Phosphate fertilization in highly weathered soils has been a major challenge for sugarcane production. The objective of this work was to evaluate the foliar levels of phosphorus (P) and nitrogen (N) and the technological quality and productivity of second ratoon cane as a function of inoculation with plant-growth-promoting bacteria (PGPBs) together with the residual effect of phosphate fertilization. The experiment was carried out at the research and extension farm of Ilha Solteira, state of São Paulo, Brazil. The experiment was designed in a randomized block with three replications in a 5 × 8 factorial scheme. The treatments consisted of five residual doses of phosphorus (0, 45, 90, 135 and 180 kg ha⁻¹ of P₂O₅, 46% P) applied at planting from the source of triple superphosphate and eight inoculations from three species of PGPB (Azospirillum brasilense, Bacillus subtilis and Pseudomonas fluorescens), applied in single or co-inoculation at the base of stems of sugarcane variety RB92579. Inoculation with PGPBs influenced leaf N concentration, while inoculations with Pseudomonas fluorescens and combinations of bacteria together with the highest doses exerted a positive effect on leaf P concentration. Co-inoculation with A. brasilense + Pseudomonas fluorescens associated with a residual dose of 135 kg ha⁻¹ of P₂O₅ increased stem productivity by 42%. Thus, it was concluded that inoculations with Pseudomonas fluorescens and their combinations are beneficial for the sugarcane crop, reducing phosphate fertilization and increasing productivity.

This article presents a review on the use of graphene in various segments, elucidating that this product can be used in various industrial sectors. These include mainly agriculture (as in large crops of high relevance, such as coffee), the food industry and the environment, as a plant growth stimulator and in fertilizers, nanoencapsulation and smart-release systems, antifungal and antibacterial agents, smart packaging, water treatment and ultrafiltration, contaminant removal, pesticide and insecticide quantitation, detection systems and precision agriculture. However, some challenges can be overcome before the graphene-based nanoparticle is used on a large scale. In this way, before using the product in the environment, it is necessary to determine whether the technology is safe for the soil-plant system and consumers. Furthermore, the cost of its use can also be a limiting factor depending on the level applied. Therefore, this review proposes to examine the diverse literature to explain the effects of the use of graphene in agriculture, plants and soil microorganisms. Accordingly, this article discusses and presents the possibilities of application of graphene in agriculture, plants and soil microorganisms.