Silicon (Si) has been extensively studied for its ability to decrease sodium (NaCl) toxicity in various plant species. Nonetheless, the processes that drive these responses are still not well understood. In this study, we investigate the effects of silicon (Si) on the modification of hydrogen peroxide concentration [H2O2], photosynthetic pigment content, nutrient accumulation, and the production of root and shoot dry biomass in sunflower (Helianthus annuus L.) plants hydroponically grown with NaCl (0 and 100 mM) in combination with Si (0 and 2.0 mM). Salt stress induced a significant decrease in plant growth due to high [H2O2] and a decrease in photosynthetic pigment content and nutritional status, denoting that there is oxidative and ionic stress. Nevertheless, Si addition to the growth medium consistently decreased the [H2O2] in sunflower and photosynthetic pigment content, and macro- and micronutrient accumulation, which was associated with an increase in root and shoot dry matter production. These findings indicate that adding Si to the growth medium is crucial for enhancing plant resistance to salt-induced ionic and osmotic stress, making it a promising strategy for improving crop growth and management under salinity conditions.

Uma “Visão Holística na Relação Solo-Planta-Animal-Ambiente” aborda a interconexão e a interdependência dos componentes naturais em sistemas agroecológicos e ambientais. Em um curso de pós-graduação, essa abordagem holística é
explorada para compreender como o solo, as plantas, os animais e o ambiente interagem de maneira complexa, afetando a sustentabilidade e a produtividade dos ecossistemas agrícolas e naturais. A relação entre esses elementos é fundamental para promover
práticas agrícolas sustentáveis que preservem a saúde do solo, otimizem o uso de recursos naturais, aumentem a biodiversidade e melhorem a resiliência dos sistemas agrícolas frente às mudanças climáticas. Esse conhecimento integra conhecimentos sobre
fertilidade do solo, manejo de culturas, nutrição vegetal e animal, conservação ambiental e impacto das práticas humanas, enfatizando a necessidade de uma gestão integrada que considere todos esses fatores para alcançar um equilíbrio ecológico, econômico e social.
A compreensão desses processos interligados é essencial para promover a segurança alimentar, a saúde ambiental e o bem-estar animal, buscando soluções inovadoras para os desafios globais, como a degradação do solo, a perda de biodiversidade e a escassez de
recursos naturais.

El constante aumento de la población humana exige una producción de alimentos que sea rápida y sostenible. Debido a esto, los fertilizantes químicos se han utilizado extensamente, a menudo en exceso, lo que genera múltiples problemas. Esto hace que la sostenibilidad agrícola a mediano y largo plazo dependa de la implementación de alternativas más accesibles y ecológicamente seguras. La productividad agrícola mundial se enfrenta a dificultades debido a tensiones humanas, abióticas y ambientales causadas por el cambio climático. Este proyecto busca resolver estos desafíos mediante el estudio de estrategias sostenibles para mejorar la eficiencia en la producción de maíz en el centro-sur de Chile. El proyecto propone evaluar el impacto de estas estrategias en la absorción y removilización de nutrientes, la sanidad vegetal, así como en el rendimiento y calidad del maíz. En Chile, el maíz desempeña un papel vital en la agricultura, tanto en la alimentación humana como animal. Se prevé que los resultados de esta investigación impulsen una producción de maíz más sostenible y resistente ante los retos ambientales y económicos actuales en la región centro-sur de Chile.

Stoichiometric homeostasis in plants and mechanisms for resisting biotic and abiotic stresses are very active research areas. This book chapter delves into the multifaceted role of silicon, exploring how it promotes sustainability in plant production by improving C:N:P stoichiometry and nutrient use efficiency by plants under many stress conditions. It examines the interplay between silicon and the homeostasis of carbon (C), nitrogen (N), and phosphorus (P) in plants. It underscores the importance of maintaining plant C:N:P homeostasis in mitigating stress induced by climate change, emphasizing silicon’s potential in bolstering plant resilience amid changing environmental conditions. Furthermore, it examines how maintaining the balance of plant C:N:P homeostasis alleviates stress caused by nutritional imbalances or toxicities, emphasizing the importance of balanced nutrient levels for optimal plant health and productivity. Lastly, the chapter outlines future perspectives and research avenues, underscoring the ongoing necessity to investigate the complex mechanisms that govern nutrient homeostasis and their implications for sustainable agriculture amid changing climatic conditions

The increase in pineapple production has generated a large amount of waste, which, when incorporated into the soil, can lead to contamination and environmental degradation. In this context, this study highlights the innovative combination of pineapple waste and Leucaena hay, offering benefits for animal nutrition while reducing input costs. The objective of this study was to determine the nutritional value of silage from ‘Pérola’ pineapple waste (PS) with different levels of Leucaena hay. A completely randomized design was adopted with six treatments (pre-wilted PS and PS with 0%, 10%, 20%, 30%, and 40% inclusion of Leucaena hay (LH)). The dry matter content of the silage, crude protein, lignin, and pH increased linearly (p < 0.05) as a function of the inclusion of Leucaena hay, while buffering capacity, soluble carbohydrate content, and effluent losses showed an inverse relationship. As LH levels increased, ruminal DM disappearance decreased. Wilting the pineapple plant did not alter the in vitro gas production, in vitro digestibility of organic matter, partition factor (PF), and methane production when compared to the silages added with Leucaena hay. It is recommended to add 20% Leucaena hay in PS silage.

Low doses of glyphosate from application drift can be phytotoxic or stimulate growth of glyphosate-susceptible crops. The application of Si can prevent herbicide-caused plant stress. The effects of Si application (3 mM Si) on low doses (0, 36, 72, and 180 g a.e. ha-1) of glyphosate were determined on Sorghum bicolor in a greenhouse study. Growth parameters, mineral content, metabolite content, and glyphosate and aminomethylphosphonic acid (AMPA) content were measured. Increasing glyphosate content, but no AMPA, was found with increasing glyphosate application rates. Shoot dry weight was increased by 72 g ha-1 of glyphosate when pretreated with Si, and plant height increased in Si-treated plants treated with 72 g ha-1 of glyphosate. Si alone had no effects on growth. Shikimate content was increased by the highest glyphosate rate. Phenylalanine content was generally increased by all glyphosate treatments with or without Si, except for 72 g ha-1 glyphosate without Si. Tyrosine content was increased by 36 and 180 g ha-1 glyphosate without Si. Caffeate content was decreased by Si in the control, and ferulate content was increased with 180 g ha-1 glyphosate in Si-treated plants. Ca levels were reduced by Si at 180 g ha-1 glyphosate. Mn levels were lower than those of the control without Si for all other treatments with Si. The increases in shikimate with the highest glyphosate dose indicated that the herbicide reached its herbicide target and should be causing stress, but the only growth effect was the stimulation of some growth parameters at 72 g ha-1 of glyphosate with Si pretreatment. Similarly, there were increases in some metabolites at some glyphosate concentrations with or without Si. Our results indicate that the rates that we used cause little stress and that Si pretreatment could potentiate glyphosate hormesis for some parameters.

Nitrogen (N) holds a prominent position in the metabolic system of plants, as it is a main constituent of amino acids, which are the basic building blocks of proteins and enzymes. Plants primarily absorb N in the form of ammonium (NH4+) and nitrate (NO3-). However, most plants exhibit severe toxicity symptoms when exposed to NH4+ as the sole N source. Addressing NH4+ stress requires effective strategies, and the use of silicon (Si) has shown promising results. However, there is a lack of underlying studies on the impact of NH4+ toxicity on C:N:P stoichiometric balance and the role of Si in these ratios. In this study, we explored the effects of varying NH4+ concentrations (1, 7.5, 15, 22.5, and 30 mmol L-1) on the C:N:P stoichiometry and yield of beetroot in hydroponic conditions. Additionally, we investigated whether the application of Si (2 mmol L-1) could mitigate the detrimental effects caused by toxic NH4+ levels. The experiment followed a randomized block design based on a 5 × 2 factorial scheme with four replicates. Results revealed that in the presence of Si, both [N] and [P] significantly increased in shoots and roots, peaking at 15 mmol L-1 of NH4+ in the nutrient solution. While shoot [C] remained stable, root [C] increased with NH4+ concentrations of 22.5 and 30 mmol L-1, respectively. Moreover, shoot and root [Si] increased with higher NH4+ levels in the nutrient solution. The findings underscored homeostatic instability under the highest NH4+ levels, particularly in plants cultivated without Si in the nutritive solution, leading to a reduction in both shoot and root dry matter production.

O plano de desenvolvimento institucional do Estado de Goiás prioriza a internacionalização da pesquisa e dos pesquisadores. A estratégia envolve integrar a ciência produzida em Goiás em redes de cooperação internacionais, promovendo colaborações que enriquecem o conhecimento e impulsionam a inovação. Nesse contexto, a visita do pesquisador internacional Dilier Olivera Viciedo da UOH, Chile em colaboracão com a pesquisadora Kátia Aparecida de Pinho Costa do IF-Goiano, Brasil fortalecerá os vínculos entre os pesquisadores, além de contribuir para a internacionalização dos programas de pós-graduação. A proposta em questão, na qual já há colaboração com o pesquisador, visa enfrentar desafios das mudanças climáticas através da adaptação e mitigação, estudando o desempenho de gramíneas forrageiras sob aquecimento e inoculação bacteriana, contribuindo para a agricultura sustentável e a redução de emissões de gases de efeito estufa. Durante sua estadia, o Prof. Dilier também buscará aprimorar metodologias de avaliação de forragem para promover a sustentabilidade no manejo de pastagens.