Soil CO₂ respiration: Comparison of chemical titration, CO₂ IRGA analysis and the Solvita gel system

Abstract

The measurement of soil carbon dioxide respiration is a means to gauge biological soil fertility. Test methods for respiration employed in the laboratory vary somewhat, and to date the equipment and labor required have somewhat limited more widespread adoption of such methodologies. The purpose of this research is to compare the results of measured soil CO 2 respiration using three methods: (1) titration method; (2) infrared gas analysis (IRGA); and (3) the Solvita gel system for soil CO 2 analysis. We acquired 36 soil samples from across the USA for comparison, which ranged in pH from 4.5 to 8.5, organic C from 0.8 to 4.6% and the clay content from 6 to 62%. All three methods were highly correlated with each other after 24-h of incubation (titration and Solvita r 2 = 0.82, respirometer and Solvita r 2 = 0.79 and titration versus respirometer r 2 = 0.95). The 24-h (1-day) CO 2 release from all three methods was also highly correlated to both basal soil respiration (7-28 days) and cumulative 28-day CO 2 respiration. An additional 24 soil samples were acquired and added to the original 36, for a total of 60 soil samples. These samples were used for calibration of the Solvita gel digital color reader results using CO 2 -titration results and regression analysis. Regression analysis resulted in the equation y = 20.6 * (Solvita number) -16.5 with an r 2 of 0.83. The data suggest that the Solvita gel system for soil CO 2 analysis could be a simple and easily used method to quantify soil microbial activity. Applications may also exist for the gel system for in situ measurements in surface gas chambers. Once standardized soil sampling and laboratory analysis protocols are established, the Solvita method could be easily adapted to commercial soil testing labs as an index of soil microbial activity.

Soil Properties under Nitrogen‐ vs. Phosphorus‐Based Manure and Compost Management of Corn

“…Soil respiration is a reliable and useful indicator of easily decomposable organic C and an important indicator of soil quality and fertility (Haney et al, 2008;Monaco et al, 2008;Iovieno et al, 2009), and there is generally a positive linear relationship between soil respiration and SOC, with R 2 values ranging from 0.35 to 0.70 (Kaiser et al, 1992;Haney et al, 2012;Miller et al, 2014). Iovieno et al (2009) reported an increase in SOC with compost application after 3 yr and found that compost application increased soil respiration from 0.68 mg CO 2 g −1 dry weight h −1 (no compost applied) to 1.18 mg CO 2 g −1 dry weight h −1 when compost was applied at 45 Mg ha −1 yr −1 , reflecting the higher available C pool.…”

The Growth Improvement of Grammatophyllum scriptum (Lindl.) Bl. In Vitro Plantlet using Photoautotrophic Micropropagation System

“…The culture was maintained by giving continuous lighting and room temperature 25°C for eight weeks. A preliminary test on the amount of carbon dioxide that got into the culture bottle was done in accordance with Haney et al (2008).…”

The Evaluation of Hazards to Man and the Environment during the Composting of Sewage Sludge

“…The NH 4 values of the final compost indicated an immature compost in Cyl1 due to high ammonia toxicity and a sufficiently stabilised material in Cyl2. Although the Solvita© test is of a rather qualitative nature, it has been shown to correlate fairly well with other stability tests [47,50,51]. The NH 4 test results result were compatible with the difference in the SS to bulking agent ratio between the two mixtures.…”