Open Access

ARTICLE

Biochar-Induced Priming Effects in Young and Old Poplar Plantation Soils

by Weiwei Lu, Yirui Zhang, Yixian Yao, Yuying Wu, Han Y. H. Chen, Hailin Zhang, Jia Yu, Caiqin Shen, Qi Liu, Honghua Ruan

1 College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
2 Faculty of Natural Resources Management, Lakehead University, Thunder Bay, ON, P7B 5E1, Canada
3 Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
4 Advanced Analysis and Testing Center, Nanjing Forestry University, Nanjing, 210037, China
5 State Owned Forest Farm of Dongtai, Dongtai, 224200, China
6 College of Forestry, Nanjing Forestry University, Nanjing, 210037, China

* Corresponding Authors: Weiwei Lu. Email: ; Honghua Ruan. Email:

Phyton-International Journal of Experimental Botany 2020, 89(1), 13-26. https://doi.org/10.32604/phyton.2020.09125

Received 13 November 2019; Accepted 27 November 2019; Issue published 01 March 2020

Abstract

The priming effect (PE) induced by biochar provides a basis for evaluating its carbon (C) sequestration potential in soils. A 60 days’ laboratory incubation was conducted, which involved the amendment of biochar (1% of soil mass) produced from rice straw at 300ºC (B300) and 500ºC (B500) to young (Y) and old (O) poplar plantation soils, with the aim of studying the responses of biochar-induced PEs to poplar plantation ages. This incubation included six treatments: Y + CK (control), Y + B300, Y + B500, O + CK, O + B300, and O + B500. Carbon dioxide (CO₂) emissions were significantly increased (p < 0.05) in the B300 amended soils, while it was decreased in the B500 amended soils compared to the CK. The primed CO₂ emissions were 2.35 times higher in the Y + B300 than the O + B300 treatments, which was measured to be 18.6 and 5.56 mg C·kg^-1 with relative PEs of 12.4% and 3.35%, respectively. However, there was little difference between the primed CO2 emissions in Y + B500 and O + B500 treatments, which were measured to be -24.9 and -29.6 mg·C·kg^-1 with relative PEs of -16.6% and -17.8%, respectively. Dissolved organic carbon (DOC) was significantly lower in the young poplar plantation soil than that in the old poplar plantation soil regardless of biochar amendment throughout the incubation, indicating greater C-limit of soil microorganisms in the young poplar plantation soil. Using ¹³C isotope tracing, neither B300 nor B500 decreased native soil-derived DOC, which indicated that the negative B500-induced PEs were not due to a reduction in the availability of native soil-derived C. In conclusion, the response of biochar-induced PEs to poplar plantation age depends on biochar types while soil available C indirectly affects biocharinduced PEs. Further studies should focus on how the interactive effects between soil C availability and microbial community impacts biochar-induced PEs.

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