Biochar reduces the bioavailability and phytotoxicity of heavy metals
- 6.9k Downloads
Background and aims
Biochar has attracted research interest due to its ability to increase the soil carbon pool and improve crop productivity. The objective of this study was to evaluate the metal immobilizing impact of chicken manure- and green waste-derived biochars, and their effectiveness in promoting plant growth.
The immobilization and phytoavailability of Cd, Cu and Pb was examined using naturally contaminated shooting range and spiked soils. Biochar samples prepared from chicken manure and green waste were used as soil amendments.
Application of biochar significantly reduced NH4NO3 extractable Cd, Cu and Pb concentrations of soils, indicating the immobilization of these metals. Chicken manure-derived biochar increased plant dry biomass by 353 and 572% for shoot and root, respectively with 1% of biochar addition. This might be attributed to reduced toxicity of metals and increased availability of nutrients such as P and K. Both biochars significantly reduced Cd, Cu and Pb accumulation by Indian mustard (Brassica juncea), and the reduction increased with increasing amount of biochar application except Cu concentration. Metal sequential fractionation data indicated that biochar treatments substantially modified the partitioning of Cd, Cu and Pb from the easily exchangeable phase to less bioavailable organic bound fraction.
The results clearly showed that biochar application was effective in metal immobilization, thereby reducing the bioavailability and phytotoxicity of heavy metals.
KeywordsChicken manure-derived biochar Green waste-derived biochar Heavy metal Immobilization Bioavailability
This study was supported by the Ministry of Education, Science and Technology (MEST) and the Ministry of Knowledge Economy (MKE), Korea through Gyeongnam National University of Science and Technology as a Hub University for Industrial Collaboration (HUNIC). The authors thank Byoung Hwan Seo, Si Young Choi and Seul Ji Lee for laboratory assistance.
- Bloem J, Hopkins DW, Benedetti A (2006) Microbiological methods for assessing soil quality. Wallingford, UK: CABI Publishing 307Google Scholar
- Bolan NS, Naidu R, Syers JK, Tillman RW (1999) Surface charge and solute interactions in soils. Adv Agron 67:88–141Google Scholar
- Bowden JW, Posner AM, Quirk JP (1977) Ionic adsorption on variable charge mineral surfaes. Theoretical charge development and titration curves. Aust J Soil Res 15:121–136Google Scholar
- Lehmann J, Gaunt J, Rondon M (2006) Bio-char sequestration in terrestrial ecosystems—a review. Mitig Adapt Strategy Global Change 11:403–427Google Scholar
- NEPC, National Environment Protection Council (1999) National Environment Protection (Assessment of Site Contamination) Measure: Schedule B(1) Guideline on the Investigation Levels for Soil and Groundwater, AustraliaGoogle Scholar
- Sohi S, Lopez-Capel E, Krull E, Bol R (2009) Biochar’s role in soil and climate change: a review of research needs, CSIRO Land and Water Science Report 05/09:1–57, AustraliaGoogle Scholar
- Thies JE, Rillig MC (2009) Characteristics of biochar: biological properties. In: Lehmann J, Joseph S (eds) Biochar for environmental management. Earthscan, USAGoogle Scholar