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 accumulatio...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:cbhI 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.展开更多
Saline–alkali land is an important cultivated land reserve resource for tackling global climate change and ensuring food security, partly because it can store large amounts of carbon(C). However, it is unclear how sa...Saline–alkali land is an important cultivated land reserve resource for tackling global climate change and ensuring food security, partly because it can store large amounts of carbon(C). However, it is unclear how saline–alkali land reclamation(converting saline–alkali land into cultivated land) affects soil C storage.We collected 189 adjacent pairs of salt-affected and cultivated soil samples(0–30 cm deep) from the Songnen Plain, eastern coastal area, Hetao Plain, and northwestern arid area in China. Various soil properties, the soil inorganic C(SIC), organic C(SOC), particulate organic C(POC), and mineral-associated organic C(MAOC) densities, and plant-and microbial-derived C accumulation were determined.Saline–alkali land reclamation inconsistently affected the SIC density but significantly(P < 0.001)increased the SOC density. The SOC, POC, and MAOC densities were predicted well by the integrative soil amelioration index. Saline–alkali land reclamation significantly increased plant-derived C accumulation and the plant-derived C to microbial-derived C ratios in all saline–alkali areas, and less microbial transformation of plant-derived C(i.e., less lignin degradation or oxidation) occurred in cultivated soils than salt-affected soils. The results indicated that saline–alkali land reclamation leads to plant-derived C becoming the dominant contributor of SOC storage. POC storage and MAOC storage were strongly linked to plant-and microbial-derived C accumulation, respectively, caused by saline–alkali land reclamation.Our findings suggest that saline–alkali land reclamation increases C storage in topsoil by preferentially promoting plant-derived C accumulation.展开更多
基金supported by the National Key R&D Program of China(Nos.2022YFD1500401 and 2022YFD1500203)the National Natural Science Foundation of China(Nos.42177332 and 41967002)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Nos.XDA24020104 and XDA28020203)the China Agriculture Research System(Nos.CARS-03-15 and CARS-52)。
文摘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:cbhI 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supported by the National Key Research and Development Program of China (2022YFD1500203 and2022YFD1500401)the Strategic Priority Research Program of Chinese Academy of Sciences (XDA24020104 and XDA28020203)+2 种基金the National Natural Science Foundation of China (42177332,42177292, and 42277336)the China Agriculture Research System(CARS-03-15 and CARS-52)the Youth Innovation Promotion Association of Chinese Academy of Sciences (2023325)。
文摘Saline–alkali land is an important cultivated land reserve resource for tackling global climate change and ensuring food security, partly because it can store large amounts of carbon(C). However, it is unclear how saline–alkali land reclamation(converting saline–alkali land into cultivated land) affects soil C storage.We collected 189 adjacent pairs of salt-affected and cultivated soil samples(0–30 cm deep) from the Songnen Plain, eastern coastal area, Hetao Plain, and northwestern arid area in China. Various soil properties, the soil inorganic C(SIC), organic C(SOC), particulate organic C(POC), and mineral-associated organic C(MAOC) densities, and plant-and microbial-derived C accumulation were determined.Saline–alkali land reclamation inconsistently affected the SIC density but significantly(P < 0.001)increased the SOC density. The SOC, POC, and MAOC densities were predicted well by the integrative soil amelioration index. Saline–alkali land reclamation significantly increased plant-derived C accumulation and the plant-derived C to microbial-derived C ratios in all saline–alkali areas, and less microbial transformation of plant-derived C(i.e., less lignin degradation or oxidation) occurred in cultivated soils than salt-affected soils. The results indicated that saline–alkali land reclamation leads to plant-derived C becoming the dominant contributor of SOC storage. POC storage and MAOC storage were strongly linked to plant-and microbial-derived C accumulation, respectively, caused by saline–alkali land reclamation.Our findings suggest that saline–alkali land reclamation increases C storage in topsoil by preferentially promoting plant-derived C accumulation.
