Microplastics in liquid biofertilizers: An overlooked threat to agricultural soil?

for sewage sludge-amended soils, indicating that MPs from biofertilizer represent only a minor fraction of total soil MPs contamination. Fragments dominated the MPs composition (98%), with most particles in the 5-50 μm size range. Polymer identification was achieved for 71% of particles, with paint-derived materials being most abundant (23%). Compared with other biosolids such as sewage sludge, biofertilizers represent a minor but measurable pathway for MPs inputs to agricultural soils. Nevertheless, the dominance of small-sized particles and long-term accumulation highlights the need to consider possible adverse effects of repeated biofertilizer application on soil ecosystems.