| 09 Feb 2026
The pH and Phosphorus Availability as Primary Drivers of Compost-Induced CO2 Emissions from Malaysian Tropical Soil: Mechanistic Evidence
Abstract. Confronting the global need for climate-smart agriculture, this study investigated the mechanisms controlling CO2 emissions from a Malaysian tropical soil amended with four composts. Multiple regression analyses identified soil available phosphorus (AP) and pH as the key interactive drivers of CO2 emissions, which followed the order: chicken dung compost (CDCS) > sludge compost (SLS) > goat manure-leaf compost (GLCS) > food waste compost (FWCS).The significantly higher emissions from CDCS were primarily due to its pronounced elevation of soil pH, likely stimulating microbial activity. The positive correlation with AP indicated that enhanced phosphorus availability further promoted microbial carbon mineralization. The findings demonstrate that compost is not a carbon-neutral amendment; its net climate impact depends on the specific physic-chemical changes it induces in the soil. This provides a scientific basis for optimizing compost selection to reconcile soil fertility improvement with greenhouse gas mitigation in tropical agroecosystems
Competing interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Chiu Chuen, Onn reports financial support was provided by Malaysia Ministry of Higher Education. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.
I have identified several errors in the references list, including incorrect author names/surnames, mismatched DOIs, and citations that cannot be verified by title or author. These inconsistencies must be thoroughly addressed and corrected if a revised version is later submitted.Â