Impact of Plastic Residues on Soil Properties and Crop Productivity: A Comprehensive Research Study

The sources that have led to the development of plastic residues, microplastics, and macroplastics are plastic mulching, sewage sludge, compost, irrigation with contaminated water, and atmospheric deposition. These residues modify the physical, chemical, and biological characteristics of soil, eventually influencing crop yield. Objectives: To determine the impact of plastic residues on soil health and crop productivity through the evaluation of soil properties, microbial activity, and plant growth reactions to different levels of contamination. Methods: Soil and plant samples were taken in agricultural fields classified using the intensity of contamination. Density separation was used to extract microplastic particles, and FTIR and SEM were used to characterize the particles. Physical (bulk density, porosity, water-holding capacity), chemical (pH, organic matter, nutrient availability), and biological (microbial biomass, enzymatic activities, earthworm bioassays) soil parameters were examined. The performance of crops was determined in terms of germination, biomass, nutrient uptake, and yield. ANOVA and regression were statistically applied to analyze data. Results: Plastic debris interfered with the soil structure, decreased nutrient cycling, microbial activity, and suppressed crop development, causing drastic losses in production. Although plastic mulching originally improved the moisture content of soil and the control of weeds, the accumulation of the persistent residues over time produced adverse effects on soil fertility. Conclusions: Plastic wastes are dangerous in the long run to the soil ecosystems and agricultural productivity. The plastic pollution of the soil by plastics and the threat to food security require some urgency in the form of sustainable alternatives, better recycling, and stringent waste management policies.