In Vivo Genotoxicity of Rice Husk Biochar on Eudrilus eugeniae in Soil

Biochar (char-product), generated by pyrolyzing organic materials, is produced for the intended use of land application to promote carbon sequestration, soil improvement and crop-yield. Despite the benefits biochar applications offers, scientific probing on impacts that may result from amendments with biochar is still fragmented. In this study, impact of biochar on Eudrilus eugeniae DNA was investigated. Rice-husk biochar was applied to soil at rates up to 80% d/w and earthworms were exposed for 35-day. Impact on DNA was measured using electrophoresis-gel-extraction-method. Data obtained showed that biochar application over 25% resulted in decreased survival. Electrophoresis-gel-analysis showed that DNA decreased from 450 to 300 bp in biochar soils (p = 0.002). Biochar rates (5%-25%) induced DNA damage. The DNA showed smeared bands or tail; indicating DNA degradation and/or damage. DNA damage is a clear evidence of negative impact of biochar(s) to soil-biota; suggesting that loading of soil with biochar could have serious consequences on soil-fauna.