Abstract

ABSTRACT Carbon dioxide (CO₂) monitoring has become an effective tool for assessing indoor air quality and promoting evidence-based environmental education. The aim of this study was to evaluate the impact of a pedagogical strategy based on participatory CO₂ monitoring on environmental awareness and research competencies among students from educational institutions in Sucre, Colombia. A quasi-experimental study was conducted involving 126 students from three educational institutions. Continuous measurements of CO₂, temperature and relative humidity were obtained using low-cost sensors integrated into Micro:bit platforms. Environmental knowledge tests and perception surveys were applied before and after the intervention. Significant differences were found among evaluated environments (ANOVA, p<0.001), with average CO₂ concentrations of 1,148±172 ppm in classrooms, 793±116 ppm in corridors and 612±85 ppm in green areas. Research competencies significantly improved after the intervention (Cohen's d=2.8). Furthermore, 92.1% of students reported increased awareness of the relationship between environmental quality and health. Participatory CO₂ monitoring represents an innovative educational strategy capable of promoting environmental awareness and strengthening scientific competencies among school students.   Keywords: Carbon dioxide, air quality, environmental education, citizen science, STEM education.

Abstract

Composting is an ancestral technique for managing organic waste. Recent studies show that incorporating ''Trichoderma'' spp., especially ''T. harzianum'' and ''T. viride'', significantly accelerates the decomposition of organic residues thanks to enzymes capable of degrading cellulose, chitin, and glucans. This improves the quality and nutritional value of the final compost, optimizing soil fertility and nutrient availability for crops. Therefore, implementing ''Trichoderma'' as a microbial bioactivator in compost represents a sustainable agroecological solution that strengthens soil fertility and reduces reliance on chemical fertilizers. In many rural and periurban areas, organic waste is poorly managed and there is excessive dependence on synthetic fertilizers, which degrade soil health. Inoculating compost with ''Trichoderma'' enhances compost quality—by increasing its nutritional content and biological activity—and provides biological control of pathogens, contributing to healthier and more sustainable agriculture. Composting with effective microorganisms (EM) is based on introducing beneficial microbial communities such as lactic acid bacteria, yeasts, and actinomycetes that rapidly decompose organic waste. According to Higa and Parr (1994), EM improve soil structure, increase nutrient availability, and suppress pathogenic organisms. In an agroecological approach, microbially enriched compost contributes to regenerative and resilient agricultural systems. Mycorrhizae are symbiotic associations between fungi and plant roots. These associations enhance nutrient uptake—especially phosphorus—and increase plant resistance to soil pathogens. Additionally, mycorrhizae contribute to soil structural stability and microbial biodiversity. Including them in composting can enrich soil microbiota and promote a healthier, more productive environment for plants.