ABSTRAKDrainase yang berlebihan dan penggunaan pupuk yang intensifdiduga menjadi penyebab tingginya emisi gas rumah kaca (GRK) padaperkebunan kelapa sawit di lahan gambut. Penelitian ini bertujuan untukmempelajari pengaruh tinggi muka air (TMA) saluran drainase, pupuk,serta amelioran terhadap emisi CO 2Â dari perkebunan kelapa sawit di lahangambut. Penelitian dilakukan dari bulan Januari 2010 sampai denganDesember 2011, pada perkebunan sawit di lahan gambut, di KecamatanSiak Kecil, Kabupaten Bengkalis, Riau, menggunakan rancangan petakterpisah, tiga ulangan. Petak utama adalah TMA saluran drainase (40, 60,dan 80 cm). Anak petak adalah pupuk dan amelioran: (1) dolomit 3kg/pohon/tahun; (2) Pugam 10 kg/pohon/tahun; (3) Pupuk dosisrekomendasi (2,5 kg urea+2,75 kg SP-36+2,25 kg KCl+dolomit 2kg)/pohon/tahun; (4) Pupuk 75% dosis rekomendasi pukan 20kg/pohon/tahun; (5) Pupuk 75% dosis rekomendasi Pugam 2,5 kg/pohon.Parameter yang diamati adalah fluks CO 2 . Hasil penelitian menunjukkanbahwa pada TMA drainase 80 cm, perlakuan dolomit menghasilkan fluksCO 2 nyata paling tinggi (142,1 t/ha/tahun) dan terendah (44,5 t/ha/tahun)dicapai perlakuan pugam. Fluks CO 2 yang tinggi (130,6 t/ha/tahun) jugadicapai perlakuan pupuk dosis rekomendasi, khususnya pada TMA 40 cm.Pada musim kemarau TMA drainase berpengaruh nyata terhadap fluksCO 2 , terendah dicapai TMA 40 cm. Oleh karena itu, untuk meminimalkanemisi gas CO 2 , maka TMA drainase perlu dipertahankan sedangkalmungkin (sekitar 40 cm) selama tidak menurunkan produksi kelapa sawit.Amelioran dengan bahan aktif kation polyvalen berpotensi dapat menekanemisi GRK dari lahan gambut yang dikelola secara intensif.Kata kunci: amelioran, emisi, drainase, gambut, kelapa sawit, pupukABSTRACTExcessive drainage and intensive use of fertilizers thought to bethe cause of high greenhouse gas emissions in peatland under oil palmplantations. The study aimed at measuring the influence of water leveldrainage (WLD), fertilizer, and ameliorant on CO 2 emissions from oilpalm plantations on peatland. The study was conducted from January2010 to December 2011, at oil palm plantation on peatland, located in SiakKecil District, Bengkalis Regency, Riau, using split plot design, with threereplications. The main plot were WLD (40, 60, and 80 cm), as sub plotswere fertilizer and amelioran: (1) dolomite 3 kg/tree/year; (2) peatfertilizer 10 kg/tree/year; (3) dose of fertilizer recommendations (2,5 kgurea+2,75 kg SP-36+2,25 kg KCl+dolomite 2 kg)/tree/year; (4) 75% doseof fertilizer recommendations + manure 20 kg/tree/year; (5) 75% dose offertilizer recommendations + peat fertilizer 2.5 kg/tree/year. Parameterobserved was CO 2 flux. The result showed that at WLD 80 cm, dolomitetreatment resulted the highest (142,1 t/ha/year) and the lowest CO 2Â flux(44,5 t/ha/year) resulted by peat fertilizer. The highest CO 2 flux alsoreached by fertilizer recommendations treatment, particularly on WLD 40cm. In dry season WLD significantly effect on CO 2 flux. The lowestreached by WLD 40 cm. Based on that the WLD needs to be maintainedin a state of shallow (approximately 40 cm), without lowering production.The use of fertilizer containing ameliorant with the polyvalen cation asactive material, potentially suppress the rate of greenhouse gas emissionsfrom peatlands are managed intensively.Key words: ameliorant, emission, drainage, peatland, oil palm, , fertilizer