The agricultural use of arbuscular mycorrhizal fungi, such as Rhizoglomus intraradices, can increase the efficiency of phosphate fertilization for the benefit of the corn plant and grain nutrition. In this study, a field experiment was conducted in an area of Selvíria/MS, Brazil, in the years 2019 and 2020, to verify the effects of reduced doses of phosphorus combined with the inoculation of corn seed with R. intraradices on corn plant growth and grain nutrient contents. The experiment was laid in a randomized block design in subdivided plots with four repetitions and twenty treatments resulting from combining five doses of P₂O₅ (0%, 25%, 50%, 75%, and 100% of the recommended dose) with four doses (0, 60, 120, and 180 g ha⁻¹) of an inoculant containing R. intraradices. Leaf and kernel macro- and micronutrient contents were evaluated. The foliar P content in 2020 was a function of the interaction between phosphate fertilization and AMF inoculation, with the highest leaf P content observed at the 100% of P₂O₅ combined with AMF inoculation between 120 and 140 g ha⁻¹. In the grains Mg content, an interaction was observed between the two factors in 2020 and the response surface, showing that the highest Mg content was obtained when maximum doses of P₂O₅ and maximum doses of inoculant were combined. A response surface showed that, in 2020, the highest leaf Zn content occurred when 35–55% P₂O₅ is applied with no inoculation and when P₂O₅ is limited to 20–30%, and there is inoculation with doses between 90 and 150 g ha⁻¹. Phosphate fertilization increased foliar K (2019) and Mg (2020) contents, with maximum points at doses of 76.57% and 88.80%, respectively.

The study was carried out in Selvíria-MS, in the 2011/12 and 2012/13 agricultural years, aiming to evaluate the efficiency of Azospirillum brasilense in nitrogen fixation in upland rice, as a function of doses and application methods of the inoculant containing this diazotrophic bacterium. The experimental design was randomized blocks, arranged in a 4 x 4 factorial scheme, with 4 doses of inoculant (control without inoculation, 100, 200 and 300 mL of the commercial product ha^-1) and 4 application methods (seed inoculation, application in the sowing furrow, soil spraying after sowing, and foliar spraying at the beginning of plant tillering), with 4 replicates. During the experiment, the agronomic characteristics, production components and yield of the rice crop were evaluated. It was concluded that the inoculant containing Azospirillum brasilense promotes increase (19%) in the yield of upland rice under sprinkler irrigation when used at the dose of 200 mL ha^-1, regardless of the application methods.

Large quantities of cover crop residues in the soil, combined, or not, with the inoculation of seeds with diazotrophic bacteria, can increase organic matter (OM) and protect soil microorganisms, such as arbuscular mycorrhizal fungi (AMF) and dark septate endophytic (DSE) fungi. Thus, the use of these sustainable biotechnologies can benefit microbial interactions, soil fertility and rice production in the Brazilian Cerrado region. In this study, we evaluated the effects of maize and Urochloa ruziziensis, intercropped or individually, as cover crops and an inoculation of Azospirillum brasilense on the chemical (fertility) and biological (C–microbial biomass and C–CO₂ released) attributes of soil and the effects of root colonization by AMF and DSE on the yield of rice grown in succession in highlands. The experiment was conducted under field conditions, in a typical dystrophic Red Oxisol. The experimental design consisted of randomized blocks arranged in strips, incorporating a combination of eight residual cover crops: ((1) maize, (2) maize–I (I = inoculation of seeds with A. brasilense), (3) Urochloa (U. ruziziensis), (4) Urochloa–I, (5) maize + Urochloa–I, (6) maize + Urochloa–I, (7) maize–I + Urochloa and (8) maize–I + Urochloa–I). This was accompanied by two treatments of rice as a successor crop (inoculated or not with A. brasilense), with four replicates, totaling 64 experimental units. A cover crop and rice seed inoculation prompted increases in OM and AMF relative to DSE, while the inoculation of rice, regardless of the cover crop treatment, increased the soil’s P content. The combination of maize + Urochloa–I and inoculated rice as the next crop generated increases in its sum of bases (SBs) and cation exchange capacity (CEC). There was a 19% increase in rice grain yields when the seed was inoculated.

In rice, the use of the bacterium Azospirillum brasilense has shown to be very useful for the crop, being able to increase the final productivity of the same or reduce the need for nitrogen in topdressing. It has recently been noted that there are other regulators that perform other functions, such as thidiazuron (TDZ), a cytokinin-like substance that has been shown to significantly increase upland rice productivity. Thus, the present work aimed to verify the effect of the interaction between the foliar application of A. brasilense and thidiazuron doses applied at the occasion of the tillering of the plants on the productive aspects and crop productivity. The experiment was carried out in the agricultural years of 2015/16 and 2016/17, at the UNESP Teaching, Research and Extension Farm belonging to the Engineering Faculty of Ilha Solteira - UNESP, located in the municipality of Selvíria, MS. The experimental design was a randomized complete block design with a 2 x 4 factorial scheme with four replicates. The treatments were the combination of the presence or absence of A. brasilense foliar application with doses of TDZ (0, 0.5, 1.0 and 1.5 g ha^-1) applied to upland rice cultivar BRS Esmeralda. Based on the results obtained for plant height, number of panicles per square meter, total number of grains and fertility of spikelets, mass of 100 grains and grain yield, it was concluded that, in the two agricultural years observed, there were no interaction and individual effects of the foliar application of the bacteria, and of the TDZ doses used at the time of tillering in the BRS Esmeralda cultivar.

A utilização de reguladores vegetais em arroz pode proporcionar redução na altura de plantas e diminuir o acamamento. Objetivou-se verificar a influência da aplicação do regulador vegetal thidiazuron na cultura do arroz de terras altas, em região de Cerrado brasileiro. Utilizaram-se as cultivares BRS Esmeralda e IAC 202, bem como delineamento experimental de blocos casualizados, em esquema fatorial 4 x 3 para cada cultivar, constituído de doses de thidiazuron (0 g ha^-1; 0,3 g ha^-1; 0,6 g ha^-1; e 0,9 g ha^-1) e três épocas de aplicação (perfilhamento, diferenciação floral e emborrachamento), com quatro repetições. O número de espiguetas por panícula e fertilidade das espiguetas da cultivar BRS Esmeralda foram maiores utilizando-se a dose de 0,9 g ha^-1 de thidiazuron, com aplicação na fase de perfilhamento. A massa de 100 grãos da BRS Esmeralda se ajustou a uma equação quadrática, enquanto, para a IAC 202, houve ajuste a uma equação linear, com melhor época de aplicação durante o perfilhamento. Para massa hectolítrica da BRS Esmeralda, os resultados também se ajustaram a uma equação quadrática, enquanto, para a IAC 202, houve diferença significativa apenas entre as épocas, sendo o emborrachamento a melhor época de aplicação. As produtividades de grãos da BRS Esmeralda e IAC 202 apresentaram ajuste linear positivo, com ganhos de 23,5 % e 6,5 %, respectivamente, em relação à testemunha. O thidiazuron influencia positivamente na produtividade da cultura do arroz de terras altas.

The symbiosis of common beans with nitrogen-fixing bacteria provides an efficient approach to sustainable and economical food production. Therefore, this study aimed to evaluate the application of cost-effective nitrogen management strategies in organic common bean cultivation, including the application of poultry manure and organic liquid fertilizer, seed and co-inoculation with diazotrophic bacteria (Azospirillum brasilense and/or Rhizobium tropici), and supplementary Rhizobium tropici inoculation. The study spanned three years in a well-established organic cultivation field (2018) and an initial organic cultivation area (2019 and 2020) in Brazil. It was arranged in a randomized blocks design in a 2 × 5 (2018) and 2 × 6 (2019 and 2020) factorial scheme, with four replicates. The most profitable strategy involves seed inoculation with Azospirillum brasilense and additional inoculation with Rhizobium tropici at stage V_4-5 (fifth trifoliate leaf fully expanded), while the most costly strategy was the application of poultry manure at the V₃ stage (first trifoliate leaf fully expanded). Thus, the use of diazotrophic bacteria for seed inoculation and co-inoculation (Azospirillum brasilense and/or Rhizobium tropici) ensured financial returns and system profitability in common bean cultivation.