SOC Sequestration Rate On Long-Term Experimental Paddy and Upland Soils in Korea.

Korean agriculture has been rapidly developed for the past half a century by technical development (e.g., fertilization, mechanization, breeding). Agricultural productivity tripled from 1950's to 2000's especially in rice production. Abrupt climate change may adverse effects to agricultural production in Korea especially in rice. Elevated CO2 will increase growing season's temperature and decrease crop yield. Therefore, reducing greenhouse gases (GHGs) is crucial to sustain our production system. Soil organic carbon (SOC) is an important management factor for reducing greenhouse gases from agricultural cultivation. This study examined the effects of different management practices on SOC pool in paddy and upland soils. The experiment initiated 1975 on a research field in Gyongbuk Agricultural Research and Extension Services, Korea and plots treatment include control, NPK and compost. Paddy soils showed high SOC pool in control plot (34.8 ton/ha), in NPK plot (33.7 ton/ha), and in compost plot (35.9 ton/ha), which are 88%, 41% and 27% higher than upland soils. SOC sequestration rate were 539 kg C/ha/year for control, 400 kg C/ha/year for NPK and compost plot while SOC sequestration rate were -184 kg C/ha/year, 67 kg C/ha/year, and 99 kg C/ha/year. Results showed that long-term management of paddy soils and NPK fertilization and compost treatment could sequester SOC in paddy soils. Managing paddy soils with recommended practices could be a greenhouse gas mitigation option in Korea through SOC sequestration effectively.