AbstractUsing soil cover residues from previous crops through integrated systems has proven effective in driving changes in soil properties with nutrient cycling, promoting higher grain production. However, there is still a need to investigate the changes that different cultivation arrangements of these management systems can influence on soybean productivity. The aim was to compare conventional soybean cultivation methods with integrated systems in a tropical region over 2 years and how these systems affect desiccation efficiency, biomass decomposition, carbon/nitrogen ratio, nutrient cycling, as well as soybean productivity. An experimental area, under a block design with three replications, with conventional soybean cultivation system with soybean cultivated over crop residues produced by a previous integration of maize, three cultivars of Panicum maximum (Tamani, Quenia, and Zuri guinea grasses), and pigeon pea, arranged in monoculture and triple intercropping, it was implemented in Latossolo Vermelho Acriférrico typical, Goiás, Brazil. The results indicated that Tamani and Quenia guinea grasses, along with pigeon pea, exhibited higher desiccation efficiency in both monoculture and intercropping. The previous integration of maize with Panicum cultivars and pigeon pea increased soil coverage and maximized nutrient cycling, resulting in increasing productivity gains by approximately 39.8% compared to soybean cultivation without biomass covering the soil. These results highlight the importance of considering nutrient cycling and decomposition rates in fertilization strategies to increase the sustainability of systems. Therefore, integrated systems, which combine grasses and legumes, represent a promising and efficient strategy for agricultural production systems.
The impact of anthropogenic climate change is affecting both natural and managed ecosystems. Climate variables that interact with each other (e.g., temperature, water availability, atmospheric CO2 levels), potentially affecting nutrient uptake and crop productivity that could causing yield losses with serious consequences for worldwide food availability. As a beneficial element, silicon (Si) is the second most abundant element in the Earths crust; however, it is often not readily available for plant uptake. Therefore, Si fertilization may be necessary in weathered soils, especially for Si-accumulating plants such as sugarcane. The majority of studies on plant ecological stoichiometry focus on elemental C, N and P contents, ratios, and relationships within and across plant organs in a changing world. Although several studies have reported that Si application could stimulate plant growth and mitigate multiple stresses, the effects of Si on carbon immobilization, 708nutrients uptake, and the C:N:P:Si stoichiometry into sugarcane plant remain poorly understood. This chapter highlights our current understanding on the main mechanisms of silicon-alleviates abiotic stress in plants, their ability on nutrient uptake, nutrient accumulation, nutrient use efficiency, C:N:P:Si stoichiometry, as well as physiological and productive parameters of sugarcane in terrestrial agroecosystems. The major points are the following: (1) silicon addition on C:N:P:Si stoichiometry, nutritional efficiency, and plant growth of sugarcane under different water availability and (2) Si supplied via nutrient solution, foliar or fertirrigation on nutritional imbalance, antioxidant defense system, and physiological and biochemical mechanisms of sugarcane
La creciente demanda mundial de alimentos, impulsada por el aumento sostenido de la población humana, exige una producción agrícola eficiente y sostenible. En este contexto, los fertilizantes químicos han sido ampliamente utilizados para aumentar la productividad, aunque muchas veces en dosis excesivas. Este uso intensivo ha generado impactos negativos, como la emisión de gases de efecto invernadero (particularmente óxido nitroso, N₂O), la lixiviación de nutrientes y la contaminación de acuíferos. Además, los fertilizantes representan un costo considerable, afectando la sostenibilidad económica a mediano y largo plazo. El sector agrícola enfrenta presiones adicionales derivadas del cambio climático, como el aumento de temperaturas, la sequía, la toxicidad por metales pesados y desequilibrios nutricionales, los cuales afectan la calidad y el rendimiento de los cultivos. En particular, la región de OHiggins es una de las principales zonas productoras de maíz en Chile y enfrenta desafíos derivados del uso excesivo de fertilizantes nitrogenados, lo que no solo eleva los costos productivos, sino que también compromete la salud medioambiental. Este proyecto tiene como objetivo principal evaluar el impacto de la aplicación de silicio (Si) sobre el equilibrio nutricional y los parámetros productivos de plantas de maíz cultivadas bajo condiciones de exceso de nitrógeno. La hipótesis central es que el silicio puede mejorar la homeostasis estequiométrica elemental C:N:P, reducir los efectos negativos del exceso de nitrógeno y promover una mayor eficiencia en el uso de fertilizantes. Se propone además evaluar el potencial de reducción en el uso de fertilizantes nitrogenados mediante la optimización de su aplicación, sin comprometer la productividad. Se espera que los resultados de esta investigación contribuyan al desarrollo de estrategias más sostenibles, resilientes y eficientes para la producción de maíz en la región OHiggins y más allá.
A presente proposta é um projeto de inovação no Brasil e tem como premissa/meta de mostrar que é possível diminuir N-fertilizante com o emprego de A. brasilense, como alternativa de FBN na tentativa de diminuir a fertilização química, os altos custos de N-fertilizantes e consequentemente as deposições de Nr nos ecossistemas, assim como melhorar a eficiência do uso da água a partir do emprego da fertirrigação com Si estabelecendo pela primeira vez as doses viáveis agronomicamente, zootecnicamente e economicamente para o cultivo irrigado do milho safrinha e, na produção de silagens na nutrição animal. Assim, será avaliado os efeitos aditivos ou não, de diferentes doses de Si via fertirrigação e da inoculação ou não com A. brasiliense sobre: O acúmulo e a eficiência de utilização dos nutrientes, em função do estádio de desenvolvimento das plantas do milho; A estequiometria (relações C:N:P:Si) e, o crescimento vegetativo do milho safrinha e/ou sorgo e/ou milheto; Os processos fisiológicos: taxa fotossintética, índice de cor verde, condutância estomática, taxa de transpiração e eficiência de uso da água do milho e/ou sorgo e/ou milheto em estudo; As características morfogênicas e estruturais, a dinâmica de crescimento, a produção e quantificação de biomassa aérea, a composição químico-bromatológica da biomassa, a produção e sanidade dos grãos, o índice de colheita de grãos e a eficiência agronômica do milho e/ou sorgo e/ou milheto; Além de avaliar o perfil fermentativo, a estabilidade aeróbia, a composição química e a digestibilidade in vitro das silagens na forma tradicional e, na forma de ração total para dietas de bovinos de corte e/ou cabras leiteiras
Background: Understanding canopy light interception is essential for optimizing forage production and improving the efficiency of grazing systems. Accurate quantification of photosynthetically active radiation (PAR) intercepted by the canopy allows for better estimation of crop coefficients and growth dynamics. This study aimed to assess the forage mass and nutritional value of Guinea grass pastures managed under two grazing frequencies, defined by 90% and 95% light interception (LI) measured using AccuPar equipment, and two post-grazing stubble heights (30 and 50 cm). Evaluations were conducted during both the rainy season and a dry year to capture seasonal variability in pasture performance. Methods: The experimental design was of completely randomized blocks with four replications. Results: The treatment whit 90% LI resulted in higher values of crude protein and digestible. However, 95% LI resulted in higher values of neutral detergent insoluble nitrogen and acid detergent insoluble nitrogen values in grass pastures Guinea. The highest value of forage mass in Guinea grass was reported with 95% LI in association with a post-grazing height of 30 cm. Conclusions: Management of light interception at 90% provided a reduced amount of forage with better nutritional value. Pasture management considering the light interception technology with the AccuPar equipment was efficient as a pattern for interrupting pasture regrowth in the vegetative phase.