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Agricultural liming materials are broadly utilized in the world to ameliorate soil acidity. Crushed limestone (CaCO3) and dolomite (MgCO3·CaCO3) are most common liming materials. The CO2 emission coefficient was proposed as 0.12 Mg C per Mg for CaCO3 by the Intergovernmental Panel on Climate Change (IPCC), which indicates that 100% of C in CaCO3 is eventually released to the atmosphere in the form of CO2. However, this assumption appears unlikely based on current knowledge of the very low solubility of CaCO3 and carbonate transport through soil. To develop the direct CO2 emission factor from the C-containing liming materials applied in moderately acidic soil, CaCO3 was applied in a typical temperate upland soil at different levels (0–2 Mg ha−1 yr−1), and the CO2 emission rates were determined using the closed chamber method for two years. The direct CO2 emission factor from CaCO3 was estimated using 13CO2 fluxes from 13C-CaCO3 applied soils. Approximately 0.026 Mg C per Mg of CaCO3 was emitted as CO2 from CaCO3 in cropping lands. This value was much lower than the IPCC default value (0.12 Mg C per Mg of CaCO3). The current CO2 emission coefficient was comparable with the United States Environmental Protection Agency (EPA) emission factor (0.046 Mg C per Mg of CaCO3) from the agricultural field. If the EPA emission factor from the ocean (0.013 Mg C per Mg of CaCO3) is added to the currently developed CO2 emission factor of the inner agricultural field, the total CO2 emission factor from lime may be close to 0.039 Mg C per Mg of CaCO3 in the selected upland soil. Therefore, we propose that the current IPCC guideline value of the CO2 emission factor from lime should be revised as 0.039 Mg C per Mg of CaCO3 for Korean upland soils.

Urea [(NH2)2CO] is synthesized by combining ammonia (NH3) and carbon dioxide (CO2). The consumption of atmospheric CO2 for urea production was considered carbon (C) removal by the Industrial Processes and Product Use sector. Based on this evaluation, the Intergovernmental Panel on Climate Change proposed a default value (0.2 kg C per kg urea) for the CO2 emission factor from urea, which is equivalent to the mass percent of C in urea. However, all the C in urea might not be discharged to the atmosphere during the cropping season because some bicarbonates can be released from agricultural fields. To estimate the direct CO2 emission factor, different levels of urea were applied to cultivate red pepper and garlic during the warm and cold seasons, respectively, and CO2 emission rates were monitored during the cropping seasons. The seasonal CO2 fluxes increased significantly with increasing urea application levels, reaching maximum values of 268–273 and 233-250 kg N ha−1 for red pepper and garlic, respectively, and clearly decreased thereafter. Calculated by linear regressions between urea application levels and seasonal 13CO2 fluxes originating from 13C-urea, the direct CO2 emission rates from urea were projected to be 0.062–0.063 and 0.050–0.052 kg C per kg urea for red pepper and garlic cultivation, respectively. Thus, we suggest revising the current IPCC default value (0.2 kg C per kg urea) for the CO2 emission factor from urea to be approximately 0.06 and 0.05 kg C per kg urea for warm and cold cropping seasons, respectively, in temperate upland soils.

Greenhouse-gas emission factors are widely used to estimate emissions arising from a defined unit of a specific activity. Such estimates are used both for international reporting to the United Nations Framework Convention on Climate Change (UNFCCC) and for myriad national and sub-national reporting purposes (for example, European Union Emissions Trading Scheme; EU ETS). As with the other so-called "Kyoto protocol GHGs", the Intergovernmental Panel on Climate Change (IPCC) provides a methodology for national and sub-national estimation of N₂O emissions, based on the sector from which the emissions arise. The objective of this study was to develop a integrated emission factor to estimate the direct N₂O emission from an agricultural field cultivated with the red pepper, soy bean, spring cabbage, autumn cabbage and potato in 2010∼2012. Emission factor of N₂O calculated using accumulated N₂O emission, N fertilization rate, and background N₂O emission over three year experiment was 0.00596±0.001337 kg N₂O-N (N kg) -1 . More extensive studies need to be conducted to develop N₂O emission factors for other upland crops in the various regions of Korea because N₂O emission is influenced by many factors including climate characteristics, soil properties, and agricultural practices.

Soil respiration has been recognized as a key factor of the change of organic matter and fertility due to the carbon and nitrogen mineralization. In this study, we evaluated the effect of soil respiration on the light fraction-C and inorganic N content depending on temperature in soil applied with organic matter. Soil respiration was calculated by using total CO₂ flux released from soil applied with 2 Mg ha -1 of rice straw compost and rye for 8 weeks incubation at 15, 25, 35°C under incubation test. After incubation test, light fraction and inorganic N content were investigated. Rye application dramatically increased soil respiration with increasing temperature. Q 10 value of rye application was 1.69, which was higher 27% than that of rice straw compost application. Light-C and NO₃-N contents were negatively correlated to soil respiration. Light-C in rye application more decreased than that in rice straw compost with temperature levels. These results indicate that temperature sensitivity of soil respiration could affect soil organic mater content and N availability in soil due to carbon availability. Also, light fraction would be useful indicator to evaluate decomposition rate of organic matter in soil under a short-term test.

Paddy fields comprise the single largest land use in Korea, occupying nearly 60% of arable land, consuming about 56% of the nation's water supply, and discharging a significant amount of agricultural non-point source (NPS) pollution to public waters. Rural water resources conservation, the improvement of irrigation water productivity (IWP) and the reduction of NPS pollution from paddy fields are important issues in Korea. To quantify the issue, a field-size rice-plot study was conducted for 3 years comparing the treatment of a system of rice intensification (SRI) irrigation management and a conventional practice (CT). The SRI reduced the irrigation requirement at field level by 50% compared to the CT. The IWP of the SRI improved by an average of 94% over that of the CT. The average reductions of the NPS pollutants by SRI was 44.4% (BOD), 38.6% (SS), 35.3% (CODMn), 28.3% (CODCr), 23.8% (TN) and 36.3% (TN). The SRI treatment was concluded to have contributed to healthy rice plant growth, improvement of IWP and reduction of agricultural NPS pollution from paddy fields, which could significantly conserve rural water resources and improve water quality in Korea. Copyright © 2016 John Wiley & Sons, Ltd.

Fertilization with urea can lead to a loss of carbon dioxide (CO2) that was fixed during the industrial production process. The extent of atmospheric CO2 removal from urea manufacturing was estimated by the Industrial Processes and Product Use sector (IPPU sector). On its basis, the Intergovernmental Panel on Climate Change (IPCC) has proposed a value of 0.2 Mg C per Mg urea (available in 2006 revised IPCC guidelines for greenhouse gas inventories), which is the mass fractions of C in urea, as the CO2 emission coefficient from urea for the agricultural sector. Notably, due to the possibility of bicarbonate leaching to waters, all C in urea might not get released as CO2 to the atmosphere. Hence, in order to provide an accurate value of the CO2 emission coefficient from applied urea in the rice ecosystem, the CO2 emission factors were characterized under different levels of 13C-urea applied paddy field in the current study. The total CO2 fluxes and rice grain yields increased significantly with increasing urea application (110–130 kg N ha−1) and thereafter, decreased. However, with increasing 13C-urea application, a significant and proportional increase of the 13CO2 C emissions from 13C-urea was also observed. From the relationships between urea application levels and 13CO2 C fluxes from 13C-urea, the CO2 C emission factor from urea was estimated to range between 0.0143 and 0.0156 Mg C per Mg urea. Thus, the CO2 C emission factor of this study is less than that of the value proposed by IPCC. Therefore, for the first time, we propose to revise the current IPCC guideline value of CO2 C emission factor from urea as 0.0143–0.0156 Mg C per Mg urea for Korean paddy soils.

This experiment was conducted to evaluate the effect of carbonized rice hull (CRH) application on soil carbon storage and N₂O emissions from upland soil. It was used at different rates of 0, 5, 10 and 20 Mg ㏊ -1 . During the Chinese cabbage cultivation, several soil chemical characteristics such as soil moisture, temperature and soil carbon were observed. Also, CO₂ and N₂O emissions were monitored. Soil organic matter contents slightly increased with carbonized rice hull applied in all the treatments. The soil carbon contents with application rate of 0, 5, 10 and 20 Mg ㏊ -1 were 0, 1.3, 1.2 and 2.6 g ㎏ -1 , respectively. It was observed that soil carbon content was higher with increasing CRH application rate. Total nitrogen contents of soil applied with CRH relatively decreased with the course of time. However, NO3-N contents in the soil with CRH application rate of 5, 10 and 20 Mg ㏊ -1 were 28.6, 25.7 and 21.5 ㎎ ㎏ -1 at the end of experiment, respectively. CO₂ emission at the 5 Mg ㏊ -1 application of CRH was higher about 18.9% than non-treatment, whereas those of 10Mg ㏊ -1 and 20 Mg ㏊ -1 treatment were lower 14.4% and 11.8% compared to non-treatment, respectively.Also, it was shown that N₂O emission reduced by 19.9, 28.3 and 54.0% when CRH was applied at 5, 10 and 20Mg ㏊ -1 , respectively.

Carbonized biomass could be used as a mechanism for long-term storage of C in soils. However, experimental results are variable. Objective of this study was carried out to evaluate the effect of carbonized biomass made from soybean residue on soil organic carbon and seed yield during soybean cultivation. The carbonized biomass was made by field scale mobile pyrolyzer. Pyrolyzer was performed in a reactor operated at 400~500°C for 2 hours using soybean residue. The treatments consisted of four levels as the control without input and three levels of carbonized biomass inputs as 357 kg ha -1 , C-1 ; 714 kg ha -1 , C-2 ; 1,428 kg ha -1 , C-3. It was appeared that seed yield of soybean was 2,847 kg ha -1 for control, 2,897 kg ha -1 for C-1, 2,946 kg ha -1 for C-2 and 3,211 kg ha -1 for C-3 at the end of experiment. It was shown that the contents of SOC were 5.21 g kg -1 for C-1, 5.93 g kg -1 for C-2, 7.00 g kg -1 for C-3 and 4.73 g kg -1 for the control at the end of experiment. Accumulated SOC contents linearly significantly (P -1 with every 100 kg ha -1 increase of carbonized biomass rate. Consequently the carbonized biomass for byproducts such as soybean residue could increase SOC. It might be considered that the experimental results will be applied to soil carbon sequestration for future study. More long-term studies are needed to prove how long does SOC stay in agricultural soils.

Greenhouse-gas emission factors are widely used to estimate emissions arising from a defined unit of a specific activity. Such estimates are used both for international reporting to the United Nations Framework Convention on Climate Change (UNFCCC) and for a myriad of national and subnational reporting purposes. The Intergovernmental Panel on Climate Change (IPCC) provides a methodology for national and sub-national estimation of known greenhouse gas emissions including N2O for each sector from which the emissions arise. The objective of this study was to develop an emission factor to estimate the direct N2O emission from an agricultural field cultivated with Chinese cabbage during spring season in 2010-2012. An estimated emission factor of N2O calculated over three years from field experiment accounting for cumulative N2O emission, nitrogen fertilization rate, and background N2O emission was 0.0056±0.00254 (95% CI) Kg N2O-N/kg N. More extensive studies are needed to develop N2O emission factors for other upland crops in various regions of Korea because N2O emission is influenced by many factors including climate characteristics, soil properties agricultural practices and crop species.

This experiment was carried out to find out the mitigation of greenhouse gases (GHGs) emission and changes of soil carbon contents in the cropland. In order to minimize the soil disturbance, this study was conducted without crop cultivation at the pots treated with different biomass. Different biomass was buried in the soil for 12 months. Decomposition rates of expander rice hull, pig manure compost and carbonized rice hull were 18%, 11~11.5% and 0.5~1.2%, respectively. It was appeared that carbonized rice hull was slightly decomposed. No difference was shown between chemical fertilizer treatment plot and non-application plot. It was appeared that soil carbon content in the non chemical fertilizer application plot was high when compared to its chemical fertilizer. Its content at soil depth of 20 cm more decreased than the upper layer of soil. Accumulative emission of CO₂ with different treatments of biomass was highest of 829.0~876.6 g CO₂ m -2 in the application plot of PMC (Pig Manure Compost) regardless of chemical fertilizer treatment during 16 months of experiment. However, the emission for expander rice hull treatment plot was lowest of 672.3~808.1 g CO₂ m -2 . For application plot of the carbonized rice hull, it was shown that non chemical fertilizer plot, 304.1 mg N₂O m-2, was higher than the chemical fertilizer treatment, 271.6 mg N₂O m -2 . Greenhouse gas emissions in the PMC treatment were highest of 0.94 ton CO₂ eq ha -1 yr -1 . However, it was estimated to be the lowest in the expander rice hull treatment.

Objective of this study was to investigate the effect of carbonized biomass from crop residues on chemical properties of soil and soil carbon pools during soybean cultivation. The carbonized biomass was made by field scale mobile pyrolyzer. A pot experiment with soybean in sandy loam soil was conducted for 133 days in a greenhouse, by a completely randomized design with three replications. The treatments consisted of four levels including the control without input and three levels of carbonized biomass inputs of 9.75 Mg ha -1 , C-1 ; 19.5 Mg ha -1 , C-2 ; 39 Mg ha -1 , C-3. Soil samples were collected and analyzed pH, EC, TC, TN, inorganic-N, available phosphorus and exchangeable cations of the soils. Soil pH, Total-N and available phosphorus contents correspondingly increased with increasing the carbonized material input. The contents of soil carbon pools were 19.04 Mg C ha -1 for C-1, 26.19 Mg C ha -1 for C-2, 33.62 Mg C ha -1 for C-3 and 12.01 Mg C ha -1 for the control at the end of experiment, respectively. Increased contents of soil carbon pools relative to the control were estimated at 7.03 Mg C ha -1 for C-1, 14.18 Mg C ha -1 for C-2 and 21.62 Mg C ha -1 for C-3 at the end of experiment, respectively, indicating that the soil carbon pools were increased with increasing the input rate of the carbonized biomass. Consequently, it seems that the carbonized biomass derived from the agricultural byproducts such as crop residues could increase the soil carbon pools and that the experimental results will be applied to the future study of soil carbon sequestration.

Environmental effect of water-saving irrigation on the emissions of greenhouse gases (GHGs) has not been well investigated. The objective of this study was to measure the effect of water-saving irrigation on GHGs as well as water use and rice production yield in paddy field condition in Korea. Four experimental runoff plots of 4x35 m in size were prepared at an existing paddy field. GHGs emission was measured during the 2012∼2013 growing seasons while a Japonica rice variety was cultivated. Four different water management methods, 1) Continuous Flooding (CF), 2) Intermittent Drainage (ID), 3) Water Saving (WS), and 4) CF+WS, were used during a rice growing season to compare the effects of water management methods on GHGs emission. CF method is flooding all the time, ID method makes paddy water drained 40 days after transplanting for about two weeks, WS method maintains 2~3 ㎝ water-level, which should be refilled when the water-level decreased to about 0 ㎝, and CF+WS method combines CF method before 30 days after transplanting (DAT) and WS method after 30 DAT. Regardless of water management methods, paddy field water was drained about 30 days before harvest. Amount of GHGs emission from WS plot was reduced by 69.3% compared to that from CF plot and by 59.0% compared to that from ID plot. Amount of GHGs emission from CF+WS plot was reduced by 60.7% compared to that from CF plot and by 47.5% compared to that from ID plot. Weed occurrence in CF+WS plots was reduced to 62.2% in comparison with the WS plot, implying that CF+WS plot showed the best effect to mitigation of the greenhouse gas emission in the atmosphere.

The level of nitrous oxide (N₂O), a long-lived greenhouse gas, in atmosphere has increased mainly due to anthropogenic sources, especially application of nitrogen fertilizers. Quantifying N₂O emission in the agricultural field is essential to develop national inventories of greenhouse gases (GHGs) emission. The objective of this study was to develop an emission factor to estimate the direct N₂O emission from an agricultural field cultivated with the Chinese cabbage during autumn season in 2010-2012. Emission factor of N₂O calculated over three years experiment using accumulated N₂O emission, nitrogen fertilization rate, and background N₂O emission was 0.0058±0.00254 kg N₂O-N kg -1 N. More extensive studies need to be conducted to develop N₂O emission factors for other upland crops in the various regions of Korea because N₂O emission is influenced by many factors including climate characteristics, soil properties, and agricultural practices as well as crop species.

The level of nitrous oxide (), a long-lived greenhouse gas, in atmosphere has increased mainly due to anthropogenic sources, especially application of nitrogen fertilizers. Quantifying emission in the agricultural field is essential to develop National inventories of greenhouse gases (GHGs) emission. The objective of this study was to develop emission factor to estimate direct emission from agricultural field by measuring emissions in the red pepper cultivating field from 2010 to 2012. Emission factor of calculated from accumulated emission, nitrogen fertilization rate, and background emission was N resulted from three year experiment of the research sites. More extensive studies need to be conducted to develop emission factors for other upland crops in the various regions of Korea because emission is influenced by many factors including climate characteristics, soil properties, and agricultural practices.

This study was conducted to investigate the effect of carbonized biomass from crop residues on soil carbon storage during soybean cultivation. The carbonized biomass was made by field scale mobile pyrolyzer. The treatments consisted of control without input and three levels of carbonized biomass inputs as 59.5 kg 10a -1 , C-1 ; 119 kg 10a - 1, C-2 ; 238 kg 10a -1 , C-3. Soil samples were collected during the 113 days of experimental periods, and analyzed soil pH and moisture contents. Soil carbon contents and soybean yield were measured at harvesting period. For the experimental results, soil pH ranged from 6.8 to 7.5, and then increased with increasing carbonized material input. Soil moisture contents were slightly higher by 0.1~1.5% than the control, but consistent pattern was not observed among the treatments. Soil carbon and organic carbon contents in the treatments increased at 24 and 15% relative to the control at 15 days after sowing, respectively. Loss rate of SOC (soil organic carbon) relative to its initial content was 7.2% in control followed by C-1, 6.8%> C-2, 3.5%>C-3, 1.1% during the experimental periods. The SOC change rate decreased with increasing carbonized biomass rate. It was appeared that soybean yields were 476.9 kg 10a -1 in the control, and ranged from 453.6 to 527.3, kg 10a -1 in the treatments. However, significant difference was not found among the treatments. It might be considered that the experimental results will be applied to soil carbon sequestration for future study.

This study was carried out to find out major factors to mitigate carbon emission using Life Cycle Assessment (LCA). System boundary of LCA was confined from sowing to packaging during vegetable production. Input amount of agri-materials was calculated on 2007 Income reference of white radish, chinese cabbage and chive produced at open field and film house published by Rural Development Administration. Domestic data and Ecoinvent data were used for emission factors of each agri-material based on the 1996 IPCC guideline. Carbon footprint of white radish was 0.19 kg CO₂ kg -1 at open fields, 0.133 kg CO₂ kg -1 at film house, that of chinese cabbage was 0.22 kg CO₂ kg -1 at open fields, 0.19 kg CO₂ kg -1 at film house, and that of chive was 0.66 kg CO₂ kg -1 at open fields and 1.04 kg CO₂ kg -1 at film house. The high carbon footprint of chive was related to lower vegetable production and higher fuel usage as compared to white radish and Chinese cabbage. The mean proportion of carbon emission was 35.7% during the manufacturing byproduct fertilizer; white radish at open fields was 50.6%, white radish at film house 13.1%, Chinese cabbage at outdoor 38.4%, Chinese cabbage at film house 34.0%, chive at outdoor 50.6%, and chive at film house 36.0%. Carbon emission, on average, for the step of manufacturing and combustion accounted for 16.1% of the total emission; white radish at open fields was 4.3%, white radish at film house 15.6%, Chinese cabbage at open fields 6.9%, Chinese cabbage at film house 19.0%, chive at open fields 12.5%, and chive at film house 29.1%. On the while, mean proportion of carbon footprint for the step of N₂O emission was 29.2%; white radish at open fields was 39.2%, white radish at film house 41.9%, Chinese cabbage at open fields 34.4%, Chinese cabbage at film house 23.1%, chive at open fields 28.8%, and chive at film house 17.1%. Fertilizer was the primary factor and fuel was the secondary factor for carbon emission among the vegetables of this study. It was suggested to use Heug-To-Ram web-service system, http://soil.rda.go.kr, for the scientific fertilization based on soil testing, and for increase of energy efficiency to produce low carbon vegetable.

BACKGROUND: Methane(CH 4 ) is considered as the secondmost potent greenhouse gas after carbon dioxide (CO 2 ). Methanogenesis is an enzyme-mediated multi-step process by methanogens. In the penultimate step, methylated Co-M is reduced by methyl Co-M reductase (MCR) to CH 4 involving a nickel-containing cofactor F430. The activity of MCR enzyme is dependent on the F430 and therefore, the bioavailability of Ni to methanogens is expected to influence MCR activity and CH 4 production in soil. In this study, different doses of EDTA(Ethylene Diamine Tetraacetic Acid) were applied in flooded soils to evaluate their suppression effect on methane production by chelating Ni of methanogenesis cofactor.METHODS AND RESULTS: EDTA was selected as chelating agents and added into wetland and rice paddy soil at the rates of 0, 25, 50, 75, and 100 mmol kg -1 before 4-weeks incubation test. During the incubation, cumulative CH 4 production patterns were characterized. At the end of the experiment, soil samples were removed from their jars to analyze total soil Ni and water-soluble Ni content and methanogen abundance. Methane production from 100 mmol application decreased by 55 and 78% in both soils compared to that from 0 mmol. With increasing application rate of EDTA in both soils, water-soluble Ni concentration significantly increased, but total soil Ni and methanogen activities showed negative relationship during incubation test.CONCLUSION: The decrease in methane production with EDTA application was caused by chelating Ni of coenzyme F430 and inhibiting methanogenesis by methyl coenzyme M reductase. Consequently, EDTA application decreased uptake of Ni into methanogen, subsequently inhibited Research Article Open Access

NH₄-N contents in the soil treated were relatively high in the initial stages, but rapidly decreased at 124 days after treatment. NO₃-N contents were shown to be opposite patterns of H₄-N contents. CO₂ emissions in the non-treatment and Carbonized rice hull treatment with application of NPK fertilizers decreased by 43.7 and 21.9% relative to the non-application of NPK fertilizer plot except 5.4% increasement in the pig manure compost treatment. N₂O emissions of the non-application, the Expander rice hull application, and bio-char treatment increased by 90, 25, and 21.4%, respectively, but decreased by 54.2% in the pig manure compost treatment applied with NPK fertilizers compared with the NPK fertilizer non-application plot.

To estimate greenhouse gas (GHG) emission, the inventory of rice cultivation at the farming without agricultural chemicals was established from farmers in Gunsan, Jeonbuk province in 2011∼2012. The objectives of this study were to calculate carbon footprint and analyse the major factor of GHGs. To do this, we carried out a sensitivity analysis using the analyzed main factors of GHGs and estimated the mitigation potential of GHGs. Also we suggested agricultural methods to reduce GHGs that can be appled by farmers at this region. At the farming system without agricultural chemicals, carbon footprint of rice production unit of kg was 2.15 kg CO₂.-eq. kg -1 . Although the amount of carbon dioxide (CO₂) emission was the largest among GHGs, methane (CH₄) emission had the highest contribution to carbon footprint on rice production system when it was converted to carbon dioxide equivalent (CO₂-eq.) multiplied by the global warming potential (GWP). Main source of CO₂ emission in the rice farming system without agricultural chemicals was combustion of fossil fuels used by agricultural machinery. Most of the CH₄ was emitted during rice cultivation practice and its major emission factor was flooded paddy field in anaerobic condition. Also, most of the N2O was emitted from rice cultivation process. Major sources of the N₂O emission was application of fertilizer such as compound fertilizer. As a result of sensitivity analysis in energy consumption, diesel had the highest sensitivity among the energy inputs. With the reduction of diesel consumption by 10%, it was estimated that CO₂ potential reduction was about 2.0%. With reducing application rate of compound fertilizer by 10%, the potential reduction was calculated that CO₂ and N₂O could be reduced by 0.5% and 0.9%, respectively. At the condition of 10% reduction of silicate and compost, CO₂ and CH₄ could be reduced by 1.5% and 1.6%, respectively. With 8 days more drainage than the ordinary practice, CH₄ emission could be reduced by about 4.5%. Drainage and diesel consumption were the main sources having the largest effect on the GHG reduction at the farming system without agricultural chemicals. Based on the above results, we suggest that no-tillage and midsummer drainage could be a method to decrease GHG emissions from rice production system.

Although intermittent drainage is regarded as a key factor to reduce methane (CH4) emission from paddy soil during rice cultivation, it also could increase nitrous oxide (N2O) emission. However, the effects of intermittent drainage on CH4 and N2O emissions with different global warming potential (GWP) values have not been well examined. In the present study, the effect of a 26-day intermittent drainage from the 34th day after transplanting (DAT) to the 60th DAT on two greenhouse gas (GHG) fluxes and yield properties were compared with those of a continuous flooding system under different fertilization (NPK as control, PK, and NPK+straw) during rice cultivation. The effect of intermittent drainage on changing two GHG emissions was compared using the GWP value, calculated as CO2 equivalents by multiplying 25 and 298 to the seasonal CH4 and N2O fluxes, respectively. Under the same irrigation condition, addition of nitrogen to PK significantly increased seasonal CH4 and N2O fluxes, and addition of straw to NPK increased CH4 and N2O. Irrespective with fertilization background, the intermittent drainage significantly reduced the total GWP by ca. 41–70% as affected by the big reduction of seasonal CH4 fluxes by ca. 43–53% to that of the continuous flooding even with an increase of seasonal N2O emissions by ca. 16–43%. Rice productivity was not significantly different between the two different irrigation systems under same fertilization background. As a result, total GWP per grain yield was significantly lower in all fertilization treatments with intermittent drainage compared with continuous flooding.

A field experiment with a locally-bred Japonica rice cultivar was conducted in 2011 to measure the effect of paddy irrigation management in Korea on rice yield, water use, NPS pollution discharge, and greenhouse gas (GHG) emissions. Experimental treatments were conventional paddy cultivation (CT), CT with SRI water management (CS), CT with two forced mid-season drainages (CD), and SRI methods with two different transplant spacing (SRI-30, SRI-40). Each treatment was replicated. The rice yields, selected water quality indices of the irrigation and drainage water, and GHG emissions were measured and analyzed. Irrigation water was reduced by 49.4 and 47.6 % in the SRI and CS treatments, respectively, compared with the CT treatment. Reductions in non-point source (NPS) pollution load with SRI water management ranged from 16.5 to 53.9 % in the CS plots and from 27.1 to 46.0 % in the SRI plots, depending on the water quality indices measured. The GHG emissions from the CD and CS plots when converted to CO2 equivalents were reduced by 65.5 and 72.8 %, respectively, compared with emissions from the CT plots because CH4 reduction far exceeded the N2O increase from the CD and CS plots. The two highest polished rice yields were 6.47 and 6.34 ton/ha from the SRI-30 and CS plots, respectively; these represented 20 and 17 % increase over yields from the CT plots. Trial results indicate that SRI water management in Korean paddy farming could significantly decrease the paddy irrigation requirements and also discharges of NPS pollution and GHG emissions.

A feasibility study on the system of rice intensification (SRI) methods with respect to irrigation requirements, non-point source (NPS) pollution discharge, greenhouse gas (GHG) emissions and rice yields was conducted for either 2 or 3 years depending on the treatment in Korea. Large-size runoff plots were prepared, and the necessary measuring systems installed. The SRI methods were carried out with a Japonica variety of rice, Odaebyeo (Oryza sativa L.), and the results were compared with those for control plots. The data indicated the high potentiality of adoption of the SRI methods for paddy farming in Korea. The SRI methods (i.e. SRI and conventional practice with SRI water management (CS)) reduced the irrigation requirement by 50.2 and 46.0%, respectively. For the SRI and CS plots, averaged concentration reductions of typical NPS pollutants, relative to conventional practice (CT) plots, ranged between 15.3 and 42.6%. The GHG emissions from the conventional practice with two forced drainages (CD) and the CS plots, in terms of their CO2 equivalents, were reduced by 65.5 and 72.8%, respectively, compared with those from the CT plots. The rice yields from the SRI and the CS plots were not greater than those from the CT plots. Application of SRI water management methods could help to improve Korea's water resources and water quality management, and could thus contribute to mitigation of the negative effects of global warming. Copyright © 2014 John Wiley & Sons, Ltd.

Generally, nitrogen (N) fertilization higher than the recommended dose is applied during vegetable cultivation for increasing in productivity. However, excessive N application rate beyond plant requirement could cause adverse environmental impact such as nitrate leaching and nitrous oxide emission. In this experiment, the impacts of N fertilization was studied on nitrous oxide (N₂O) emission to standardize the optimum fertilization level for minimizing of N₂O emission as well as most of the crop productivity. Herein, we assessed the N₂O emission in the flat upland soil which was cultivated with different N application rates on red pepper for 3 years (2010∼2012). N₂O emission was measured in chemical N fertilizer amounts 0 (N 0), 95 (N 0.5), 190 (N 1.0), 380 (N 2.0) kg ha-1 by using the abnormal shape chamber closed repeating three times. In average for 3 years, the total N₂O emissions of each treatment in field of soybean were 2.110 (N 0), 3.165 (N 0.5), 5.039 (N1.0), and 7.228 (N 2.0) kg N₂O ha -1 yr -1 , respectively. And then the primary regression between nitrogen fertilizer amount and the total N2O emission was showed as y = 0.0138x + 2.0942 (r 2 =0.9885), and an average of the emission factor was EF1 0.0148(0.0118∼0.0191) N₂O-N kg N -1 kg -1 from 2010 to 2012. The result was a little higher than the emission default of the IPCC 1996 Guideline (EF1 0.0125) when the results are converted into N₂O emission factor.

Under intensive vegetable production, increased productivity is primarily considered for selecting better water management and irrigation intensity in upland soils. Soil water potential at −30 kPa (field capacity) for red pepper (Capsicum annum L.) production, which is the optimum moisture potential for plants, is recommended for Korean upland soils to maximize fruit yield; however its impact on greenhouse gas (GHG) emissions have not yet been considered. In this study, red pepper was cultivated under two soil water potentials at −30 and −50 kPa by drip irrigation control in two different textured soils (clay and sandy loams). Nitrous oxide (N2O) and methane (CH4) emissions were simultaneously investigated during the cultivation period. Results indicated N2O was the main GHG and contributed to approximate 97–9% of the total global warming potential (GWP), though the extent of its contribution varied depending on soil texture and soil moisture control with emitted CH4 being negligible throughout the investigation period. Between the treatments, soil moisture control at −50 kPa was effective in reducing the emissions of the two GHGs and also increased red pepper productivity in both clay loam and sandy loam soils. Comparing the gross GWP per unit pepper fruit yield between the treatments, maintaining soil water potential at −50 kPa by controlled irrigation led to a 50% reduction of GWP per unit pepper fruit yield. Therefore, drip irrigation control to lower soil water potential at −50 than −30 kPa is recommended to obtain high crop yield and reduce GWP per unit red pepper fruit yield for red pepper production in Korea.

BACKGROUND: Methane (CH4) emission is calculated using the default CH4 emission factor as recommended by the International Panel on Climate Change(IPCC guidelines). However, the default emission factor has been derived using including the data from other countries having different soil and environmental conditions and may not reflect the real CH4 emission rates in Korea. The objective of this study was to estimate the baseline emission factor of CH4 in Korean paddy soils during rice cultivation. METHODS AND RESULTS: Methane emission patterns were characterized in four different paddy soils across country for a consecutive 3 years during the rice cultivation period. Rice plants were cultivated under continuous flooding and fertilized using the recommended chemical fertilization in Korea (N-P2O5-K2O=90-45-57kg/ha). The mean CH4 emission rate was 2.32 kg CH4/ha/day and the uncertainty of the investigated data was 21.7%, with a valuable error range at 1.82-2.82 kg CH4/ha/day with a 95% confidence interval. CONCLUSION(S): Conclusively, the Korean paddy soils' baseline emission factor of CH4 is approximately 2.32 kg CH4/ha/day and can be used to estimate the CH4 emissions more exactly.

This study was conducted to assess N₂O emissions in agricultural soils of Korea under the 1996 IPCC (Intergovernmental Panel on Climate Change) methodology. N₂O emissions in agricultural soils were calculated the sum of direct emission and indirect emission by the N sources and emissions by field burning of crop residues. N₂O emission was highest in animal manure as 1,547 CO₂-eq Gg. Indirect emissions by atmospheric deposition and leaching and runoff were 1,463 and 1,753 CO₂-eq Gg, respectively. N₂O emission by field burning of crop residues was highest in pepper due to the residue/crop ratio and field burning ratio.

The effects of water-saving irrigation on the emissions of greenhouse gases and the prokaryotic communities in rice paddy soils were investigated through a field experiment. In the Water-Saving (WS) irrigation, the water layer was kept at 2~3 cm while it was kept at 6 cm in the Continuousiy Flooding (CF) irrigation. A plot was treated with Intermittently Drainage (ID) that is drained as fine cracks on the floor were seen after transplanting. GHGs emission amounts from WS plots were reduced by 78.1% compared to that from CF plot and by 70.7% compared to that from ID plot, meaning that WS could help contribute to mitigation of the greenhouse gas accumulation in the atmosphere.

Rice cultivation in the paddy field and the burning of crop residues have been identified as the important sources of methane emission in agricultural sector. This study aimed at assessment of the methane emission from croplands in the year of 2011 with the IPCC guideline methodology. Methane from rice cultivation was emitted 6,813 CO₂-eq Gg in 2011. According to the water management, methane emission amounts by continuously flooded and intermittently flooded were 1,499 and 5,314 CO₂-eq Gg, respectively. Methane emission by crop residues burning was highest in red pepper and followed by rice straw, pulses and barely in 2011. Methane emission by field burning was very little compared with rice cultivation.

BACKGROUND: Salt accumulation in coastal reclaimed soil can decrease plant growth and productivity, which could lead to considerable variation of methane(CH4) emission in a rice paddy. The objective of this study was to evaluate the effect of salt concentration on CH4 emission in a coastal reclaimed soil. METHODS AND RESULTS: The effect of salt concentration on CH4 emission and rice growth characteristics was studied by pot test, which packed by reclaimed paddy soils collected from Galsa, Hadong, Gyeongnam province. Electrical conductivity(EC) of each treatment was controlled by 0.98, 2.25, 5.05 and 9.48 dS/m and CH4 emission was characterized a week interval by closed chamber method during rice cultivation. The CH4 emission rate was significantly decreased with increase of salt accumulation, but total CH4 flux in EC 5.50 dS/m treatment was lower than those of EC 9.48 dS/m treatment. It seems because of higher content of water soluble SO4 2- in EC 5.50 dS/m treatment than those of EC 9.48 dS/m treatment. Rice growth and grain yield were significantly decreased with increase of salt accumulation. Soil properties, especially EC and pH were negatively correlated with CH4 flux, while rice growth characteristics like plant height and tiller number show significantly positive correlation with CH4 flux. CONCLUSION(S): Conclusively, salt accumulation significantly decreased CH4 flux in a rice paddy, which could be useful information for evaluating CH4 flux in reclaimed area in Korea.

Analysis and evaluation of uncertainty is adopting the advanced methodology among the methods for greenhouse gas emission assessment that was defined in GPS2000 (Good practice guideline 2000) and GPG-LULUCF (GPG Land Use, Land-Use Change and Forestry). In 2006 IPCC guideline, two approaches are suggested to explain the uncertainty for each section with a national net emission and a prediction value on uncertainty as follows; 1) Spread sheet calculation based on the error propagation algorithm that was simplified with some assumptions, and 2) Monte carlo simulation that can be utilized in general purposes. There are few researches on the agricultural field including greenhouse gas emission that is generated from livestock and cultivation lands due to lack of information for statistic data, emission coefficient, and complicated emission formula. The main objective of this study is to suggest an evaluation method for the uncertainty of greenhouse gas emission in agricultural field by means of intercomparison of the prediction value on uncertainties which were estimated by spread sheet calculation and monte carlo simulation. A statistic analysis for probability density function for uncertainty of emission rate was carried out by targeting livestock intestinal fermentation, excrements treatment, and direct/indirect emission from agricultural lands and rice cultivation. It was suggested to minimize uncertainty by means of extraction of emission coefficient according to each targeting section.