Microplastic (MP) pollution is a growing concern, yet its impacts on agroecosystems remain poorly understood. This study investigates MP contamination in the agroecosystems of Sialkot, Pakistan, and its potential effects on the growth, physio-biochemical attributes, and yield of potato (Solanum tuberosum L.). Plant and soil samples from 10 diverse agricultural fields were collected and analyzed for MP contamination. FTIR analysis revealed widespread MP presence in the soil across all sites. Fragment, film, and fiber types dominated, with low-density polyethylene (22.42 %), high-density polyethylene (18.05 %), and polystyrene (12.3 %) being the most prevalent polymers. A significant variation in plant growth parameters was observed. The number of tubers per plant also exhibited a significant difference, as evidenced by the decline in potato yield with increasing levels of MP contamination. Potato yield showed a negative correlation with MP contamination levels. The nutrients (Zn, Cu, Ni, and Na) uptake in plant shoots was also observed to be decreased except for Mg and Mn at all sites. This study showed that MPs are contaminating our agricultural lands and they may affect growth and yield of potato. Additional research is needed to understand the underlying mechanisms and develop mitigation strategies to improve agricultural productivity and food security.
A novel kinetic model has been developed to explain the degradation of total petroleum hydrocarbons. Microbiome engineered biochar amendment may result in a synergistic impact on degradation of total petroleum hydrocarbons (TPHs). Therefore, the present study analyzed the potential of hydrocarbon-degrading bacteria A designated as Aeromonas hydrophila YL17 and B as Shewanella putrefaciens Pdp11 morphological characterized as rod shaped, anaerobic and gram-negative immobilized on biochar, and the degradation efficiency was measured by gravimetric analysis and gas chromatography-mass spectrometry (GC-MS). Whole genome sequencing of both strains revealed the existence of genes responsible for hydrocarbon degradation. In 60 days remediation setup, the treatment consisting of immobilization of both strains on biochar proved more efficient with less half-life and better biodegradation potentials compared to biochar without strains for decreasing the content of TPHs and n-alkanes (C12-C18). Enzymatic content and microbiological respiration showed that biochar acted as a soil fertilizer and carbon reservoir and enhanced microbial activities. The removal efficiency of hydrocarbons was found to be a maximum of 67% in soil samples treated with biochar immobilized with both strains (A + B), followed by biochar immobilized with strain B 34%, biochar immobilized with strain A 29% and with biochar 24%, respectively. A 39%, 36%, and 41% increase was observed in fluorescein diacetate (FDA) hydrolysis, polyphenol oxidase and dehydrogenase activities in immobilized biochar with both strains as compared to control and individual treatment of biochar and strains. An increase of 35% was observed in the respiration rate with the immobilization of both strains on biochar. While a maximum colony forming unit (CFU/g) was found 9.25 with immobilization of both strains on biochar at 40 days of remediation. The degradation efficiency was due to synergistic effect of both biochar and bacteria based amendment on the soil enzymatic activity and microbial respiration.