TY - JOUR

T1 - Inorganic carbon is overlooked in global soil carbon research: A bibliometric analysis

AU - Raza, Sajjad

AU - Irshad, Annie

AU - Margenot, Andrew

AU - Zamanian, Kazem

AU - Li, Nan

AU - Ullah, Sami

AU - Mehmood, Khalid

AU - Khan, Muhammad Ajmal

AU - Siddique, Nadeem

AU - Zhou, Jianbin

AU - Mooney, Sacha J.

AU - Kurganova, Irina

AU - Zhao, Xiaoning

AU - Kuzyakov, Yakov

N1 - Funding Information: Global SOC research was funded by more than 20,000 agencies, and a major share in publications (31 %) and citations (38 %) was contributed by the top 10 funding agencies ( Table 2 ). Seven out of the top 10 funders were from China and the USA. The National Natural Science Foundation of China produced 11 % of global SOC research, whereas the National Science Foundation of the USA contributed 5 % of SOC research but had greatest research impact (80 citations publication -1 ). We found similar trends for SOC-climate change research ( Table S2 ). SIC research was supported by approximately 1000 reported funders, about 20-fold less than for SOC. About 40 % of SIC research and 50 % of citations were contributed by the top 10 funding agencies ( Table 2 ). Funding agencies from China and the USA dominated in supporting SIC research. The National Science Foundation of the USA funded the greatest number of publications and citations, whereas the studies funded by the UK’s National Environment Research Council had the greatest research impact. SIC research focused on climate change was also dominantly funded by China and the USA ( Table S2 ). Funding Information: S.R. was supported by National Natural Science Foundation of China (42150410386). S.R. and S.J.M. were funded by Biotechnology and Biological Sciences Research Council (BBSRC) project Delivering Sustainable Wheat (DSW) (BB/X011003/1). X.Z. was supported by Xinjiang Tian Chi Specially-Appointed Professor Project; Jiangsu Provincial Science and Technology Innovation Special Fund Project of Carbon Emission Peak and Carbon Neutralization (frontier and basis) (BK20220016) and Jiangsu Specially-Appointed Professor Project (R2020T29). Y.K was supported by the RUDN University Strategic Academic Leadership Program. I.K. was supported by the West-Siberian Interregional Science and Education Centers Project No. 89-DON (1), and the Project CarboRus (075-15-2021-610).

PY - 2024/3

Y1 - 2024/3

N2 - Soils are a major player in the global carbon (C) cycle and climate change by functioning as a sink or a source of atmospheric carbon dioxide (CO 2). The largest terrestrial C reservoir in soils comprises two main pools: organic (SOC) and inorganic C (SIC), each having distinct fates and functions but with a large disparity in global research attention. This study quantified global soil C research trends and the proportional focus on SOC and SIC pools based on a bibliometric analysis and raise the importance of SIC pools fully underrepresented in research, applications, and modeling. Studies on soil C pools started in 1905 and has produced over 47,000 publications (>1.7 million citations). Although the global C stocks down to 2 m depth are nearly the same for SOC and SIC, the research has dominantly examined SOC (>96 % of publications and citations) with a minimal share on SIC (<4%). Approximately 40 % of the soil C research was related to climate change. Despite poor coverage and publications, the climate change-related research impact (citations per document) of SIC studies was higher than that of SOC. Mineral associated organic carbon, machine learning, soil health, and biochar were the recent top trend topics for SOC research (2020–2023), whereas digital soil mapping, soil properties, soil acidification, and calcite were recent top trend topics for SIC. SOC research was contributed by 151 countries compared to 88 for SIC. As assessed by publications, soil C research was mainly concentrated in a few countries, with only 9 countries accounting for 70 % of the research. China and the USA were the major producers (45 %), collaborators (37 %), and funders of soil C research. SIC is a long-lived soil C pool with a turnover rate (leaching and recrystallization) of more than 1000 years in natural ecosystems, but intensive agricultural practices have accelerated SIC losses, making SIC an important player in global C cycle and climate change. The lack of attention and investment towards SIC research could jeopardize the ongoing efforts to mitigate climate change impacts to meet the 1.5–2.0 °C targets under the Paris Climate Agreement of 2015. This bibliographic study calls to expand the research focus on SIC and including SIC fluxes in C budgets and models, without which the representation of the global C cycle is incomplete.

AB - Soils are a major player in the global carbon (C) cycle and climate change by functioning as a sink or a source of atmospheric carbon dioxide (CO 2). The largest terrestrial C reservoir in soils comprises two main pools: organic (SOC) and inorganic C (SIC), each having distinct fates and functions but with a large disparity in global research attention. This study quantified global soil C research trends and the proportional focus on SOC and SIC pools based on a bibliometric analysis and raise the importance of SIC pools fully underrepresented in research, applications, and modeling. Studies on soil C pools started in 1905 and has produced over 47,000 publications (>1.7 million citations). Although the global C stocks down to 2 m depth are nearly the same for SOC and SIC, the research has dominantly examined SOC (>96 % of publications and citations) with a minimal share on SIC (<4%). Approximately 40 % of the soil C research was related to climate change. Despite poor coverage and publications, the climate change-related research impact (citations per document) of SIC studies was higher than that of SOC. Mineral associated organic carbon, machine learning, soil health, and biochar were the recent top trend topics for SOC research (2020–2023), whereas digital soil mapping, soil properties, soil acidification, and calcite were recent top trend topics for SIC. SOC research was contributed by 151 countries compared to 88 for SIC. As assessed by publications, soil C research was mainly concentrated in a few countries, with only 9 countries accounting for 70 % of the research. China and the USA were the major producers (45 %), collaborators (37 %), and funders of soil C research. SIC is a long-lived soil C pool with a turnover rate (leaching and recrystallization) of more than 1000 years in natural ecosystems, but intensive agricultural practices have accelerated SIC losses, making SIC an important player in global C cycle and climate change. The lack of attention and investment towards SIC research could jeopardize the ongoing efforts to mitigate climate change impacts to meet the 1.5–2.0 °C targets under the Paris Climate Agreement of 2015. This bibliographic study calls to expand the research focus on SIC and including SIC fluxes in C budgets and models, without which the representation of the global C cycle is incomplete.

KW - Bibliometric analysis

KW - Carbon sequestration

KW - Carbon stocks

KW - Climate change

KW - CO emission

KW - Soil inorganic carbon

KW - Soil organic carbon

UR - http://www.scopus.com/inward/record.url?scp=85186517471&partnerID=8YFLogxK

U2 - 10.1016/j.geoderma.2024.116831

DO - 10.1016/j.geoderma.2024.116831

M3 - Article

VL - 443

JO - GEODERMA

JF - GEODERMA

SN - 0016-7061

M1 - 116831

ER -