摘要
Applying biochar amendment and manure in tea plantation ecosystems can diminish soil acidification and degradation.However,the impact of these practices on soil respiration and associated mechanisms remains unclear.In this study,we combined a two-year field experiment and laboratory analyses based on soil properties,functional genes,and microbial co-occurrence networks to explore the determinants of soil respiration intensity in a subtropical tea plantation with biochar amendment and manure application.The results showed that the effect of biochar amendment on soil respiration was unconspicuous.Although biochar amendment increased bacterial richness and Shannon index,biochar amendment did not alter the abundance of species associated with C-cycling functional genes.Besides directly adding recalcitrant C to the soil,biochar also indirectly enhanced C sequestration by weakly increasing soil carbon dioxide(CO_(2))emissions.However,replacing mineral fertilizer with manure significantly stimulated soil respiration in the tea plantation,resulting in a 36%increase in CO_(2) emissions over two years.The increase in CO_(2) emissions under the manure treatment was mainly attributed to the increased soil labile C pool,the activity of hydrolytic enzymes(e.g.,cellobiohydrolase and acetylglucosaminidase),and the relative abundance of functional genes associated with the C-cycle.This may also be related to the application of manure that increased the abundance of Gemmatimonadetes and altered ecological clusters in bacterial co-occurrence networks.Our correlation network analysis suggested that Gemmatimonadetes might be the potential hosts for C-cycling genes due to their strong positive correlation with the abundance of C-cycling genes.Overall,these findings provide new insights into soil respiration under biochar amendment and manure application in tea plantations and broaden the options for carbon sequestration in soils.
出处
《Biochar》
SCIE
CAS
CSCD
2023年第1期1259-1272,共14页
生物炭（英文）
基金
Jiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB324)
China Postdoctoral Science Foundation(2023M731725)
National Natural Science Foundation of China(42177285,42007072)
Jiangsu Provincial Special Project for Carbon Peak Carbon Neutrality Science and Technology Innovation(BE2022423,BE2022308)
Startup Foundation for Introducing Talent of Nanjing Agricultural University(030/804028).
