Performance of Solid-State Sensors for Continuous, Real-Time Measurement of Soil CO₂ Concentrations

Authors

Stephen L. Young, University of Nebraska - LincolnFollow
Francis J. Pierce, Washington State UniversityFollow
Jason D. Streubel, USDA-ARS, Prosser, WA
Harold D. Collins, USDA-ARS, Prosser, WA

Date of this Version

9-2009

Comments

Published in Agronomy Journal 101:1417–1420 (2009). Published online 10 Sept. 2009. doi:10.2134/agronj2009.0210N

Abstract

Recent advances in sensor technology provide a robust capability for continuous measurement of soil gases. The performance of solid-state CO₂ sensors (Model GMM220 series, Vaisala, Inc., Helsinki, Finland) was evaluated in laboratory, greenhouse, and irrigated winter wheat (Triticum aestivum L.). In ambient CO₂ concentration, the GMM222 sensor averaged 427 ± 8.3 μL L⁻¹. Under variable CO₂ concentrations, the sensor was slightly lower than concentrations measured with an infrared gas analyzer (IRGA). In greenhouse pots planted with triticale (Triticale hexaploide Lart.) and an agricultural field of irrigated winter wheat, soil CO₂ concentration exceeded the 10,000 μL L⁻¹ limit of the GMM222. Alternatively, the GMM221 sensor, designed to measure between 0 and 20,000 μL L⁻¹, showed soil CO₂ concentrations were between 14,000 and 16,000 μL L⁻¹. The GMM222 accurately measures real-time soil CO₂ concentrations under field conditions that were within the sensor detection limit. However, periods of high biological soil activity require the GMM221 sensor with a higher detection limit.