The combined effects of plastic pollution and agricultural runoff are causing aquatic ecosystems to become more stressed, endangering the resilience of the ecosystem and the stability of the food web. Plastic matter for plant cultivation and protection help farmers produce more crops, improve the quality of their agricultural products, and use less water around the world to lessen the impact they have on the environment. Through surface runoff, soil leaching, and poor waste management, micro and nano plastics find their way into aquatic environments. Agricultural runoff also contributes heavy metals, pesticides, herbicides, and excess nutrients. MNPs alter the toxicological effects, durability, and accessibility of chemical contaminants when they are released through interactions. As transporters, they help transmit agricultural chemicals and contaminants between different trophic levels, which leads to metabolic disruption, oxidative damage, bioaccumulation, and reduced reproduction in aquatic organisms. Such interactions disturb food web dynamics, reduce ecological resilience, and hinder the transfer of energy. By incorporating contemporary studies on the interconnected pathways linking aquatic contaminants, plastic pollution, and runoff from agriculture, this chapter underlines their combined and long-term ecological impacts. Additionally, it highlights the need for sustainable mitigation strategies, including the development of chemical and microbiological degradation technologies, improved crop residue management, and biodegradable replacements to conventional plastics. In the face of increasing agricultural intensification and plastic dependence, it is critical to fortify such multidisciplinary strategies towards a more environmentally friendly utilisation of plastics in agriculture in order to mitigate the ecological risks of MNPs, restore aquatic ecosystem function, and protect biodiversity and human health.