Contrasting effects of banana peels waste and its biochar on greenhouse gas emissions and soil biochemical properties

The huge quantity of banana peels waste from juice industries and fruit markets every day is indicating a potential bio-resource which is major task for environment safety. It can be converted into useful material instead of being dumped in landfill site, and reduce the environment and economic problems. In this study, we compared the influence of banana peels waste and its biochar on greenhouse gas emissions, soil enzyme activities and chemical properties of soil at 90 days incubation period. There were five treatments of amendments: no amendment (Control), banana peel 1% (P1), banana peel 2% (P2), biochar 1% (B1) and biochar 2% (B2). Results indicated that biochar amendment significantly decreased cumulative nitrous oxide (N2O) emissions (37.1%-54.8%), whereas banana peels amendment did not significantly decrease cumulative N2O emissions (1.3%-5.3%) as compared to control. Biochar application decreased the soil ammonium nitrogen (NH4+-N) and nitrate nitrogen (NO3--N) with an increasing rate. Cumulative carbon dioxide (CO2) emissions for B1 and B2 treatments decreased 20.0% and 24.0% in comparison to the banana peel amendment, respectively. Cumulative methane (CH4) emissions were higher in peel waste than biochar amendment. Soil enzyme activities (urease, invertase and alkaline phosphatase) were significantly increased by biochar amendment. In contrast, banana peel amendment increased soil ammonium nitrogen, soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN), beta-glucosidase and urease activities. We concluded that banana peels waste conversion to biochar should be an alternate method of disposal since its application resulted in the reduced greenhouse gas emissions and improved the soil biochemical properties. This biochar should be further tested under field conditions to confirm the potential for mitigating of GHG emissions and soil biochemical properties. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.