The measurement of soil CO₂ respiration is a means to gauge biological soil fertility. Laboratory test methods for respiration vary somewhat and to date the equipment and labor required have limited more widespread adoption. This research compares results of measured soil CO₂ respiration using alkali-trap titration; Infrared gas analysis (IRGA); and the SolvitaŽ CO₂ gel system. We acquired 36 soil samples ranging in pH from 4.5-8.5 and organic C from 0.8-4.6%. All three methods were highly correlated with each other: (titration and Solvita r2=0.82, respirometer and Solvita r2=0.79 and titration vs. respirometer r2=0.95). The 24h CO2 release from all three methods was also highly correlated to both basal soil respiration (7-28 d) and cumulative 28d CO₂ respiration. An additional set of soils were acquired to examine the relationship between the CO₂ release after one day from soils amended with dairy manure compost that have been dried and rewetted, using the titration method and the Solvita system; and comparing results from water-soluble organic N, as well as C, N, and P mineralization after 28 days of incubation. Both 1-day CO2 from titration and the Solvita gel system were highly correlated with cumulative 28 day CO₂ as well as the basal rate from 7-28 days of incubation. Both methods were also highly correlated with 28 day N and P mineralization as well as the initial water extractable organic N and C concentration. The data suggest that the Solvita gel system for soil CO₂ analysis could be a simple and easily used method to quantify soil microbial activity and possibly provide an estimate of potential mineralizable N and P. Once standardized soil sampling and laboratory analysis protocols are established, the SolvitaŽ method could be easily adapted to commercial soil testing labs as an index of soil microbial activity.