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ARS Home » Plains Area » Temple, Texas » Grassland Soil and Water Research Laboratory » Research » Publications at this Location » Publication #423912
Research Project: Enhancing Cropping System and Grassland Sustainability in the Texas Gulf Coast Region by Managing Systems for Productivity and Resilience

Location: Grassland Soil and Water Research Laboratory

Title: Prediction and mapping of soil organic carbon stock via large datasets coupled with pedotransfer functions

Author
item DHARUMARAJAN, S - Icar - Indian Institute Of Horticultural Research
item Adhikari, Kabindra
item CHAKRABORTY, R - Icar - Indian Institute Of Horticultural Research
item KALAISELVI, B - Icar - Indian Institute Of Horticultural Research
item VASUNDHARA, R - Icar - Indian Institute Of Horticultural Research
item LALITHA, M - Icar - Indian Institute Of Horticultural Research
item HEGDE, R - Icar - Indian Institute Of Horticultural Research
item PRAKASH, H - Icar - Indian Institute Of Horticultural Research
item PARVATHY, S - Icar - Indian Institute Of Horticultural Research
item RAJESH, R - University Of Horticultural Sciences

Submitted to: Earth Science Informatics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/19/2025
Publication Date: 3/7/2025
Citation: Dharumarajan, S., Adhikari, K., Chakraborty, R., Kalaiselvi, B., Vasundhara, R., Lalitha, M., Hegde, R., Prakash, H., Parvathy, S., Rajesh, R.L. 2025. Prediction and mapping of soil organic carbon stock via large datasets coupled with pedotransfer functions. Earth Science Informatics. 18:314. https://doi.org/10.1007/s12145-025-01822-z.
DOI: https://doi.org/10.1007/s12145-025-01822-z

Interpretive Summary: Soil organic carbon (SOC) is the largest pool of sequestered carbon in soil and it's distribution and dynamics are important in land use planning and climate change mitigation strategies. This study predicted and mapped the spatial distribution of topsoil (0-15 cm) SOC and its stocks across Karnataka State in India using field measurements and state-of-the-art soil mapping techniques. Results showed that SOC in Karantaka was highly variable, and average SOC stock was 1.46 km-2. Ultisols and Mollisols had the highest and Aridisols had the lowest SOC stock. Similarly, Grassland stored the highest and agricultural lands stored the lowest SOC, respectively. The baseline SOC map derived in this study can serve as a valuable tool for land use planning and soil health and crop yield monitoring in the future.

Technical Abstract: Spatial information on soil carbon storage is crucial for informed decisions on land use planning, carbon sequestration strategies, and climate change mitigation. This study aimed to map soil organic carbon (SOC) and SOC stock for Karnataka, India (191,791 km-2) using the digital soil mapping approach. We compiled topsoil (0-15 cm) SOC data (n= 144,197) from multiple sources. Environmental covariates viz., Landsat data, topographic attributes, vegetation indices, and bio-climatic variables were used as predictors. The Quantile Regression Forest algorithm was used to predict SOC and uncertainty of prediction at 90 m spatial resolution. Two different approaches based on the data source were used for building the prediction model: Model A using all datasets (n=144,197), and Model B utilizing district-wise models (11 districts, n=139,704) with an additional model for the remaining data (n=4,493). Model B performed best with the lowest RMSE (average of 0.28%) and hence used. In addition, SOC stock was estimated using a class pedotransfer function to infer missing soil bulk density measurements, for which soil textural class map of Karnataka was predicted using the Random Forest classification algorithm and then average bulk density values for each textural class were used. Average SOC stock of Karnataka state was 1.46 ± 0.54 kg m-2, and it varied from 0.05-8.14 kg m-2. The SOC stock map can assist in facilitating state-wide land use planning, identifying priority areas for carbon sequestration strategies and in soil health and crop yield monitoring applications.