Long‐term successive biochar application increases plant lignin and microbial necromass accumulation but decreases their contributions to soil organic carbon in rice–wheat cropping system
Zhaoming Chen,
Lili He,
Jinchuan Ma,
Junwei Ma,
Jing Ye,
Qiaogang Yu,
Ping Zou,
Wanchun Sun,
Hui Lin,
Feng Wang,
Xu Zhao,
Qiang Wang
Affiliations
Zhaoming Chen
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences Hangzhou China
Lili He
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences Hangzhou China
Jinchuan Ma
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences Hangzhou China
Junwei Ma
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences Hangzhou China
Jing Ye
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences Hangzhou China
Qiaogang Yu
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences Hangzhou China
Ping Zou
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences Hangzhou China
Wanchun Sun
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences Hangzhou China
Hui Lin
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences Hangzhou China
Feng Wang
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences Hangzhou China
Xu Zhao
State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro‐Ecosystem Observation and Research Station Institute of Soil Science, Chinese Academy of Sciences Nanjing China
Qiang Wang
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐Products Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences Hangzhou China
Abstract Biochar application is widely recognized as an effective approach for increasing soil organic carbon (SOC) and mitigating climate change in agroecosystems. However, the effects of biochar application on net accumulations and relative contributions of different SOC sources remain unclear. Here, we explored the effects of biochar application on plant‐derived (PDC) and microbial necromass C (MNC) in a 10‐year experimental rice–wheat rotation field receiving four different intensities of biochar application (0, 2.25, 11.5, and 22.5 t ha−1 for each crop season), using phospholipid fatty acids (PLFAs), lignin phenols and amino sugars as biomarkers of microbial biomass, PDC and MNC, respectively. Our results showed that biochar application increased SOC content and stock by 32.6%–203% and 26.4%–145%, respectively. Higher biochar application (11.5 and 22.5 t ha−1) increased soil pH, total nitrogen (TN), total phosphorus (TP), SOC/TN, and root biomass. In addition, higher biochar application enhanced bacterial, fungal, and total microbial biomass. Plant lignin phenols and MNC contents significantly increased, whereas their contributions to SOC significantly decreased with the increase in biochar application rates due to the disproportionate increase in PDC and MNC, and SOC. Fungal necromass had a greater contribution to SOC than bacterial necromass. The fungal/bacterial necromass decreased from 2.56 to 2.26 with increasing biochar application rates, because of the higher abundances of bacteria than that of fungi as indicated by PLFAs under higher biochar application rates. Random forest analyses revealed that pH, TP, and SOC/TN were the main factors controlling plant lignin and MNC accumulation. Structural equation modeling revealed that biochar application increased lignin phenols by stimulating root biomass, whereas enhanced MNC accumulation was primarily from increased microbial biomass and lignin phenols. Overall, our findings suggest that biochar application increases the accumulation of the two SOC sources but decreases their contributions to SOC in paddy soils.
