Renewable Farming

Solvita announces a new soil CO2 respiration instrument to measure soil life

The new Biological Age in soil health and farming calls for new monitoring tools — and Solvita has come up with an easy-to-use sensor that measures soil respiration in real time. 

March 6, 2020 — Currently, the most likely users of the IRTH CO2 respirometer will be soil labs and innovative farmers keen to test soil responses to biological management techniques. We encountered the pictured instrument at the Hawkeye Farm Show booth of MidWest Bio-Tech, which markets Chandler crop products east of the Rockies. Doug Miller’s showtime featured a jar of soil with an embedded half-ear of corn to demonstrate the respiration rate of soil organisms as the digest organic matter.  This is a much simpler, real-time monitor than the usual tests such as those used by soil labs to provide a “Haney test” score for soil respiration.

MidWest Bio-Tech’s Doug Miller told us that when some of their Chandler microbial organisms are seed or soil applied, “the soil respiration rate goes up by about 25%.”

Doug Miller of MidWest BioTech, with the IRTH instrument

Here’s a partial description of the IRTH instrument extracted from the Solvita website:

“One of the main applications for IRTH® is measuring soil biological reactions. The preferred method uses fresh, moist soil to measure natural basal respiration. IRTH® can also measure disturbance events when dried, processed soils are re-moistened to produce a CO2 pulse or burst. In addition, IRTH® can measure biodegradation rate or decay in organic residues such as bio-plastics, plant litter, mixed-waste materials, food scraps and compost products. These results provide valuable information to derive a carbon loss rate or a stability index.
IRTH® offers the flexibility to conduct any of these tests with varying amounts of samples and produce results in just hours or days.

“IRTH® stores and calculates results in several fashions: It reports the internal atmospheric CO2 change during treatment, allowing you to test certain assumptions, and it calculates overall decay rate as CO2-C in relation to the original sample weight. It produces a finished, client-friendly report showing test parameters. Use IRTH® on an ongoing basis for 1-day, 3-day or 7-day runs to build a response spreadsheet for a series of treatments. No other instrument combines all of these features in such a simple, flexible and cost-effective package.”


Doug Miller says this version of the IRTH instrument is about $2,500. A farmer who’s trying to sort through the widening array of microbial soil amendments could use one of these on the farm — or his local crop consultant could do the testing on a custom basis. The instrument uses a wide-range infrared cell sensor which continually monitors CO2 in the enclosed jar, showing the level on the display. Solvita says: “With IRTH®, you can observe the influence of amendments on soil biological functions and gain a broader understanding of natural carbon reactivity, which can lead to better decision-making.”

We imagine that instrument makers will come up with other real-time tools for this purpose, although the IRTH system has a patent pending. Ongoing readings can be stored and exported into spreadsheets for analysis.

For several years, we’ve hoped to see tools like this because the widening array of “biological” products poses real challenges: What are the most cost-effective products?  Example: One of Chandler’s seed treatment products, Chandler Dry Seed Treat, is an enzyme which is only about $1 per acre for corn and typically improves early growth, resulting in 5 to 7 bu. per acre yield gains. We’re encouraging Doug Miller to do field testing using WakeUP Summer to enhance the performance of Chandler Foliar.