Mr Songrae Cho1, Mr Piljoo Kim1,2, Mr Jeonggu Lee1, Miss Hokyung Chae1
1Gyeongsang Antional University, Jinju, South Korea, 2Institute of Agriculture and Life Sciences, Gyeongsang National University, Jinju, South Korea
Liming is a common agricultural practice worldwide, used for increasing productivity in acid agricultural soils. Liming reduces Al saturation and toxicity and/or increase pH up to values where the availability of nutrients is higher. The effort of this practice on soil properties has been extensively studied. However, liming also increase the soil biological activity, thus favoring the mineralization of organic matter, which should result in carbon dioxide (CO2) losses and a decrease of the soil organic carbon stock. From liming soil, CO2 gas was not only emitted, but also nitrous oxide (N2O) and methane (CH4). These factors could be calculated as net GWP value. However, the effect of liming on net GWP in temperate upland soil was poorly unknown. In this two-year field studies, to evaluate the effect of liming on net GWP, different levels (0,2 Mg/ha/yr) of lime were consecutively applied in a temperate upland soil before maize cultivation, and soil carbon (C) balance was analyzed using the net ecosystem C budget (NECB). The net primary production (NPP) of cash crop, weed and amendment C were considered as C input sources, and the respired C loss (CO2 – C, CH4 – C) and harvested C removal were included in C output source. Each net GWP factors are calculated as fallow as “net GWP (kg CO2-eq. ha-1) = 28 x CH4 flux (kg ha-1) + 265 x N2O flux (kg ha-1) – NECB x 44/12”. Total CH4 fluxes were not specific trend between lime application levels and years. however, total N2O fluxes were increased by liming. NECB value were decreased with liming application level. Net GWP was increased with increasing liming application level, mainly due to increased N2O flux. However, CH4’s portion was ignorable (12~24%). The largest portion was N2O’s portion (75~88%).
Pil Joo Kim got Ph. D in 1997, and has served as a professor at Gyeongsang National University, South Korea since 2001. He published over 200 peer reviewed journal articles, which focused mostly on improving soil fertility and minimizing GHG emissions. He supervised 30 MS and 19 Ph. D students. He served as the vice-chairperson of Division 2, IUSS from 2010-2014, and contributed to the success of the 20th WCSS as Editing & Academic Committee chair. He is working as a vice president at Korean Society of Soil Science and Fertilizer.
Jeunggu lee has master’s degree and ph. Degree in soil science laboratory of gyeongsang national university.