Assessing LDPE microplastics' impact on green gram (Vigna radiata L. Wilczek) cultivation: A greenhouse pot experiment

Abstract

Plastic pollution, particularly from microplastics (MPs), poses a significant threat to agricultural ecosystems. This study investigates the impact of Low-Density Polyethylene (LDPE) microplastics on green gram (Vigna radiata) cultivation, focusing on growth, yield, and soil nutrient dynamics. A completely randomized design with nine treatments of varying LDPE concentrations was used in a controlled poly house environment. Soil analysis assessed mechanical and physico-chemical properties using established methods. Green gram variety Co (Gg) 8 was cultivated during the Rabi season, with comprehensive crop management including germination tests, pot culture preparations, precise fertilizer application, and essential cultural operations. Results indicated significant correlations between LDPE concentrations and green gram growth parameters, with higher concentrations having detrimental effects (correlation coefficient = −0.75, p < 0.05). LDPE treatments also influenced plant nutrient uptake, showing inverse correlations with nitrogen (N), phosphorus (P), and potassium (K) uptake (correlation coefficient = −0.82, p < 0.01). Post-harvest soil analysis revealed significant variations in available nutrients, with LDPE-treated soils exhibiting higher N, P, and K levels compared to control groups (correlation coefficient = 0.78, p < 0.01). Infrared spectroscopy confirmed the presence of LDPE microplastics in soil and plant samples, identified by characteristic (CO) and (C–H) stretching vibrations. These findings highlight the complex interactions between LDPE microplastics and agricultural systems, emphasizing the need for sustainable practices to mitigate the adverse effects of plastic pollution on agriculture. Statistical analysis using the CRD framework and correlation and regression analyses ensured robust interpretation of the data.