Composting has emerged as a cornerstone of the circular economy and sustainable agriculture, aligning directly with the international goals for climate change mitigation and United Nations Sustainable Development Goals (SDGs). Nevertheless, the effectiveness of the composting process is highly dependent on process control. Poorly managed compost piles can lead to anaerobic conditions, producing methane (CH4) and nitrous oxide (N2O) that undermine both environmental and agricultural benefits. This study addressed the persistent limitation of discontinuous and labor-intensive compost monitoring procedures by developing and field-validating a low-cost sensor system for monitoring oxygen (O2), carbon dioxide (CO2), and methane (CH4) under tropical windrow conditions. In contrast to laboratory-restricted studies, this framework integrated rigorous calibration, multi-layer statistical validation, and process optimization into a unified, real-time adaptive design. Experimental validation was performed across three independent composting replicates to ensure reproducibility and account for environmental variability. Calibration using ISO-traceable gas standards generated linear correction models, confirming sensor accuracy within ±1.5% for O2, ±304 ppm for CO2, and ±1.3 ppm for CH4. Expanded uncertainties (U95) remained within acceptable limits for composting applications, reinforcing the precision and reproducibility of the calibration framework. Sensor reliability and agreement with reference instruments were statistically validated using analysis of variance (ANOVA), intraclass correlation coefficient (ICC), and Bland–Altman analysis. Validation against a reference multi-gas analyzer demonstrated laboratory-grade accuracy, with ICC values exceeding 0.97, ANOVA showing no significant phase-wise differences (p > 0.95), and Bland–Altman plots confirming near-zero bias and narrow agreement limits. Ecological interdependencies were also captured, with O2 strongly anticorrelated to CO2 (r = −0.967) and CH4 moderately correlated with pH (r = 0.756), consistent with microbial respiration and methanogenic activities. Nutrient analyses indicated compost maturity, marked by increases in nitrogen (+31.7%), phosphorus (+87.7%), and potassium (+92.3%). Regression analysis revealed that ambient temperature explained 25.8% of CO2 variability (slope = 520 ppm °C−1, p = 0.021), whereas O2 and CH4 remained unaffected. Overall, these findings validate the developed sensors as accurate and resilient tools, enabling real-time adaptive intervention, advancing sustainable waste valorization, and aligning with the United Nations Sustainable Development Goals (SDGs) 12 and 13.   Keywords: composting; real-time monitoring; sensor validation; greenhouse gases; sustainable agriculture

Figure 1: Compost piles during the preparation of the experimental site for composting.

Figure 2: System architecture of the modular compost-monitoring and control platform, showing the automated gas-monitoring module.

Figure 3: Normalized O2, CO2, and CH4 profiles.

Sources:

Abdulqader Ghaleb Naser, Nazmi Mat Nawi, Mohd Rafein Zakaria, Muhamad Saufi Mohd Kassim, Azimov Abdugani Mutalovich, Kamil Kayode Katibi (2025). A Real-Time Gas Sensor Network with Adaptive Feedback Control for Automated Composting Management. Sustainability 17(22), 10152

Link:

https://doi.org/

Date of Input: 31/03/2026 | Updated: 31/03/2026 | ainzubaidah