A B S T R A C TIn search of a more sustainable agriculture, the use of beneficial microorganisms has been highlighted, because they are low-cost and can reduce the use of fertilizers and increase grain yield. The present study aimed to evaluate the efficiency of A. brasilense inoculation and the best form and dose of inoculation in maize, measuring the impact on some physical characteristics and on its nutrition. The experiment was conducted in a greenhouse, in Ilha Solteira, SP, Brazil, in a completely randomized design, with four replicates and eight treatments: 1) control; 2) Seed 1x; 3) Seed 2x; 4) Soil 1x; 5) Soil 2x; 6) Leaf 1x; 7) Leaf 2x; 8) Seed 1x + Leaf 1x, respectively representing in each treatment the site and dose of application (1x, dose recommended by the manufacturer; 2x, twice the dose recommended by the manufacturer). No differences were found in any physical characteristics evaluated between treatments; however, for nutrient contents in the leaf tissue, there was effect on Zn content. It was concluded that, regardless of the presence of A. brasilense inoculation, forms or dose (in hybrid DKB 350), in general, there were no improvements in the characteristics evaluated. Doses e formas de inoculação com Azospirillum brasilense na cultura do milho R E S U M O Microrganismos benéficos vem sendo amplamente aplicados na agricultura, por possuírem baixo custo e possibilitarem a redução da utilização de adubos e incrementos na produtividade de grãos. Com o presente trabalho, objetivou-se determinar o efeito de doses e formas de aplicação do inoculante Azospirillum brasilense na nutrição de planta e na produção da cultura do milho. O experimento foi realizado em casa de vegetação, no município de Ilha Solteira, SP, em delineamento inteiramente ao acaso, com quatro repetições e oito tratamentos: 1) Testemunha; 2) Semente 1x; 3) Semente 2x; 4) Solo 1x; 5) Solo 2x; 6) Foliar 1x; 7) Foliar 2x; 8) Semente 1x + Foliar 1x, sendo, respectivamente dentro de cada tratamento, o local e a dose de aplicação (1x, dose recomendada pelo fabricante; 2x, dobro da dose recomendada pelo fabricante). Não foram verificadas diferenças para os tratamentos avaliados, nas características avaliadas, já para as concentrações de nutrientes no tecido foliar, houve efeito somente para o Zn. Concluiu-se que, independente da presença de inoculação, da forma ou da dose de A. brasilense avaliada, no híbrido DKB 350, de modo geral, não houve melhorias nas características avaliadas e na nutrição da cultura do milho.

Despite maintaining the green color in turfgrasses, nitrogen (N) fertilization affects shoot growth and, consequently, the frequency of cuts, the main factor in the costs of turfgrass maintenance. Therefore, this study aimed to evaluate N fertilization and the use of glyphosate as a growth regulator in Esmeralda grass (Zoysia japonica Steud.). The experiment was conducted in the field, from August 2014 to July 2015, using a randomized block design in a 5 x 4 factorial scheme with four repetitions and 20 treatments, namely: control (without N), 15 g m-2 of N in soil without foliar N; 30 g m-2 of N in soil without foliar N; 15 g m-2 of N in soil with foliar N (1% urea in 200 L ha-1) and 30 g m-2 of N in soil with foliar N combined with glyphosate doses (0, 200, 400 and 600 g ha-1 active ingredient (a.i.)). The N doses were split into five applications along the year. The following variables were evaluated: height, leaf chlorophyll index and foliar accumulation of nitrogen, phosphorus and potassium. Fertilization with 15 g m-2 of N in soil without foliar N application, split into five times along the year, was adequate for the turfgrass, while foliar fertilization did not promote benefits. The glyphosate dose of 400 g ha-1 a.i. was effective in reducing the growth of Esmeralda grass, without compromising its color and promoted less N, P and K accumulation in the leaves, reducing the height and dry matter production.

Biological nitrogen fixation efficiency can be increased by co-inoculation with Bradyrhizobium spp. and Azospirillum brasilense, allowing even greater uptake of water and nutrients, leading to higher yields and enabling the insertion of unusual crops, such as cowpea (Vigna unguiculata L. Walp.), in the agricultural production system in the Cerrado region of Brazil. Thus, this study aimed to evaluate the technical and economic viability of cowpea in the Cerrado region, as a function of N doses and co-inoculation of seeds with Azospirillum brasilense and Bradyrhizobium. The study was carried out in a no-tillage system in Selvíria, MS, Brazil. The experimental design was a randomized block design, with four repetitions, arranged in a 3 x 5 factorial scheme, corresponding to three types of inoculation (without inoculation - control, with two strains of Bradyrhizobium spp. SEMIA 6462 and SEMIA 6463 - the conventional inoculation of cowpea, and these two strains of Bradyrhizobium spp. plus A. brasilense strains Ab-V5 and Ab-V6); and five N doses (0, 20, 40, 80 and 160 kg ha-1), as urea, applied as topdressing. The following evaluations were performed: grain yield, total operating cost, effective operating cost, gross revenue, operating profit, profitability index, equilibrium price and equilibrium yield. Co-inoculation with A. brasilense increases cowpea grain yield, which makes cowpea production in the Cerrado region of Brazil technically and economically viable, without the need to apply N fertilizers in topdressing.

Boron is one of the most limiting micronutrients in the grain production system in Brazil. Thus, the objective of this study was to evaluate the effects of the application forms and doses of boron on the concentration of this nutrient in the leaves, straw, and grains of wheat, as well as the production components and grain yield. The residual effect of boron in the soil was also evaluated. An experiment was conducted in a no-tillage system in Oxisol with clay texture in Selvíria, Mato Grosso do Sul. The experimental design was a randomized block design with four replicates arranged in a 4 x 3 factorial scheme. Four doses of boron (0, 1, 2, and 4 kg ha-1) were applied with a boric acid source (B = 17%) and three application forms: a) during the desiccation of the predecessor straw with herbicide; b) at the time of sowing in soil along with formulated fertilization seeding, and c) via the leaves with the application of post-emergent herbicide. The application of boron to the soil at the time of sowing at an approximate dose of 2 kg ha-1 provides the highest number of spikelets per ear and wheat grain yield.

Brazilian Cerrado soils are commonly deficient in boron (B) and zinc (Zn). It is still debated whether B and Zn interaction has a synergistic or antagonistic effect on the absorption thereof. Thus, we conducted this study to evaluate the effect of boron rates (0, 1, 2, 3, and 4 kg ha?1, as boric acid), with or without zinc fertilization (2 kg ha?1 Zn, as zinc sulfate), on corn nutritional status and grain yield. We also assessed the residual effect of such fertilization on the fall corn crop grown on an Oxisol in a no-tillage system. A synergistic effect between B and Zn was observed on corn nutritional status when applied to the soil at rates of up to 2 kg ha?1, with higher soil contents resulting from the interaction between these micronutrients. Zinc fertilization and increasing boron rates had no significant influence on corn grain yield in both spring/summer and fall crops, grown on a boron-deficient, clayey soil of Cerrado biome.

O objetivo do presente trabalho foi avaliar as correlações entre produtividade e resposta à seca (RS) do eucalipto entre os atributos do solo em dois tipos climáticos distintos no Brasil. Para isto, foram instalados 24 experimentos no Brasil com 4 clones comuns em todos os experimentos para obter fortes contrastes edafoclimáticos, e, desse modo, mensurar a produtividade e a reposta à seca e descrever as suas relações com os atributos de solos. Foram avaliados dois grupos climáticos: Úmido (relação precipitação: evapotranspiração entre 1,0 a 2,5) e Subúmido (relação precipitação: evapotranspiração entre 0,5 a 1,0). Os atributos dos solos avaliados foram: Areia, Silte, Argila, matéria orgânica (M.O.), capacidade de troca catiônica (CTC). Para os sítios localizados na classe climática Úmida, o VCCC correlacionouse negativamente com a M.O. e argila, e positivamente com a Areia. Para a RS, as correlações foram observadas para clima Subúmido para as variáveis CTC e Areia, e para o clima Úmido, não foram observadas correlações entre os atributos de solos com a RS.

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Crop rotation associated with the use of cover crops promotes the introduction of crop residues to the soil, with direct and indirect effects on the availability of plant nutrients, especially nitrogen (N). The objectives of this study were to estimate the N utilization from 15N-urea and cover crop residues (labelled with 15N) of maize crops grown in succession, and evaluate the effects of the isolated and combined use of cover crops and urea on maize plant height, yield components, and grain yield, grown under a no-tillage system. Field research was conducted in an Oxisol (Rhodic Haplustox), Cerrado (Savannah) phase. The experimental design was a randomized block with 20 treatments and four replications in a 5x4 factorial scheme. The treatments were four cover crops species: sunn hemp (Crotalaria juncea L.), pigeon pea (Cajanus cajan (L.) Millsp), green velvet bean (Mucuna prurens), and millet (Pennisetum glaucum L.) + spontaneous vegetation (fallow in the off-season), combined with four N rates: 0, 30, 90, and 150 kg ha-1, applied at the sowing and topdressing stages. The results showed that legume cover crops provided maize grain yields equivalent to the application of 80-108 kg ha-1 N as urea. The urea N utilization by the maize was at an average of 43.5 % of the applied amount. The results indicate that cover crops, particularly legume cover crops, are an important source of N to non-legume cereals. Legumes used as cover crops can replace nitrogen fertilizers of more than 80 kg ha, which is both environmentally and economically viable for corn production.