Shifts in microbial community and water-extractable organic matter composition with biochar amendment in a temperate forest soil |
| |
| Affiliation: | 1. Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China;2. Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing 210095, China;3. Zhejiang Provincial Key Laboratory of Carbon Cycling in Forest Ecosystems and Carbon Sequestration, School of Environmental and Resource Sciences, Zhejiang A & F University, Lin''an, Hangzhou 311300, China;1. Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, People''s Republic of China;2. Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, Ningbo 315800, People''s Republic of China;3. University of Chinese Academy of Sciences, Beijing 100049, People''s Republic of China;4. The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK;5. Department of Environmental Science, University of Peshawar, Pakistan |
| |
| Abstract: | Biochar amendment in soil has been proposed as a carbon sequestration strategy which may also enhance soil physical and chemical properties such as nutrient and water holding capacity as well as soil fertility and plant productivity. However, biochar may also stimulate microbial activity which may lead to increased soil CO2 respiration and accelerated soil organic matter (OM) degradation which could partially negate these intended benefits. To investigate short-term soil microbial responses to biochar addition, we conducted a 24 week laboratory incubation study. Biochar produced from the pyrolysis of sugar maple wood at 500 °C was amended at concentrations of 5, 10 and 20 t/ha in a phosphorus-limited forest soil which is under investigation as a site for biochar amendment. The cumulative soil CO2 respired was higher for biochar-amended samples relative to controls. At 10 and 20 t/ha biochar application rates, the concentration of phospholipid fatty acids (PLFAs) specific to Gram-positive and Gram-negative bacteria as well as actinomycetes were lower than controls for the first 16 weeks, then increased between weeks 16–24, suggesting a gradual microbial adaptation to altered soil conditions. Increases in the ratio of bacteria/fungi and lower ratios of Gram-negative/Gram-positive bacteria suggest a microbial community shift in favour of Gram-positive bacteria. In addition, decreasing ratios of cy17:0/16:1ω7 PLFAs, a proxy used to examine bacterial substrate limitation, suggest that bacteria adapted to the new conditions in biochar-amended soil over time. Concentrations of water-extractable organic matter (WEOM) increased in all samples after 24 weeks and were higher than controls for two of the biochar application rates. Solution-state 1H NMR analysis of WEOM revealed an increase in microbial-derived short-chain carboxylic acids, lower concentrations of labile carbohydrate and peptide components of soil OM and potential accumulation of more recalcitrant polymethylene carbon during the incubation. Our results collectively suggest that biochar amendment increases the activity of specific microorganisms in soil, leading to increased CO2 fluxes and degradation of labile soil OM constituents. |
| |
| Keywords: | Soil organic matter Phospholipid fatty acids Soil respiration Carbon dioxide Nuclear magnetic resonance |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
