Impact of cover crops on soil health: microbial diversity and phosphorus dynamics in sustainable agricultural systems

• Grant number: 24/17838-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: March 01, 2025
• End date: February 29, 2028
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Lucas William Mendes
• Grantee: Luana do Nascimento Silva Barbosa
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 21/10573-4 - Center for Carbon Research in Tropical Agriculture (CCARBON), AP.CEPID

Abstract

In agricultural areas, the soil microbial community is increasingly recognized as a crucial factor in phosphorus (P) dynamics. Additionally, the carbon residues from cover crops are key factors in modulating the chemical, physical, and biological processes of the soil, mitigating the effects of climate change, and altering soil health and tropical agricultural sustainability. However, the impact of the microbial legacy (soil-plant feedback) left by these plants is still underexplored, as are the interactions between plants and microorganisms in the soil that can influence P availability for commercial crops and soil ecosystem services. This project aims to determine how cover crops promote changes in P cycling processes, microbiota, and soil ecosystem services through complementary studies. To achieve this, two short- and long-term field experiments and a controlled environment pot experiment will be evaluated. The first study intends to investigate the contribution of cover crops to agricultural sustainability, focusing on soil carbon reservoirs and their effects on soil health and multifunctionality. More specifically, the second study will focus on the microbial feedback (soil-plant) left by cover crops in the soil for a commercial crop, assessing how cover crops modulate networks of microbial communities and genes related to the P cycle, such as pqqC and phoC, to increase P availability. The third study will describe how cover crops in association with arbuscular mycorrhizal fungi can impact P dynamics in the soil, altering P reservoirs in direct-seeding agricultural systems managed with these plants in both the short and long term. Additionally, to be conducted during an internship abroad, the greenhouse experiment will analyze microbial recruitment in the rhizosphere of cover crops through the exudation of metabolites under high and low P limitation conditions. This project is expected to provide insights to expand our knowledge of the effect of cover crops on soil microbiome modulation and P dynamics, offering support for the development of techniques for more sustainable ecosystem use.