorbitol can convert inorganic calcium to an organic form. However, the effects of foliar applications of organic sorbitol-chelated calcium on peanut growth and phyllosphere bacterial community structure have not been elucidated. Methods We conducted a 2-year field trial to explore how foliar application of organic sorbitol-chelated calcium affected the seed quality, growth parameters, leaf nutritional status, and phyllosphere bacterial community of a Virginia-type peanut (Huayu-22). Results Foliar calcium fertilization promoted calcium absorption by peanut leaves, enhanced carbon and nitrogen metabolism, and promoted peanut growth. Sorbitol-chelated calcium was optimal in these respects. Kernel quality was less affected by foliar fertilization. Foliar fertilization did not affect phyllosphere bacterial community α-diversity but significantly changed the bacterial community structure via changes in the leaf soluble sugar and protein, total carbon, and calcium contents. Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes were dominant phyla and the genera significantly enriched in different treatments differed. Peanut growth was positively correlated with the abundances of Quadrisphaera , Sphingomonas , and unclassified_ p_ Proteobacteria , whereas Klebsiella and Halomonas were negatively associated. Conclusions Overall, we identified an optimal calcium source for foliar application and enhanced the broader understanding of fertilizer-plant-microorganism interrelationships.