Exploring microplastic interactions in agricultural soils: effects on the soil-plant-insect system

• Grant number: 25/05768-1
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: August 01, 2025
• End date: July 31, 2028
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Cassiana Carolina Montagner
• Grantee: Isabela Carreira Constantino
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 22/12104-4 - Fate and impacts of microplastics and pesticides in aquatic and terrestrial matrices in agricultural contexts, AP.TEM

Abstract

Plastic contamination has gained significant attention in environmental studies, and microplastics (MP) and nanoplastics (NP) have become a research focus due to their durability and widespread presence in the environment (water, soil, and sediments). However, few studies have comprehensively and integratively assessed MP dynamics in soils, considering the NP/MP-soil-plant-insect interaction. Some studies have highlighted the effects of MP on soil porosity, structure, nutrient availability, enzymatic activity, and microbial diversity. The toxic effects of NP have been reported, demonstrating their potential to permeate plant membranes and interact with terrestrial biota. In insects, NP/MP toxicity is dose-dependent; however, some studies have indicated that low-dose exposure may induce resistance through adaptive stress (hormesis), which could negatively impact the control and management of species considered agricultural pests. Thus, this project proposes an interdisciplinary study on agricultural soils exposed to NP/MP and their effects on the soil-plant-insect system. The soils will be contaminated with NP/MP, varying in dosage, particle size, and functionalization. The study will evaluate NP/MP-soil interactions over two years, with annual crop cycles of maize. Soil enzymatic and physicochemical parameters will be analyzed, along with bioassays to expose the herbivorous species Spodoptera frugiperda to leaves grown in contaminated soils, aiming to assess the effects on the species' biological fitness. In addition, the aggregation of soil natural organic matter to NP/MP will be investigated. The findings of this study are expected to contribute to a systemic assessment of NP/MP impacts in agricultural contexts.