BioProject

of ethanol and sugar production. The composting process emerges as an alternative solution for these wastes, transforming them into a secondary product bearing a solution to improve sugarcane mineral nutrition, especially for phosphorus (P) uptake. More...

of ethanol and sugar production. The composting process emerges as an alternative solution for these wastes, transforming them into a secondary product bearing a solution to improve sugarcane mineral nutrition, especially for phosphorus (P) uptake. Microorganisms play an essential role in the P cycle, especially on its transfer to the plant. Phosphate-Solubilizing Bacteria (PSB) can improve soil P availability, elevating crop productivity. Thus, to improve P uptake, it is crucial to understand the soil microbial community and P availability when applying compost and PSB, and this was the objective of our paper. We used different sources of P (compost, rock phosphate, compost + rock phosphate, triple superphosphate (TSP), TSP + compost, and a control without P) and two PSB inoculants to evaluate their effect on sugarcane yield in a greenhouse experiment. Inoculum 1 consisted of a consortium of Pseudomonas sp. PSBR10, Azotobacter sp. AZTBR19, and Rhizobium sp. RIZBR01, while Inoculum 2 contained Bacillus simplex BACBR04, Bacillus sp. BACBR06, and Rhizobium sp. RIZBR01. We evaluated the P, N and K content in sugarcane shoots and performed a sequential soil P fractionation, as well as characterized the soil bacterial community, using high-throughput sequencing of the bacterial 16S rRNA gene. Our data demonstrate that inoculant applications improve nutrient accumulation mainly with compost as a P source. Using compost as P source and applying inoculum 2 we found significant increments in P, N and K accumulation when compared to the control without inoculation or with the treatment in which the P source was TSP. Compost applications and PSB inoculation improved soil P availability, resulting in a higher P, N and K accumulation. Hence, we conclude that the application of this PSB consortium together with sugarcane residues compost modifies the bacterial community and improves P nutrition in sugarcane. These results open a new perspective for the use of such a bacterial consortium in combination with organic compost as fertilizers to optimize P acquisition and growth in sugarcane. Less...