Efficiency of phosphate-solubilizing bacteria on maize growth under phosphorus application rates

Abstract

Abstract Brazil is the world's third-largest corn producer, which is considered a demanding crop in terms of soil fertility. Phosphorus is known to be an essential element for crop development, and in most arable areas, this element is found in a form that is poorly available to the plant. Therefore, the objective of this study is to evaluate the influence of phosphorus-solubilizing bacteria (Bacillus subtilis, B. megaterium, and B. aryabhattai) on the availability of this nutrient, combined with phosphate fertilizer doses, on early corn development. A completely randomized experimental design was used in a 2 x 3 factorial arrangement, consisting of six treatments and five replicates. The treatments consisted of treatment with or without the bacteria and three phosphorus doses (0, 50, and 100% of the P dose). The evaluations performed included stem diameter, root length, shoot and root dry matter, chlorophyll index, and shoot phosphorus content. Data were analyzed by ANOVA (F-test). Means for inoculation treatments were compared using Tukey’s test, while phosphorus rates were evaluated by linear regression. Inoculation with Bacillus spp. significantly increased final plant height, root length, and dry matter accumulation, while chlorophyll index, stem diameter, and shoot phosphorus content did not differ significantly from the inoculant. Increasing phosphorus doses significantly increased plant height, root length, dry matter, and shoot phosphorus content, but did not significantly influence chlorophyll index or stem diameter. The interaction between inoculant use and phosphorus doses was not significant for any of the variables evaluated. These results indicate that inoculation with Bacillus spp. can promote vegetative development at later stages, while phosphorus is crucial from the early stages of the crop.