This research analyzed the effects of inoculation with Rhizobium tropici, combined with beneficial microorganisms, on the reduction of NPK fertilization and its impacts on common beans. Conducted in two types of soil (clayey Oxisol and sandy Ultisol), the experimental design was a randomized block design under a factorial scheme 4 × 4, with different combinations of inoculation (Rhizobium tropici alone or in combination with Azospirillum brasilense, Bacillus subtilis, and Trichoderma harzianum) and fertilization doses (0%, 33%, 66%, and 100% of the recommended dose). The results showed that inoculation with R. tropici, especially in combination with Trichoderma harzianum, increased nodule formation and improved agronomic parameters such as leaf chlorophyll, dry matter of the plant, number of pods, and grains. Co-inoculation with Azospirillum brasilense resulted in a significant increase in grain yield, particularly in clayey soil with 33% NPK. Inoculation with lower doses of NPK was sufficient for good yield, suggesting the feasibility of reducing the use of mineral fertilizers. This study indicates that soils with corrected fertility, in a no-tillage system, can contribute to the reduction of fertilizer use due to the cycling of organic matter and improvement of soil health. Additionally, the use of microorganisms is an effective ally for the sustainability of agroecosystems.

A Passiflora caerulea L. além de apresentar importância gastronômica e medicinal vem sendo utilizada como porta-enxertos de maracujá comercial, mediante resistência a doenças fitopatogênicas. Entretanto, essa espécie apresenta suscetibilidade a patógenos virais e baixa taxa de germinação. Nesse aspecto, a cultura de tecidos torna-se uma alternativa viável por proporcionar a produção em larga escala, em curto período de tempo e livre de doenças virais, sendo assim uma ferramenta de extrema importância na preservação e propagação dessa espécie. No entanto, existem poucos estudos relacionados ao cultivo in vitro de P. caerulea. Dessa forma, o objetivo deste trabalho foi estabelecer um protocolo de cultivo in vitro para essa espécie. Foi utilizado o meio de cultivo MS com 100% e 50% das concentrações de sais (MS 100% e MS 50%). Para execução desse experimento, inicialmente foi realizada a morfometria das sementes de P. caerulea, com intuito de escolher o material seminífero para posterior germinação. Em seguida, microestacas oriundas de plantas germinadas a partir dessas sementes foram inoculados em meio MS 100% e MS 50%, sem adição de fitormônios. O experimento foi conduzido em delineamento inteiramente casualizado com 25 repetições, do qual foram avaliados o número de gemas, comprimento da brotação, número de folhas, coloração da folha e desenvolvimento da microestaca. A utilização do meio MS 50% se mostrou viável para o estabelecimento in vitro de P. caerulea, sem o comprometimento no desenvolvimento e da qualidade das plantas, proporcionando redução dos custos na produção do meio de cultivo.

Soybean is a crop of significant economic importance, with its grains serving various purposes. In a scenario of increasing demand for food and environmental challenges, bioinputs emerge as effective alternatives to achieve sustainability. Thus, this study aimed to evaluate the co-inoculation of Bradyrhizobium japonicum and Bacillus aryabhattai, associated with potassium silicate doses in soybean cultivation. The experiment was conducted under field conditions using a randomized block design arranged in a 2 × 5 factorial scheme with four replications. The first factor consisted of microorganism inoculation (Bradyrhizobium japonicum and B. japonicum + Bacillus aryabhattai), and the second factor comprised foliar potassium silicate doses (0, 1.50, 2.50, 3.50, and 4.50 L ha⁻¹), applied in two growth stages (R2 and R3). A total of ten treatments were evaluated. The experimental plots consisted of eight rows, each five meters long, with a distance of 0.5 m between rows. The observational area of the plot comprised the four central rows, excluding one meter from the ends of the rows. Co-inoculation of B. japonicum and B. aryabhattai resulted in increased plant height but decreased the number of reproductive nodes compared to inoculation with B. japonicum alone. Inoculation with B. japonicum significantly increased the number of pods per plant and 100-grain weight. Co-inoculation with B. japonicum and B. aryabhattai and foliar application of potassium silicate doses did not influence K and Si contents in straw and grains and soybean grain yield.

Beneficial microorganisms enhance phosphorus (P) use efficiency in common bean, compensating for its shallow root system. Integrating biological approaches with reduced P rates optimizes plant growth, improves yield, lowers costs, and advances sustainable agriculture. This study aimed to assess the effects of seed inoculation with Trichoderma harzianum and/or Bacillus amyloliquefaciens associated with reduced P fertilization on common bean (Phaseolus vulgaris L.) agronomic and nutritional performance. The experiment was conducted under greenhouse conditions using a Quartzipsamment Entisol soil. Inoculation with B. amyloliquefaciens or T. harzianum, regardless of the P rate, as well as co-inoculation under the full phosphorus rate, increased grain yield by 64.4%, 31.9% and 49.4%, respectively, compared with the non-inoculated control under the full phosphorus rate. Regarding total phosphorus accumulation, inoculation with T. harzianum increased P accumulation by 90%, and co-inoculation increased it by 72%, compared with the non-inoculated control. The use of B. amyloliquefaciens and T. harzianum in common bean cultivation can enhance nutritional status (57% for total N accumulation, 40% for P, 93% for K, 33% for Ca, 31% for Mg, 50% for S) and grain productivity (44%), even with a 40% reduction in phosphorus fertilization in sandy soils with very low P availability, under greenhouse conditions.

Silicate rocks represent alternative K sources when finely ground, reducing production costs and dependence on imported fertilizers. Therefore, this study aimed to evaluate the effects of potassium (K) dose, application timing, and fertilizer sources on the concentrations and accumulation of K, silicon (Si), and sodium (Na) in maize diagnostic leaves, straw, and grains under a no-tillage system in Savanna. The soil was classified as Typic Haplustox (Oxisol). The experiment followed a randomized block design in a 2 × 4 × 3 factorial scheme, with two application times (30 days before sowing soybean and at sowing soybean), four K₂O rates (0, 40, 80, and 120 kg ha⁻¹), and three sources (KCl, Potasil, and Ekosil). K fertilization was applied by broadcasting without incorporation, before the preceding crop. Potasil provided a higher foliar Si concentration, and Si accumulation in grain and straw increased with the increment of K fertilization using the Potasil. Early fertilization promoted greater K accumulation in maize straw. For grain K accumulation, moderate K₂O doses favor greater accumulation, with Ekosil and Potasil showing superior results compared to KCl. There was less sodium accumulation in the grains with Ekosil compared to KCl. Agronomic efficiency is maximized at 40 kg ha⁻¹ of K₂O, with Ekosil showing the best performance for maize crop. These findings indicate that alternative K sources, applied at optimized rates, improve crop nutrition and promote sustainability in soybean–maize crop rotation.