Impact of the microalgae-bacteria interaction on maize (Zea mays L.) health and yield

Abstract

Microbial biofertilizers, which include microorganisms that improve soil nutrients and make them easier to cultivate, are eco-friendly alternatives to chemical fertilisers, encouraging plant growth and supporting sustainable agriculture. The purpose of the study was to evaluate the health of crops measured by the normalized difference vegetation index (NDVI) and yield, influenced by the combination of biomass from specific cyanobacteria (MACC-612, Nostoc linckia) and plant growth promoter bacteria (PGPB). Using a factorial design in a complete randomized block configuration, four replications were performed. The experimental design included the testing of three concentrations of microalgae (untreated, 0.3 g/L N. linckia, and 1 g/L N. linckia) and two PGPBs (untreated, Azospirillum lipoferum, and Pseudomonas fluorescens). Experiments in the field were conducted for three consecutive years (2021, 2022, and 2023). The results show that the combined application of N. linckia and PGPB to soil treatment has significantly improved plant health and yield characteristics. The combined use of 0.3 g/L N. linckia and A. lipoferum has improved the health of plants (NDVI), seed count per cob, thousand-seed weight, and total yields, achieving a significant increase of yield by 1.4 fold for 2021, 1.37 fold for 2022, and 1.39 fold for 2023. These results demonstrate that applying low concentrations of N. linckia (0.3 g/L) along with A. lipoferum provide a costeffective solution without compromising the benefits. Consequently, the integration of cyanobacteria and PGPB represents a promising approach to improve crop growth and yield while minimizing environmental impacts.