DEVELOPMENT AND INITIAL NUTRITION OF CORN WITH BIOMAPHOS® INOCULANT ASSOCIATED WITH PHOSPHATE SOURCES

Abstract

Brazilian soils have mineralogical characteristics that favor the adsorption of phosphorus (P) and this reduces the efficiency of phosphate fertilization. One strategy to increase the accessibility of residual P (legacy P) in the soil to plants is using phosphate-solubilizing microorganisms. Here, the objective was to evaluate the initial development and nutrition of corn, and soil chemical attributes after inoculation of BiomaPhos^® associated with high and low solubility phosphate sources. The experiment was carried out in a randomized block design greenhouse in a factorial scheme (2x2) with six replications. The first factor was reactive rock phosphate and triple superphosphate, and the second factor was the inoculation or not of BiomaPhos^®. The fertilizers were applied in pots with a capacity of 5 dm³ of soil, and the inoculants were applied to the seeds at the time of sowing. Biometric parameters, soil chemical attributes, leaf P content, and accumulation in corn at 45 days after emergence (DAE) were evaluated. There was a significant interaction (p<0.05) between the effect of P sources and the inoculant for the variables: collar diameter (CD); root and shoot dry mass (MSR and MSPA); shoot-to-root ratio (RPAR); total dry mass (TDM); leaf P (LP); absorption of P (PA); and pH. Therefore, the association between P-solubilizing inoculants, and phosphate fertilizers promoted root biomass growth and altered the availability and absorption of P during the 45 DAE of the corn crop. BiomaPhos^® was more efficient in a low solubility (FN) source, and its effects are null or negative with soluble P sources. That is, the microorganisms modulate the development of corn, which verified positive responses from the accumulation of biomass, content, and P uptake from corn at stage V6.