Long-term Effects of Biochar Application on Physicochemical Properties and Microplastic Accumulation in Aeolian Sandy Soils
This study investigated the long-term effects of biochar application on physicochemical properties and microplastic accumulation in aeolian sandy soils, based on a field experiment established in 2014. After seven years of mulched cultivation, soil samples were collected from 0–30 cm and 30–60 cm depths. Biochar application significantly increased soil porosity and available nitrogen, phosphorus, and potassium contents, while reducing bulk density. At a biochar rate of 126.00 t·hm−2, soil water content was significantly reduced. Microplastic abundance averaged 3459.57 pieces·kg−1 in the 0–30 cm layer, with the highest abundance at 126.00 t·hm−2; in the 30–60 cm layer, average abundance was 3163.50 pieces·kg−1, with the highest at 63.00 t·hm−2. Microplastics were predominantly transparent, film-shaped, and 0–0.5 mm in size. The results indicate that biochar application significantly increased microplastic abundance in aeolian sandy soils, providing insights into microplastic adsorption and enrichment in agricultural ecosystems. Further research is needed to elucidate underlying mechanisms.