Abstract
Macroaggregate organic carbon(Macro-OC)accumulation in paddy soils is of great significance in promoting multiple agroecosystem services.However,the effects of different fertilization practices on Macro-OC accumulation in paddy soils at the regional scale have not been comprehensively investigated.Here,we conducted long-term fertilization field experiments at four sites,Taoyuan,Wangcheng,Jinxian,and Suzhou,in the subtropical area of China to reveal the effects of inorganic and organic-inorganic(OIF)fertilization on Macro-OC accumulation and its relationships with important microbial traits(the abundance ratio of GH48:cbhl genes and the richness of keystone bacterial taxa)in paddy soils.The results showed that long-term fertilization(particularly OIF)significantly increased the content of Macro-OC,which mainly consisted of particulate organic carbon(C).Organic-inorganic fertilization decreased the percentage of O-alkyl C but increased the percentages of alkyl,aromatic,and phenolic C.Organic-inorganic fertilization promoted the abundance of the bacterial cellulose-degrading gene GH48 retrieved from macroaggregates.The orders Anaerolineales,Bacillales,and Clostridiales were identified as keystone bacterial taxa in macroaggregates and were significantly correlated with the physical fraction and chemical structure of Macro-OC.Structural equation modeling revealed that fertilization-induced changes in soil pH and C:N ratio affected the richness of Anaerolineales,Bacillales,and Clostridiales,which was strongly associated with the increase of percentages of aromatic and phenolic C and further facilitated Macro-OC accumulation.Together,these results suggested that OIF promoted Macro-OC accumulation associated with key bacterial populations in paddy soils.The results provide an important basis for boosting soil C accrual in the subtropical rice-growing areas.
基金项目
National Key R&D Program of China(2022YFD1500401)
National Key R&D Program of China(2022YF-D1500203)
National Natural Science Foundation of China(42177332)
National Natural Science Foundation of China(41967002)
Strategic Priority Research Program of Chinese Academy of Sciences(XDA24020104)
Strategic Priority Research Program of Chinese Academy of Sciences(XDA28020203)
China Agriculture Research System(CARS-03-15)
China Agriculture Research System(CARS-52)
NETL
NSTL
万方数据