The Flush of CO2 Complements Soil Health Assessment.

Health of agricultural soils depends largely on conservation management to promote soil organic matter accumulation. Total soil organic matter changes slowly, but active fractions are more dynamic. A key indicator of healthy soil is potential biological activity, which can be measured rapidly with the flush of CO₂ during 1 to 3 d following rewetting of dried soil. The flush of CO₂ is related to soil microbial biomass C and has repeatedly been shown strongly related to net N
mineralization during standard aerobic incubations. Emerging research is documenting the close association with plant dry matter production and N uptake. The flush of CO₂ following rewetting of dried soil should be considered a key indicator of soil health assessment.