Author(s)

Wilfredo A. Dumale Jr.^1,2*, Tsuyoshi Miyazaki², Kenta Hirai², Taku Nishimura²

¹Department of Plant Science, Nueva Vizcaya State University, Bayombong, Nueva Vizcaya, Philippines.
²Department of Biological and Environmental Engineering, University of Tokyo, Tokyo, Japan..

Agricultural liming contributes significantly to atmospheric CO₂ emission from soils but data on magnitude of lime- contributed CO₂ in a wide range of acid soils are still few. Data on lime-contributed CO₂ and SOC turnover for global acid soils are needed to estimate the potential contribution of agricultural liming to atmospheric CO₂. Using Ca¹³CO₃ (¹³C 99%) as lime and tracer, here we separated lime-contributed and SOC-originated CO₂ evolution in an acidic Kuroboku Andisol from Tanashi, Tokyo Prefecture (35°44′ N, 139°32′ E) and Kunigami Mahji Ultisol of Nakijin, Okinawa Prefecture, Japan (26°38′ N, 127°58′ E). On the average, lime-CO₂ was 76.84% (Kuroboku Andisol) and 66.36% (Kunigami Mahji Ultisol) of overall CO₂ emission after 36 days. There was increased SOC turnover in all limed soils, confirming priming effect (PE) of liming. The calculated PE of lime (Kuroboku Andisol, 51.97% - 114.95%; Kunigami Mahji Ultisol, 10.13% - 35.61%) was entirely 12C turnover of stable soil organic carbon (SOC) since SMBC, a labile SOC pool, was suppressed by liming in our experiment. Our results confirmed that mineralization of lime-carbonates is the major source of CO₂ emission from acid soils during agricultural liming. Liming can influence the size of CO₂ evolution from agricultural ecosystems considering global extent of acid soils and current volume of lime utilization. We propose the inclusion of liming in simulating carbon dynamics in agricultural ecosystems.

Agricultural Liming, Soil Organic Carbon, SOC Turnover, Andisol, Ultisol

W. Dumale Jr., T. Miyazaki, K. Hirai and T. Nishimura, "SOC Turnover and Lime-CO₂ Evolution during Liming of an Acid Andisol and Ultisol," Open Journal of Soil Science, Vol. 1 No. 2, 2011, pp. 49-53. doi: 10.4236/ojss.2011.12007.