Assessment of the potential of secondary Caatinga soils in promoting soybean growth under water stress and isolation of rhizosphere growth-promoting microorganisms.

• Grant number: 25/08618-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2025
• End date: September 30, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Fernando Dini Andreote
• Grantee: Ryan Gustavo Souza da Cunha
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The Caatinga is a biome characterized by extreme climatic conditions, particularly water scarcity. Microorganisms adapted to this arid environment may represent a promising source for promoting the growth of agricultural crops under water stress. This project aims to investigate the potential of soils from secondary Caatinga-areas under fallow management for 24 years and undergoing natural regeneration-in modulating the soybean (Glycine max) rhizosphere and enhancing its growth under drought conditions. To this end, different proportions (1%, 5%, 10%, and 20%) of Caatinga soil will be mixed with Atlantic Forest soil, in addition to two controls (100% of each soil), totaling six treatments. The experiment will be conducted in a completely randomized design, in a 6 × 2 factorial scheme (soil proportions × irrigation levels: control and water stress), with seven replicates per treatment, amounting to 84 pots. Agronomic and physiological parameters of soybean will be evaluated, along with the isolation of growth-promoting rhizobacteria adapted to drought conditions. This study will contribute to the bioprospecting of drought-adapted bacteria, with potential application in sustainable agricultural strategies aimed at mitigating the effects of water stress, such as bioinputs, especially in light of the increasing occurrence of extreme climate events.