Methane Oxidation in an Intensively Cropped Tropical Rice Field Soil under Long‐Term Application of Organic and Mineral Fertilizers

• Published in: Journal of environmental quality Vol. 36; no. 6; pp. 1577 - 1584
• Main Authors: Nayak, D. R., Babu, Y. Jagadeesh, Datta, A., Adhya, T. K.
• Format: Journal Article
• Language: English
• Published: Madison American Society of Agronomy, Crop Science Society of America, Soil Science Society 01-11-2007; American Society of Agronomy
• Subjects: Alluvial soils; Bacteria; Cereal crops; Chemical Phenomena; Chemistry, Physical; Composts; Crop residues; Crops, Agricultural - metabolism; Fertilizer application; Fertilizers; Food, Organic - analysis; Green buildings; Greenhouse gases; Hydrogen-Ion Concentration; Incubation; Industrial research; Infrared radiation; Lead; Methane; Methane - metabolism; Mineral fertilizers; Minerals - pharmacology; Oryza - drug effects; Oryza - metabolism; Oryza sativa; Oxidation; Oxidation-Reduction; Oxidoreductases - metabolism; Rice; Rice fields; Soil - analysis; Soil Microbiology; Soils; Temperature; Time Factors; Tropical Climate
• ISSN: 0047-2425; 1537-2537; 1537-2537
• DOI: 10.2134/jeq2006.0501

Methane (CH4) oxidation is the only known biological sink process for mitigating atmospheric and terrestrial emissions of CH4, a major greenhouse gas. Methane oxidation in an alluvial soil planted to rice (Oryza sativa L.) under long‐term application of organic (compost with a C/N ratio of 21.71), and mineral fertilizers was measured in a field‐cum‐laboratory incubation study. Oxidation rates were quantified in terms of decrease in the concentration of CH4 in the headspace of incubation vessels and expressed as half‐life (t½) values. Methane oxidation rates significantly differed among the treatments and growth stages of the rice crop. Methane oxidation rates were high at the maximum tillering and maturity stages, whereas they were low at grain‐filling stage. Methane oxidation was low (t½ = 15.76 d) when provided with low concentration of CH4 On the contrary, high concentration of CH4 resulted in faster oxidation (t½ = 6.67 d), suggesting the predominance of “low affinity oxidation” in rice fields. Methane oxidation was stimulated following the application of mineral fertilizers or compost implicating nutrient limitation as one of the factors affecting the process. Combined application of compost and mineral fertilizer, however, inhibited CH4 oxidation probably due to N immobilization by the added compost. The positive effect of mineral fertilizer on CH4 oxidation rate was evident only at high CH4 concentration (t½ = 4.80 d), while at low CH4 concentration their was considerable suppression (t½ = 17.60 d). Further research may reveal that long‐term application of fertilizers, organic or inorganic, may not inhibit CH4 oxidation.