Fate, Transport Pathways, and Accumulation of Microplastics Agricultural Soil and Their Interaction with Agrochemicals

Microplastics (MPs), defined as plastic particles smaller than 5 mm in size, have emerged as a significant environmental concern worldwide due to their ubiquity and potential adverse effects on ecosystems. While the majority of research has focused on microplastic pollution in aquatic environments, there is a growing recognition of their presence and potential impact in agricultural soils. This chapter aims to provide an overview of the fate, transport pathways, and accumulation of MPs in agricultural soil, as well as their interaction with agrochemicals. The fate of MPs in agricultural soil is influenced by various factors, including their size, shape, density, and surface properties. Once introduced into the soil, MPs can undergo physical, chemical, and biological transformations, such as fragmentation, adsorption of organic and inorganic substances, and microbial degradation. These processes can affect their distribution, mobility, and persistence in the soil environment. The transport pathways of MPs in agricultural soil are diverse and can involve both natural and anthropogenic mechanisms. Natural pathways include erosion, wind dispersion, and the movement of soil fauna, while anthropogenic pathways include agricultural practices, such as the application of plastic mulch or irrigation with microplastic-contaminated water. Understanding these transport pathways is crucial for assessing the potential for microplastic migration to other environmental compartments, such as water bodies or plants. Accumulation of MPs in agricultural soil can have implications for soil health, nutrient cycling, and crop productivity. Microplastics can adsorb agrochemicals, such as pesticides and fertilizers, potentially altering their behavior, bioavailability, and toxicity. Conversely, the presence of agrochemicals can influence the fate and behavior of MPs in soil, including their degradation or persistence. This chapter also highlights the need for standardized methodologies to quantify and characterize MPs in agricultural soil, as well as the challenges associated with their detection and analysis. Furthermore, potential mitigation strategies, such as sustainable agricultural practices and the development of biodegradable alternatives to conventional plastics, are discussed to minimize the introduction and accumulation of MPs in agricultural soil. Overall, this chapter provides a comprehensive understanding of the fate, transport pathways, and accumulation of MPs in agricultural soil, emphasizing their interaction with agrochemicals. It underscores the importance of addressing this emerging issue to safeguard soil quality, agricultural sustainability, and environmental health.