CARBONATITO FOSFÁTICO E MICRORGANISMOS BIOSSOLUBILIZADORES COMO ESTRATÉRGIA PARA SUPRIMENTO DE FÓSFORO NA CANA-DE-AÇÚCAR

Abstract

Phosphorus (P) is an essential nutrient for sugarcane (Saccharum spp.); however, its low availability in Brazilian tropical soils and the dependence on imported fertilizers demand sustainable management alternatives. This study aimed to evaluate different P sources, combined or not with biosolubilizing microorganisms, on physiological and bromatological parameters of the crop. The experiment was carried out under greenhouse conditions, in a randomized block design, with treatments consisting of 100% phosphate rock (CF), 50% CF + 50% single superphosphate (SFS), and 100% SFS, at a rate of 350 kg ha-1 of P2O5, associated with the inoculation of Bacillus amyloliquefaciens, Bacillus aryabhattai, Cladosporium cladosporioides, and Trichoderma harzianum, either individually or in co-inoculation. Ninety-five days after planting, tillering, number of nodes and internodes, stalk length, fresh and dry biomass of shoots and roots, and SPAD index were evaluated. Results showed that the 50% CF + 50% SFS arrangement had a statistically similar performance to 100% SFS in the most relevant agronomic traits (biomass, stalks, and shoot development), surpassing the 100% CF treatment. Microbial inoculation enhanced dry matter accumulation, especially in roots, with remarkable effects for T. harzianum and co-inoculation of Bacillus + Cladosporium when associated with more soluble P sources. From an agronomic perspective, at the initial growth stage of sugarcane, the combination of P sources together with biosolubilizing microorganisms represents a promising alternative to reduce the dependency on imported fertilizers, reconciling productivity and sustainability.