The process of disintegration of biodegradable bioplastics is often studied using the residual materials, which can be collected by the naked eye and examined through changes in crystallinity, functional groups, thermal properties, and molecular weight. However, disintegration products, such as microplastics, nanoplastics, oligomers, monomers, and additives, are often overlooked because of the challenges in identifying and measuring them. This chapter provides an analysis of recent advancements in extraction (high-density saline solutions, modified Fenton at room temperature), identification (microscopy, IR, Raman, DSC), and quantification (DLS, NMR, TOC, MS) methodologies for (bio)microplastics, with a particular focus on those from agricultural settings. These techniques require a library of (bio)microplastics for calibration, thereby providing abundant research possibilities. Strategies currently under experimentation, such as magnetic separation, tracer molecules, biotechnological techniques, and EIS, are also included. The study of agricultural (bio)microplastics, known as agro-(bio)microplastics, is critical for understanding their impact on the environment.