The influence of compost amendments on bioaccumulation of potentially toxic elements by pea plant cultivated in mine degraded soils

Abstract

Potential toxic metal (PTE) accumulation in soil and water is one of the major sources of food crop contamination. PTE remediation from soil can be enhanced by the addition of organic matter to the growing media. An experiment was carried out to investigate the effect of different organic amendments on the accumulation of PTEs in pea plant grown on mine degraded soils. Mining soils from chromite mine (CM), soap stone mine (SSM), manganese mine (MM), and quartz mine (QM) were mixed with vermicompost (VC), leaf mould (LC), and spent mushroom compost (SMC) along with garden soil at 1:1:1 ratio. Various growth and yield-related attributes of pea plant as well as PTE concentrations in soil and plants were studied. The highest Cd (2.62 mg kg−1) and Cr (13.6 mg kg−1) concentration was reported in CM soil, while Pb (23.3 mg kg−1) and Mn (59.2 mg kg−1) concentration in SSM and MM soil, respectively. Mining soils significantly reduced the plant growth and yield, while organic amendments reduced the PTE availability and increased pea plant growth. Comparing the various organic fertilizers used, it was observed that VC efficiently reduced Cd, Cr, Pb, and Mn uptake by pea plant, subsequently, improved pea plant growth and productivity. In order to assess the effects of various amendments on PTE health risk reduction, various risk indices including plant tranfser factor, average daily intake, health risk, target hazard quotient, and target cancer risk were also calculated and the results revealed that application of compost particularly VC significantly reduced the dietary intake and health risks of PTEs.