Soil Science Society of America Journal · 2021
Root‐zone soil organic carbon enrichment is sensitive to land management across soil types and regions
Franzluebbers, A. J.
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Root‐zone soil organic carbon enrichment is sensitive to lan…
Abstract
Measuring and monitoring changes in soil organic C (SOC) concentrations and stocks are important for understanding ecosystem functions. Sequestration of SOC has traditionally been measured from resource‐intensive studies over extended periods of time, but an alternative approach of calculating root‐zone SOC enrichment is described here as a proxy for estimating SOC sequestration using nonlinear distribution of SOC concentration in the surface 30 cm. From literature data across 52 studies, estimated SOC concentration at 30‐cm depth was not different between pairs of conservation management and conventional‐till cropland, suggesting support for the concept of using SOC concentration at 30‐cm depth as a baseline concentration from which enrichment can be calculated. Root‐zone SOC enrichment across this ( n = 420) and an earlier study ( n = 171) was 12.0 ± 0.6 Mg C ha –1 (mean ± SE) under conventional‐till cropland ( n = 209), 16.1 ± 0.6 Mg C ha –1 under no‐till cropland ( n = 269), 20.6 ± 1.0 Mg C ha –1 under grassland ( n = 90), and 25.8 ± 3.8 Mg C ha –1 under woodland ( n = 23). Regional climatic conditions and soil texture were important in influencing baseline SOC storage and total SOC stock but were minor factors in affecting root‐zone SOC enrichment with conservation management. Root‐zone SOC enrichment is a relatively simple and straightforward calculation method to indicate SOC sequestration, and if deployed across a diversity of management and farm locations, could lead to better SOC stock inventories and analyses of how contemporary management influences SOC stock change in different ecoregions.
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Measuring and monitoring changes in soil organic C (SOC) concentrations and stocks are important for understanding ecosystem functions. Sequestration of SOC has traditionally been measured from resource‐intensive studies over extended periods of time, but an alternative approach of calculating root‐zone SOC enrichment is described here as a proxy for estimating SOC sequestration using nonlinear distribution of SOC concentration in the surface 30 cm. From literature data across 52 studies, estimated SOC concentration at 30‐cm depth was not different between pairs of conservation management and conventional‐till cropland, suggesting support for the concept of using SOC concentration at 30‐cm depth as a baseline concentration from which enrichment can be calculated. Root‐zone SOC enrichment across this ( n = 420) and an earlier study ( n = 171) was 12.0 ± 0.6 Mg C ha –1 (mean ± SE) under conventional‐till cropland ( n = 209), 16.1 ± 0.6 Mg C ha –1 under no‐till cropland ( n = 269), 20.6 ± 1.0 Mg C ha –1 under grassland ( n = 90), and 25.8 ± 3.8 Mg C ha –1 under woodland ( n = 23). Regional climatic conditions and soil texture were important in influencing baseline SOC storage and total SOC stock but were minor factors in affecting root‐zone SOC enrichment with conservation management. Root‐zone SOC enrichment is a relatively simple and straightforward calculation method to indicate SOC sequestration, and if deployed across a diversity of management and farm locations, could lead to better SOC stock inventories and analyses of how contemporary management influences SOC stock change in different ecoregions.
Measuring and monitoring changes in soil organic C (SOC) concentrations and stocks are important for understanding ecosystem functions. Sequestration of SOC has traditionally been measured from resource‐intensive studies over extended periods of time, but an alternative approach of calculating root‐zone SOC enrichment is described here as a proxy for estimating SOC sequestration using nonlinear distribution of SOC concentration in the surface 30 cm. From literature data across 52 studies, estimated SOC concentration at 30‐cm depth was not different between pairs of conservation management and conventional‐till cropland, suggesting support for the concept of using SOC concentration at 30‐cm depth as a baseline concentration from which enrichment can be calculated. Root‐zone SOC enrichment across this ( n = 420) and an earlier study ( n = 171) was 12.0 ± 0.6 Mg C ha –1 (mean ± SE) under conventional‐till cropland ( n = 209), 16.1 ± 0.6 Mg C ha –1 under no‐till cropland ( n = 269), 20.6 ± 1.0 Mg C ha –1 under grassland ( n = 90), and 25.8 ± 3.8 Mg C ha –1 under woodland ( n = 23). Regional climatic conditions and soil texture were important in influencing baseline SOC storage and total SOC stock but were minor factors in affecting root‐zone SOC enrichment with conservation management. Root‐zone SOC enrichment is a relatively simple and straightforward calculation method to indicate SOC sequestration, and if deployed across a diversity of management and farm locations, could lead to better SOC stock inventories and analyses of how contemporary management influences SOC stock change in different ecoregions.