Copper (Cu) is a critical micronutrient for wheat (Triticum aestivum L.), essential for growth and grain baking quality, yet its availability is limited because Cu is specifically adsorbed on colloids of highly weathered tropical soils like Oxisols. This study hypothesizes that Cu-doped biochar composites can outperform traditional Cu fertilizers in improving wheat growth and Cu use efficiency. Composites were synthesized from chicken manure (FCM), shrimp shells (FSC), and sewage sludge (FSS), doped with copper sulfate (CuSO₄5H₂O) or copper oxide (CuO), and pyrolyzed at 300 °C or 550 °C. The experimental design involved greenhouse trials in two Oxisols (RYL and DRL), assessing Cu release kinetics, plant Cu uptake, and dry matter production. Fourier Transform Infrared Spectroscopy (FTIR) confirmed successful Cu integration. Results revealed that CSS/CS-5 (FSS + CuSO₄5H₂O at 550 °C) improved Cu uptake and shoot biomass in DRL soil, while CSC/CS-3 (FSC + CuSO₄5H₂O at 300 °C) enhanced wheat CuSO₄5H₂O growth in RYL soil. Peak Cu availability varied by CuSO₄5H₂O soil and composite type, with residual Cu highest CuSO₄5H₂O in CuSO₄5H₂O-treated soils. These findings demonstrate that Cu–biochar composites, tailored to soil conditions, offer a sustainable alternative to mineral Cu fertilizers by enhancing the nutrient availability and wheat grain yield.

The cover crops can reduce soil exposure and erosion while enhancing nutrient cycling for crops. Effective implementation requires understanding how cover crops decompose and release nutrients to align with crop demand. This research assessed the decomposition rates and nutrient release of various legume residues commonly used as green manure or cover crops in agricultural systems. The study took place in a nutrient-deficient Red-Yellow Ultisol, using a split-plot design with different legume cover crop species: Crotalaria juncea, Crotalaria spectabilis, Cajanus cajan, Cajanus cajan (L.) Millsp), Dolichos lablab, Canavalia ensiformis and Mucuna aterrima as the main plots and six evaluation periods: 0, 30, 60, 90, 120, and 150 days after incorporation (DAI) as the subplots. Initial mass losses were observed in the first 60 days, followed by a slower decline over the study period. The order of nutrient accumulation in biomass was found to be: K > N > P > Ca > Mg. The Dolichos lablab species had the slowest decomposition rate, with a half-life of 43 days, while Cajanus cajan had the fastest, with a half-life of 65 days. Potassium reached its maximum by 30 DAI, indicating a rapid transfer to the soil. Nitrogen, P, and K contents decreased during different vegetative phases, highlighting the importance of proper timing for legume management. Hemp, Crotalaria spectabilis, Dolichos lablab, and Canavalia ensiformis were suitable for short-cycle vegetables due to rapid nutrient availability. Conversely, Cajanus spp., and Mucuna aterrima were better for extended soil coverage and slow nutrient release.

: As deficiências nutricionais causam perdas econômicas e dentre estas a deficiência de boro (B) pode ser a causa de um sintoma em bagas da videira. Este sintoma é a extrusão da semente da uva de sua baga com posterior cicatrização da epiderme. Diante do exposto, este experimento objetivou avaliar o controle da extrusão da semente da baga, Niágara Rosada, através da aplicação doses de B. O fertilizante comercial utilizado foi o Bórax, que possui 11% de B. Conduziu-se o experimento em Santa Teresa-ES. Realizaram-se as aplicações de B via solo, diretamente abaixo da copa da videira. Utilizou-se o delineamento experimental em blocos casualizados, em vinhedo com 8 anos de idade. Foram utilizadas quatro doses de bórax em três blocos, utilizando duas plantas por unidade experimental, totalizando 24 unidades experimentais. As doses de bórax foram 0; 5; 10 e 20 g por planta por aplicação, onde a primeira foi adicionada imediatamente após a poda de inverno e a segunda foi aplicada no início do florescimento, totalizando assim as doses: 0; 10; 20; e 40 gramas por planta por ciclo produtivo. Ao longo da produção da videira, foi realizada a coleta de folhas para análise química e foram contabilizados o número de bagas rachadas pela deficiência culminando na extrusão da semente. Houve controle do sintoma e recomenda-se a aplicação de B imediatamente após a poda de inverno e no início do florescimento.