Analysis of the photosynthetic performance of Brachiaria brizantha cv. Marandu pastures inoculated with Azospirillum brasilense and Pseudomonas fluorescens under heated atmosphere under field conditions

• Grant number: 24/17046-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2025
• End date: December 31, 2025
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Carlos Alberto Martinez y Huaman
• Grantee: Maria Luiza Pereira Andrade
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 22/15021-2 - Physiological and productive performance of forages Brachiaria brizantha cv Marandu and the hybrid Brachiaria Mavuno inoculated with Azospirillum brasilense and subjected to warming in a future climate simulation experiment, AP.PFPMCG.R

Abstract

With the increased frequency and intensity of extreme weather events caused by global climate change, there is an urgent need to adopt mitigation and adaptation measures that allow for the reduction of greenhouse gas emissions into the atmosphere, and adaptation, with measures that allow for the alleviation of the suffering of all living beings impacted by the consequences of events such as droughts, floods and heat waves. Agricultural activity is one of the main contributors to global warming, even though this activity is directly dependent on the climate for production, since the increase in temperature is one of the abiotic factors that affects most of the physiological processes of plants. Brachiarias are widely used in pastures in Brazil and adapt to the most varied soil and climate conditions. The extractive form of livestock farming has been increasing the degraded areas of pasture or in the process of degradation, leading to losses in productivity and the stock of Carbon (C) in this soil due to inappropriate management, which contributes significantly to the increase in greenhouse gas emissions and consequently in global temperature. The temperature rise predicted for the coming decades has the potential to impact the effects of inoculation with bacteria that promote plant growth. Therefore, this research project aims to understand how an increase in temperature of +2°C under field conditions affects the photosynthetic performance and biomass production of the forage grass Brachiaria brizantha cv. Marandu inoculated or not with strains of the nitrogen-fixing bacterium Azospirillum brasilense together with Pseudomonas fluorescens. This study hypothesizes that inoculation will mitigate the deleterious effects of increased temperature on the photosynthetic performance and productivity of Marandu grass.