Pesticides are widely used in agriculture, including on peat soil. The objective of this study was to analyze the effect of the application of paraquat, difenoconazole, and butylphenyl methylcarbamate (BPMC) on CO 2 emissions and concentrations of phenolic acids in a peat soil. Peat soil sample was taken in District of Pulang Pisau, Central Kalimantan. The peat soil was applied with 1.89 mg kg -1 paraquat, 1.72 mg kg -1 difenoconazole and 1.65 mg kg -1 butylphenyl methylcarbamate (BPMC), then the soil was incubated for 1, 2, 4 , 5, 7, 10, 14, 21, 26 and 30 days. The results showed that the application of pesticides on peat soil increased CO 2 emission, and decreased CH 4 emission and phenolic acid concentrations up to 30 days of incubation. The CO 2 emmisions were derived from C of degraded pesticides and from C of phenolic acids, although the oxidation reaction was not accompanied by the change of soil pH.Keyword: CO 2 emission, phenolic acids, butylphenyl methylcarbamate (BPMC), difenoconazole, paraquat, peat soil Pestisida banyak digunakan di lahan pertanian, termasuk di tanah gambut. Penelitian ini bertujuan untuk mempelajari pengaruh pestisida terhadap emisi CO 2 , dan konsentrasi asam fenolat pada tanah gambut. Contoh tanah gambut diambil dari Kabupaten Pulang Pisau, Provinsi Kalimantan Tengah. Contoh tanah tersebut diberikan pestisida dengan bahan aktif paraquat (1,89 mg kg -1 ), difenoconazole (1,72 mg kg -1 ) dan butylphenyl methylcarbamate (BPMC, 1,65 mg kg -1 ) dan selanjutnya diinkubasi di laboratorium selama 1, 2, 4, 5, 7, 10, 11, 14, 21, 26, dan 30 hari. Pemberian pestisida pada dosis anjuran selama 30 hari meningkatkan emisi CO 2 [metode titrasi], dan menurunkan emisi CH 4 . Pemberian pestisida selama 30 hari meningkatkan emisi CO 2 , dan menurunkan emisi CH 4 dan konsentrasi asam-asam fenolat di dalam tanah gambut. Emisi CO 2 berasal dari oksidasi C asam-asam fenolat dan bahan-bahan aktif pestisida, dimana reaksi oksidasi ini tidak disertai dengan perubahan pH tanah.