Entomopathogenic fungi for enhanced soil nitrogen retention and crop protection

Overview

This research investigates whether entomopathogenic fungi—specifically Metarhizium and Beauveria—can retain nitrogen in soil and deliver it to plant roots as effectively as, or better than, traditional mycorrhizal fungi. These fungi are well-known insect pathogens but also naturally colonize plant roots and the rhizosphere, where they may mobilize nitrogen from insect biomass in exchange for plant carbon. The goal is to determine whether these dual-function fungi can simultaneously reduce nitrate leaching losses and protect crops from insect damage, offering a single biological solution that addresses two major agricultural challenges.

Technical specifications

Research approach:

• Four fungal treatments will be compared: Metarhizium, Beauveria, and two arbuscular mycorrhizal (AM) fungi, plus combination treatments
• Four test crops representing diverse agricultural systems: soybean, haricot bean, switchgrass, and tomato
• Soil nitrogen treatments at low, optimum, and high nitrate levels to simulate varying fertilizer regimes
• Each treatment includes 8–10 pots with three technical replicates, repeated three times
• Soil nitrate measured weekly over an 8-week time course using a Horiba Laqua NO3 ion meter

Key advantages over mycorrhizal-only approaches:

• Metarhizium and Beauveria are already produced at industrial scale with established formulation and stability
• Easy application across a wide range of crops
• Dual functionality: nitrogen retention plus insect pest protection
• Potential to reduce dependence on both chemical fertilizers and chemical insecticides

Technology readiness level

This is an early-stage research project (TRL 2–3) focused on comparative laboratory validation. The fungi themselves are already commercially produced and widely deployed as biocontrol agents, but their specific capacity for nitrogen retention and interaction with mycorrhizal fungi has not been characterized. Successful results would establish proof-of-concept data to support subsequent greenhouse and field-scale trials, with potential downstream applications in biofertilizer and biopesticide product development for sustainable agriculture.