Tracking oxygen and temperature dynamics in maize silage-novel application of a Clark oxygen electrode

• A novel method for bio-sensing aerobic deterioration in silage.
• Clark O2 sensor to simultaneously measure O2 and temperature in silage.
• Experimental results supported the proposed measurement method.

Making silage involves a complicated biochemical process where oxygen (O2) is rapidly consumed within the sealed environment leading to fermentation and stable storage of the biomass. Reintroduction of the oxygen from a leak or the feed-out process results in silage degradation. Monitoring silage O2 concentration and temperature (Tsi) can provide critical insight regarding silage quality. Thus, an in situ biosensor for simultaneous monitoring of O2 and Tsi to track silage aerobic deterioration has long been needed but was unavailable. Although the Clark oxygen electrode (COE) is traditionally applied for O2 concentration dissolved in liquids, we extended its use to the gaseous phase of silage based on Henry's law. This study tested COE's using two trials, where trial-1 explored the initial-aerobic/ensiling phase and trial-2 examined the silage feed-out phase. The experimental results of both trials demonstrated that the COE can be an important monitoring tool for assessing the O2 dynamics throughout the silage lifecycle.