|Title||Role of fungal-bacterial co-inoculation and woody biochar on soil enzyme activity and heavy metal immobilization in serpentine soil|
|Publication Type||Journal Article|
|Year of Publication||2015|
|Authors||Bandara, Tharanga, Herath Indika, Kumarathilaka Prasanna, Seneviratne Mihiri, Seneviratne Gamini, Rajakaruna Nishanta, and Vithanage Meththika|
|Journal||Selected Works of Nishanta Rajakaruna|
Purpose In this study, we investigated the effect of biochar (BC) and fungal bacterial co-inoculation (FB) on soil enzymatic activity and immobilization of heavy metals in serpentine soil in Sri Lanka. Materials and methods A pot experiment was conducted with tomatoes (Lycopersicon esculentum L.) at 1, 2.5, and 5 % (w/w) BC ratios. Polyphenol oxidase, catalase and dehydrogenase activities were determined by idometric, potassium permanganate oxidisable, and spectrophotometric methods, respectively. Heavy metal concentrations were assessed by 0.01 M CaCl2 and sequential extraction methods. Results and discussion An increase in BC application reduced polyphenol oxidase, dehydrogenase, and catalase activity. The application of FB increased soil dehydrogenase activity, with the maximum activity found in 1 % BC700 + FB treatment. Moreover, the CaCl2 extractable metals (Ni, Mn, and Cr) in 5 % BC700 amended soil decreased by 92, 94, and 100 %, respectively, compared to the control. Sequential extraction showed that the exchangeable concentrations of Ni, Mn, and Cr decreased by 55, 70, and 80 % in 5 % BC700, respectively. Conclusions Results suggest that the addition of BC to serpentine soil immobilizes heavy metals and decreases soil enzymatic activities. The addition of FB to serpentine soil improves plant growth by mitigating heavy metal toxicity and enhancing soil enzymatic activities.