Estimation of Soil Organic Carbon (SOC) Stock in South Korea Using Digital Soil Mapping Technique

Volcanic grassland has a high soil organic carbon (SOC) stock, making it important for climate change mitigation. This study analyzed SOC stock in volcanic grassland soils and assessed the potential of volcanic grassland as a carbon sink by identifying the effect of management on SOC stock and stability. Soil samples in Jeju were collected from eight sites of generally well-managed grasslands (nominally-managed grassland, NG: applying fertilizer once annually and plant cover rate is 60 -80%), which is considered as the representative SOC stock of volcanic grassland soil. To identify whether SOC stock increased by improved management (improved grassland, IG: applying fertilizer twice annually and plant cover rate is over 80%), soil samples were collected from two IG sites. Soil samples from NG and IG were analyzed for their SOC stock and stability using SOC fractionation. Our results revealed that the SOC stock of NG was 95 ton C ha -1 . It was 19% higher than the default value (80 ton C ha -1 ) for grassland corresponding to a warm temperate climate suggested by IPCC 2006 Guidelines for National Greenhouse Gas Inventories. The SOC stock in the IG (150 ton C ha -1 ) was significantly higher than NG (95 ton C ha -1 ) by 58%. Especially, most of the increased SOC stock was stored in the stable fraction of Micro_POC (particulate organic carbon in microaggregate). Consequently, improved management of volcanic grassland in Jeju has the potential to offset 29% of carbon emissions from Jeju's agricultural sector, underlining the importance of volcanic grasslands in climate change mitigation strategies.

Section: Resultsunclassified

Section: Methodsunclassified

Assessing Soil Organic Carbon Stock and Stability in Volcanic Grasslands: Implications for Climate Change Mitigation Potential and Management Levels

Park,

Kim,

Hyun

et al. 2023

“…특히 경기 지역은 20.0 g kg -1 로 가장 낮은 유기물 함량을 나타내며, 전국 평균 유기물 함량인 29.7% 보다 낮게 나타났다 (Table 3). (Singh and Benbi, 2020;Lembaid et al, 2021;Park et al, 2021).…”

Section: Methodsunclassified

Assessing Changes in Soil Organic Matter Accumulation of Agricultural Field from 2013 to 2020 in South Korea

Lee¹,

Park

Kim³

et al. 2021

Soil organic matter (SOM) is an important indicator of soil fertility, health and quality. For proper managements of agricultural fields, a long-term monitoring of changes in SOM contents in field and estimation of national accumulation of SOM are required. In this study, SOM in agricultural fields of paddy and upland systems were investigated from 2013 to 2020 for all administrative provinces of South Korea. Total field area was decreased by 4.8% and 9.1% in 2016 and 2020, respectively, compared to 2013. In paddy field, SOM content was 27.9 g kg -1 in 2013, which was gradually increased by 1.1% in 2020. Despite that SOM content increased at a field scale, national SOM accumulation in paddy fields decreased due to reduced paddy area. In upland fields, SOM content was gradually increased by 6.5% from 2013 to 2020. Though SOM content increased, however, SOM accumulation in the total agricultural field at national scale was not affect due to less area than paddy field area. Therefore, total SOM accumulation was continuously decreased from 69.2 Tg in 2013 to 65.3 Tg in 2020 mainly due to decreasing paddy field area. This study showed that in spite of the SOM increase of both fields, national SOM accumulation is decreased with significantly decreasing total field area. Therefore, it is required to increase SOM accumulation at a field scale through proper management of SOM. In addition, it is also necessary to conserve paddy fields to enlarge agricultural SOM at national scale.

“…유기성폐자원을 활용한 바이오가스의 생산 및 이용 촉진법 (이하, 바이오가스법)이 2022년 12월에 제정되어 2023 (Park et al, 2021b;. 정책적 의사 결정에 지리정보시스템을 이용한 공간적 분포 특성의 도구로 커널밀도분석방법 (kernel density estimation)이 이용되고 있다 (Kerm, 2003;Okabe and Sugihara, 2009;Zambom and Dias, 2013).…”

Section: Introductionunclassified

Site Selection for Centralization of Pig Manure Biogas Facilities in Gyeonggi-do Using Kernel Density Analysis

Choi,

Nam,

Lee

2023

In South Korea, the standard facility capacity for bioenergy facilities is set at 100 tons per day based on livestock manure amount by bioenergy-related laws. To achieve the government's goals for the energy recovery from livestock manure, there is a need to expand and distribute centralized facilities with a capacity of 100 tons of livestock manure per day. The location and scale of these centralized facilities are influenced by the geographical location and livestock breeding scale of nearby livestock farms. The size of most domestic pig farms is small, thus it is necessary to analyze the distribution and density of medium-sized or larger livestock farms capable of supplying manure to centralized facilities. In this study, kernel density analysis and spatial density analysis were conducted to select suitable regions for centralized biogas facilities for pig manure for Gyeonggi-do. As a result of analyzing the Gyeonggi-do region as a case study, four regions in southern Gyeonggi-do and one region in northern Gyeonggi-do were estimated to be suitable regions. Although it is necessary to confirm specific suitable regions through a feasibility assessment of regions estimated to be suitable regions, it is believed that selecting candidate regions first and conducting a feasibility study through kernel density analysis will save time and help in rational decision-making.