The presence of microplastics and nanoplastics (MNPs) in soils is becoming pervasive in most agroecosystems. The recent estimates suggest that the soil burden of MNPs in the agroecosystems is more than 0.5 megatons (Mt) annually. In all the agroecosystems, the transformation, migration, and transferring of MNPs, along with other contaminants, and the trophic transfer of MNPs can threaten the food web. MPs can exhibit negative and positive effects, or none, on the physical/chemical properties of soil, soil microbiota, invertebrates, and plant systems, depending on the polymer compositions, additives, and exposure time. Difficulties in comparing the studies on the effects of MNPs, as well as the discrepancies among them, are mostly due to variations in the methods followed for sampling, detection, quantification, and the categorization of particles, abundance, and exposure time. Since agricultural soils are important environmental reservoirs for diverse chemicals and contaminants, they provide milieus for several types of interactions of MNPs with soil biota. The present review critically examines the sources and transformation of MNPs in agricultural soils, the release and fate of additives, as well as their role as vectors of other potential contaminants and influence on soil physical/chemical properties, toxicities to soil biota (i.e., microorganisms, invertebrates, and plants), current regulatory guidelines for the mitigation of MNPs, and future research directions.

The circular bioeconomy framework addresses the global transition toward resource-efficient and low-carbon economies. The use of microalgae in sustainable circular bioeconomy largely suffers from energy consumption and underutilization of residual biomass, leading to greenhouse gas (GHG) emissions. This analysis-based perspective reveals that closed loop microalgal wastewater systems reduce GHG emissions by >50% and enhance valorization of residual biomass for value-added products compared to open loop approach. Integrating solar technologies in closed loop system further reduces GHG emissions by 99% and aligns with 11 UN sustainable development goals, making it a suitable model for a zero-waste and low-carbon circular bioeconomy.