The present study had the objective to evaluate the effect of blends of KCl and K₂SO₄ fertilizers and their influence on the yield and the nutritional state of coffee plants, as well as on the chemical composition and quality of the coffee beverage. The experimental design was in randomized blocks with four repetitions and six treatments (T1: 100% KCl; T2: 75% KCl + 25% K₂SO₄; T3: 50% KCl + 50% K₂SO₄; T4: 25% KCl + 75% K₂SO₄; T5: 100% K₂SO₄; and a control, without application of K). The following analyses were performed: K and Cl content in the leaves and the soil, stocks of Cl in soil, yield, removal of K and Cl with the beans, cup quality of the beverage, polyphenol oxidase activity (PPO), electric conductivity (EC), potassium leaching (KL), the content of phenolic compounds, the content of total sugars (TS), and total titratable acidity (TTA). The stocks of Cl in the soil decreased as the proportion of KCl in the fertilizer was reduced. The fertilization with KCl reduces the cup quality and the activity of the polyphenol oxidase, probably due to the ion Cl. The increase in the application of Cl directly relates to the increase in potassium leaching, electric conductivity, and titratable acidity. Indirectly, these variables indicate damages to the cells by the use of Cl in the fertilizer. The activity of the polyphenol oxidase enzyme and the cup quality indicate that the ion Cl- reduces the quality of the coffee beverage. K content in the leaves was not influenced by the application of blends of K fertilizer while Cl content increased linearly with KCl applied. The application of KCl and K₂SO₄ blends influenced coffee yield and the optimum proportion was 25% of KCl and 75% of K₂SO₄. The highest score in the cup quality test was observed with 100% K₂SO₄.

Selenium (Se) is an essential element for humans. However, much of the world’s human population is deficient in this element, which has become a public health problem. This study aimed to evaluate whether applying severe water stress to wheat plants (Triticum aestivum L.) could allow Se to reduce the production losses and increase the grain quality, thereby contributing to the reduction in hidden hunger. The experiment was conducted in a randomized block design with four replications in a 5 × 2 factorial scheme, with five doses of Se (0.00, 0.25, 0.50, 1.00, and 2.00 mg dm⁻³) and two irrigation conditions (with and without water deficit). When sodium selenate (Na₂SeO₄) was applied to the soil, the grains were rich in Se. Under low doses, there was an enrichment of the grains in sulfur, iron, copper, and zinc as well as total free amino acids and total soluble proteins, and lower losses in productivity under severe water stress. Higher doses decreased the concentration of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), increased the catalase activity, and increased the water use efficiency (WUE). Therefore, applying Se at a dose of 0.25 mg dm⁻³ is effective for the biofortification of wheat grains. It enhances grain nutritional quality, increases Se bioaccessibility, and reduces production losses under water stress conditions.

O objetivo deste estudo foi determinar os teores de elementos-traço em solos de planícies de inundação e em sedimentos de fundo de rios para identificar áreas contaminadas por esses elementos comparando os teores obtidos em locais com e sem interferência antrópica. Foram amostradas águas superficiais, sedimentos e solos em 80 locais na Bacia do Rio das Mortes, em Minas Gerais, para determinação de Cd, Cu, Cr, Ni, Pb, Mn e Zn. Das 80 amostras, 40 localizavam-se em locais suspeitos de contaminação e 40 em locais-controle, denominados “locais naturais”. Os resultados mostraram que, na Bacia do Rio das Mortes, a agricultura não constitui um fator relevante de incremento dos elementos-traço estudados. Porém, verifica-se grande influência de centros urbanos, industrializados ou não, na dispersão de elementos-traço para o ambiente. Foi verificada contaminação nos solos das planícies de inundação por Pb nos Municípios de Dores de Campos e Prados, Cu, Cr, Ni, Pb e Mn em Nazareno e São Tiago, Cr e Ni em São João Del Rei e Cu em Barbacena.

Desorption electrospray ionization mass spectrometry imaging (DESI-MSI) was used to investigate the spatial distribution of arsenic species in leaves of Pteris vittata, a fern known for its exceptional capacity for arsenic hyperaccumulation. Leaf imprints were prepared by pressing fresh fern leaves onto polytetrafluoroethylene (PTFE) sheets for DESI-MSI analysis. Liquid chromatography coupled with inductively coupled plasma mass spectrometry (LC-ICP-MS) analysis of naturally contaminated leaves revealed high concentrations of inorganic arsenic species, i.e., arsenite and arsenate. In negative-ion mode, DESI-MSI detected arsenite, mainly along the margins of these naturally contaminated leaves. Although LC-ICP-MS detected arsenate, DESI‑MSI produced only weak arsenate signals, likely owing to limited desorption and ion suppression. To evaluate the uptake and distribution of organic arsenic species, leaves collected from an area without known arsenic contamination were exposed to solutions of dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) for 24 h. DESI-MSI revealed that both organic arsenic species were readily absorbed, translocated throughout the leaves, and preferentially accumulated in the central region. These findings show that DESI-MSI is a rapid, effective approach for visualizing the spatial distribution of arsenic species in Pteris vittata leaves, providing valuable insights into arsenic uptake and transport mechanisms with potential applications in plant physiology, environmental monitoring, and phytoremediation research.