Biofilmed Biofertilizers for Rhizo-Remediation and Consumer Health-Friendly Potato Production

Excessive use of chemical fertilizers (CF) in agriculture with soil degradation is associated with risks such as accumulating toxic chemical contaminants in the soil and also edible parts. Two pot experiments were conducted under greenhouse conditions to evaluate rhizo-remediation abilities of different biofilm biofertilizer (BFBF) and CF treatments on nitrosamine and heavy metal contaminants. Potting media were added with dimethyl nitrosamine and selected heavy metal solution mixtures of CdCl2 and PbCl2 separately as the test contaminants. Potato plants as the test crop grown in the pots with the contaminants were treated with different combinations of BFBF (a combination of Bacillus pumilus, Bradyrhizobium japonicum, Bacillus subtilis and Trichoderma harzianum) and CF. Rhizo-remediation abilities of the treatments were evaluated by measuring the nitrosamine and heavy metal content in the soil and potato tuber. Results showed that the BFBF applied with 50 % of recommended CF rate for potato (50CB) significantly (P less than 0.05) reduced nitrosamine in tubers and in the potting media.50CB showed significantly (P less than 0.05) the lowest tuber and soil Cd and Pb contents in comparison with 100 % CF (100C). The findings also confirmed that the soil health can be enhanced by the BFBF through the reduction of soil chemical contaminants.