MIR spectroscopy for quantifying carbon storage in arid agricultural soils

Overview

This offering provides a MIR spectroscopy-based analytical approach for quantifying both soil organic carbon (SOC) and soil inorganic carbon (SIC) stocks in arid agricultural soils. The underlying research demonstrates that carbon sequestration in these systems is strongly mediated by carbonate cementations, which can either limit or enable SOC accumulation depending on land management practices such as tillage and irrigation type. By pairing spectral scanning with reference SOC and SIC measurements, the team delivers a rapid, affordable alternative to conventional wet-chemistry soil carbon analysis.

The solution is relevant for agricultural producers, soil health programs, carbon market verifiers, and land managers seeking to evaluate the climate-smart potential of arid farmland. It supports evidence-based decisions about tillage and irrigation strategies that maximize carbon storage while accounting for the unique carbonate chemistry of desert soils.

Technical specifications

Core capabilities:

• Mid-infrared (MIR) spectral scanning of soil samples to simultaneously estimate SOC and SIC stocks
• Calibration library development linking spectral signatures to measured SOC and SIC values across a range of arid agricultural management systems
• Application to samples from conventional tillage, reduced tillage, flood irrigation, and drip irrigation fields
• Validated through a preliminary study of 931 samples showing strong correlation between carbonate stocks and SOC storage, plus an agricultural study across 25 fields confirming that tillage increases SOC storage in arid systems
• Partnership with the KSSL USDA soils laboratory, providing access to established reference datasets and analytical infrastructure

Planned expansion:

• Additional 200 agricultural fields sampled at 6 samples per field (50 fields per management category)
• One-year study duration to broaden the calibration library and confirm widespread applicability across the arid southwestern United States

Technology readiness level

The MIR spectroscopy approach has been validated through published and in-preparation research, including a Nature manuscript in submission and a 931-sample modeling study. The method is currently being scaled through a collaboration with the USDA KSSL soils laboratory, with over 200 spectral scans collected in 2021 across differentially managed arid agricultural fields. The proposed expansion will refine and broaden the calibration to support broader deployment for soil carbon assessment in arid agroecosystems.