Potential Role of Combined Microbial Inoculants and Plant of Limnocharis flava on Eliminating Cadmium from Artificial Contaminated Soil

Abstract

This study aimed to investigate the possibility of eliminating cadmium (Cd) from contaminated agricultural soil using a combination of microbial inoculants of Penicillium chrysogenum fungus and Bacillus licheniformis with Limnocharis flava plants. Limnocharis flava (L. flava) and microbial inoculants with four Cd levels, including 2.05 (T1 control), 5 (T2), 10 (T3), and 20 mg/kg (T4), respectively, were tested in green house conditions. Cd accumulation was evaluated to assess the safety limit of the Cd concentration in the edible parts of L. flava. The results showed that the application of the microbial inoculants facilitated the stress tolerance of the plants caused by a Cd accumulation in the soil matrix. The use of Penicillium chrysogenum and Bacillus licheniform in combination with L. flava increased the Cd accumulation in plant biomass. The total Cd after the experiment varied between 4.86 and 18.44 mg/kg in dry, clean soil, equivalent to reduction rates of 2.80, 4.40, and 7.80%, respectively. Meanwhile, the availability of Cd in soil was significantly reduced by 12.50, 13.04, 13.33, and 13.93%, respectively. Consequently, the microbial inoculants helped the plants to grow healthily, increased the yield, and reduced the total and available Cd content of contaminated agricultural land up to a concentration level of 5 mg/kg.