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Supplemental activated biochar pellet fertilizers (ABPFs) were evaluated as a method to sequester carbon and reduce greenhouse gas (GHG) emissions, and improve rice production. The evaluated treatments were a control (standard cultivation method, no additives applied), activated rice hull biochar pellets with 40% of N (ARHBP-40%), and activated palm biochar pellets with 40% of N (APBP-40%). The N supplied by the ARHBP-40% and APBP-40% treatments reduced the need for supplemental inorganic nitrogen (N) fertilizer by 60 percent. The ARHBP-40% treatment sequestered as much as 1.23 tonne ha−1 compared to 0.89 tonne ha−1 in the control during the rice-growing season. In terms of greenhouse gas (GHG) emissions, CH4 emissions were not significantly different (p > 0.05) between the control and the ARHBP-40%, while the lowest N2O emissions (0.002 kg ha−1) were observed in the ARHBP-40% during the crop season. Additionally, GHG (CO2-equiv.) emissions from the ARHBP-40% application were reduced by 10 kg ha−1 compared to the control. Plant height in the control was relatively high compared to others, but grain yield was not significantly different among the treatments. The application of the ARHBP-40% can mitigate greenhouse gas emissions and enhance carbon sequestration in crop fields, and ABPFs can increase N use efficiency and contribute to sustainable agriculture.

Only a few have evaluated the mitigation of greenhouse emissions and profit analysis along with soil carbon sequestration for corn cultivation. This experiment was conducted to evaluate the carbon sequestration and mitigation of greenhouse gas emissions as well as their profit analysis with different composts mixed with biochar during corn cultivation. This experimental data provided the second year of corn cultivation. The soil type used was clay loam. The application amounts of synthetic fertilizer and biochar were 220–30–155 kg ha−1 (N–P–K) as the recommended amount after soil analysis and 2600 kg ha−1 based on 1.3% of soil bulk density. For the biannual experimental results, it appeared that carbon sequestration in cow manure cooperated with biochar was highest at 2.3 tons ha−1 and recovered from 67.3 to 78.5% with biochar application. Furthermore, mitigation of CO2-eq. emission as greenhouse gases was estimated to be at 7.3–8.4 MT ha−1, and its profit was evaluated from $7.2 to 8.4 as lowest, from $57.2 to 66.6 as medium and from $139.7 to 162.7 as highest per hectare regardless of organic compost types used. For agricultural practice in Korea, it is evaluated that the market price of CO2 in corn field cooperated with 2600 kg ha−1 of biochar application ranged from $57.2 to 162.7 per hectare in Korean Climate Exchange. For corn biomass, the treatment with biochar application did not significantly decrease compared with the only organic compost application. Based on these experimental results, it might be applied for carbon trading with clean development mechanism for agricultural practices.

Biomass is a renewable energy resource derived from all organic materials produced by both human and natural activities. Total biomass is amounted to be 58,010 Gg yr−1 from agricultural sector during 2013 in Korea: livestock manure, crop residues, and agro-industrial wastes. Potential methane production from agricultural biomass was calculated based on IPCC guidelines using manipulated equations. The main parameters were emission factor, total waste amount, and physico-chemical properties of each waste to estimate methane production. Calculated total potential methane production from the different categories for livestock, crop residues, and agro-industrial wastes was 502 Gg yr−1 in Korea. Poultry waste generated the highest methane potential with 227 Gg yr−1 followed by 80 Gg yr−1 from cattle waste. For crop residues and agro-industrial wastes, estimated methane production was 1 and 126 Gg yr−1, respectively. Results of this study show that livestock manure gave the highest methane emission in the agricultural sector. With this, more effective management of livestock wastes is necessary to develop and maximize technology on harnessing methane as alternative energy.

For concerning the climate change issues, the carbon sequestration and importance of soil organic matter are receiving high attention. To evaluate carbon sequestration in soil is important to determine the soil organic carbon (SOC) fractions such as WESOC (Water extractable soil organic carbon), and CO 2 emission by soil microbial respiration. However, the analyses for those contents are time-consuming procedure. There were studied the feasibility of MIRS (Mid-Infrared Spectroscopy), which has short analysis time for determining the WESOC and an incubated carbon in this study. Oven-dried soils at 100 ℃ and 350 ℃ were scanned with MIRS and compared with the chemically analyzed WESOC and cumulative carbon dioxide generated during 30, 60, 90, and 120 days of incubation periods, respectively. It was observed that an optimized determination coefficient was 0.6937 between WESOC and untreated soil processed by spectrum vector normalization (SNV) and 0.8933 between cumulative CO 2 from 30 days incubation and soil dried at 350 ℃ after subtracting air-dried soil processed by 1st derivatives. Therefore, it was shown that Quantification of soil organic carbon fractions was possibility to be analyzed by using MIRS.Keywords : soil, soil organic carbon, water extractable soil organic carbon, soil respiration, mid-infrared spectroscopy

Background: The objective of this study was to estimate the carbon sequestration in soils cooperated with organic composts and bio-char during corn cultivation. Methods and Results: For the experiment, the soil texture used in this study was clay loam, and application rates of chemical fertilizer and bio-char were 230-107-190 kg·ha-1 (N-P2O5-K2O) as recommended amount after soil test and 0.2% to soil weight. The soil samples were periodically taken at every 15-day intervals during the experimental periods. The treatments consisted of cow compost, pig compost, swine digestate from aerobic digestion system, and their bio-char cooperation. For estimating soil C sequestration, it is determined by the net balance between carbon inputs and outputs during corn cultivation periods. For the experimental results, it found that applications of aerobic swine digestate, cow compost, and pig compost could sequester C by 38.9%, 82.2% and 19.7% in soil, respectively, when bio-char from rice hulls was cooperated with soil. For plant responses, application of bio-char in the corn field for carbon sequestration was not occurred the damage of corn growth. Conclusion: When bio-char from rice hulls was cooperated with soil, applications of aerobic swine digestate, cow compost, and pig compost could sequester C by 38.9%, 82.2% and 19.7% in soil, respectively. Therefore, addition of bio-char with organic composts could have a potential soil C sequestration in agricultural practices.

Early growth, pigmentation, protein content, and phenylalanine ammonia-lyase (PAL) activity of red curly lettuces (Lactuca sativa L.) grown under different lighting conditions were investigated. Fluorescent lamps (control), blue, red, and blue plus red light-emitting diodes (LEDs) were used as light sources for 10 days. An equal proportion (1:1) of blue and red LEDs was used in the mixed radiation condition. Compared with the control, monochromic red or blue lighting increased fresh and dry weights of 'Ttuksum' and 'Jaju' lettuces. Anthocyanin synthesis was also significantly promoted by the mixed radiation of blue and red LEDs. The mixed radiation also increased the protein content and PAL enzyme activity of 'Ttuksum' leaves by about 200% compared to other treatments. Anthocyanin content was the highest in lettuces subjected to the mixture radiation of blue and red light treatment, while anthocyanin synthesis was inhibited by monochromic red light. The results of the present study indicate that growth and pigment synthesis in lettuces are significantly enhanced by exposure to mixed radiation from blue and red LEDs.

BACKGROUND: Light-emitting diodes (LEDs) with lower electric cost and the specific wavelength have been considering as a novel light source for plant production in greenhouse conditions as well as in a closed culture system. Supplementary lighting for day-length extension was considered as light intensity, light quality, and/or photoperiod control on plant growth and development. Effects of supplementary blue or red LED radiation with lower light intensity on growth of Ageratum (Ageratum houstonianum Mill., cv. Blue Field), African marigold (Tagetes erecta L., cv. Orange Boy), and Salvia (Salvia splendens F. Sello ex Ruem & Schult., cv. Red Vista) were discussed during sunrise and sunset twilight in the experiment. METHODS AND RESULTS: Supplementary lighting by blue and red LEDs for 30 (Treatment B30; R30) or 60 (Treatment B60; R60) min. per day were established in greenhouse conditions. Photosynthetic photon flux for supplementary radiation was kept at 15 μmol m-2 s-1 on the culture bed. Natural condition without supplementary light was considered as a control. The highest shoot and root dry weights were shown in African marigold exposed by red light for 60 min. per day. Supplementary blue and red lighting regardless of the radiation time significantly stimulated development of lateral branches in African marigold. Stem growth in Ageratum and Salvia seedlings was significantly promoted by red radiation as well as natural light. CONCLUSIONS: Extending of the radiation time at sunrise and sunset twilight using LEDs stimulated reproductive growth of flowering plant species. Different characteristics on growth under supplementary blue or red lighting conditions were also observed in the seedlings during supplementary radiation.

Objective of this research was to investigate the characteristics of biogas production in anaerobic digestion reactor with different mixing ratio of food waste and swine manure. It was observed that the highest removal efficiency of organic material was 80% at 60 : 40 of mixing ratio (livestock manure : food waste). And also biogas yield was varied due to different mixing ratio of them. The cumulative biogas yield was highest at 60 : 40 of mixing rate (livestock manure : food waste). For use of the liquefied fertilizer as effluent from anaerobic digester, it was the limited ratio for 30% of co-digested food waste based on its salt content.

BACKGROUND: High input to the arable land is contri-buted to increasing productivity with causing the global environmental problems at the same time. Rapeseed culti-vation has been forced to reassess its positive point for utilization of winter fallow field. The Objective of this study was performed to assess the environmental impact of rapeseed cultivation with double-cropping system in paddy rice on Yeonggwang district using life cycle assessment technique. METHODS AND RESULTS: For assessing each stage of rapeseed cultivation, it was collected raw data for input materials as fertilizer and pesticide and energy consumption rate by analyzing the type of agricultural machinery and working hours by 1 ton rapeseed as func-tional unit. Environmental impacts were evaluated by using Eco-indicator 95 method for 8 impact categories. It was estimated that 216 kg CO 2 -eq. for greenhouse gas, 3.98E-05 kg CFC-11-eq. for ozone lazer depletion, 1.78 kg SO 2 -eq. for acidification, 0.28 kg PO

BACKGROUND: Disposal of slurry animal manure produced by an anaerobic slurry-type barn method is not easy since the animal slurry contain high moisture content which makes solid-liquid separation a difficult process. However, recently, the interest about anaerobic digestion process as an environment-friendly waste disposal method has gained a wide interest because it can treat highly organic matter contained by the piggery slurry, decrease the odor after treatment, and enable the effective recovery of the methane gas which is a valuable energy resource. The objectives of this study were to identify the solubilization characteristics and to improve the anaerobic digestion efficiency of piggery slurry through full-scale anaerobic digestion experiments. METHODS AND RESULTS: In a full-scale continuous anaerobic digestion operation, the adaptability of single anaerobic digestion and its digestion efficiency were also evaluated in the farm field. The actual pH range and alkalinity concentration of piggery slurry used during the operation were comparatively higher than the concentrations of pH and alkalinity in the digestion tank which were stable at 7.5~8.0, 4,008 mg/L (as), respectively. The removal efficiency of organic matter (TCOD) by anaerobic digestion was 75~90% and methane gas production amount was at 0.33 L/L/day, a little higher than that of ordinary animal manure. CONCLUSION(s): Our findings showed higher recovery of highly purified methane and greater efficiency of anaerobic tank digestion since its methane gas content was at 65~70%.

In order to assess the performance of co-digester using pig slurry and food waste at the farm scale biogas production facility, the anaerobic facility that adopts the one-stage CSTR of 5 m 3 day -1 input scale was designed and installed under the conditions of the OLR of 2.33 kg m -3 day -1 and HRT of 30 days in an pig farmhouse. Several operation parameters were monitored for assessment of the process performance. The anaerobic facility was operated in three stages to compare the performance of the anaerobic co-digester. In the Stage I, that was fed with a mix of pig slurry to food waste ratio of 7:3 in the input volume, where input TS content was 4.7 (± 0.8) %, and OLR was 0.837-1.668 kg-VS m -3 day -1 . An average biogas yield observed was 252 Nm 3 day -1 with methane content 67.9%. This facility was capable of producing an electricity of 626 kWh day -1 and a heat recovery of 689 Mcal day -1 . In Stage II, that was fed with a mixture of pig slurry and food waste at the ratio of 6:4 in the input volume, where input TS content was 6.9 (± 1.9) %, and OLR was 1.220-3.524 kg-VS m -3 day -1 . The TS content of digestate was increased to 3.0 (± 0.3) %. In Stage III, that was fed with only pig slurry, input TS content was 3.6 (± 2.0) %, and OLR was 0.182-2.187 kg-VS m -3 day -1 . In stage III, TS and volatile solid contents in the input pig slurry were highly variable, and input VFAs and alkalinity values that affect the performance of anaerobic digester were also more variable and sensitive to the variation of input organic loading during the digester operation. The biogas produced in the stage III, ranged from 11.3 to 170.0 m 3 day -1 , which was lower than 222.5-330.2 m 3 day -1 produced in the stage II.

The current study investigated the fate of organic matter in piggery slurry under two different store systems(closed store system and open store system) in association with different temperature. Thirty days after storing in both systems at , it was observed that the content of organic matter remained in piggery slurry with closed store system was twice more than that with open store system implying more efficient degradation of organic matter with open store system. Temperature also influenced on the organic matter degradation in piggery slurry as shown decline in TS and VS contents as the temperature increased. With store at , 29% of initial organic matter was reduced while there was only 23% reduction of organic matter at . There was no difference in the type of organic fatty acids(VFAs) produced under the range of temperature(20, ) simulating summer condition. Increases in organic fatty acids contents with hydrolysis and acid producing microbial was observed from 15 days after initiating store of the piggery slurry and the total organic acid amount produced 30 days after store was and at and , respectively. These corresponded to 5.4% and 17.4% of the initial organic matter contents in piggery slurry, respectively.

Rape residue as green manure is an emerging alternative of chemical fertilizer to improve soil quality and crop productivity. Objective of this research was to evaluate the effectiveness of rape residue as green manure on reduction of chemical fertilizer and suppression of weed occurrence in rice-rape double cropping system. Greenhouse experiment was conducted with four treatments: the combination of rape residue and three different N application rates (0, 30 and 70% of recommended application rate (7.8 kg N )) and 100% chemical fertilizer as a control. No difference in rice clum length was observed for all treatments, while panicle length was highest in a treatment of rape residue+70% chemical fertilizer (Rape+70%CF). In addition, rice grain weight at a Rape+70%CF treatment increased by 19% compared to the control. This treatment also reduced weed density and biomass by 58 and 53%, respectively, compared to the control. Our results suggest that use of rape residues as green manure is an environment friendly and effective way to reduce chemical fertilizer and to enhance crop productivity in rice-rape double cropping system in Korea.

For feasibility of carbon sequestration as well as in the mitigation of greenhouse gases for application of biochar pellet, this experiment was conducted, focusing on the adsorption characteristics of NH4-N on biochar pellet mixed with different ratios of pig manure compost. For NH4-N adsorption on biochar pellets, the loading amount of biochar pellet was 211.5 mg in 50 mL of aqueous solution, and the adsorption fitted very well with Langmuir isotherm. The maximum adsorption and removal rates were 2.94 mg g−1 and 92.2%, respectively, in the pellet that contained 90% of biochar. It was also observed, by kinetic models, that NH4-N was adsorbed fast on biochar pellet with a combination ratio of 9:1 of biochar pellet/pig manure. It was further observed that the higher the amount of biochar contained in the biochar pellet, the greater the adsorption of NH4-N. For the plant response observed for lettuce, it was shown that the leaf biomass in plots treated with a 9:1 biochar/pig manure compost increased by approximately 13% compared with the leaf biomass in plots treated with the compost alone. The leaf biomass of the other treatments was higher than that of the control. This implies that the application of biochar pellets, regardless of the biochar contents, might be useful for soil carbon sequestration and greenhouse gas mitigation for agricultural practices.

For the reduction of ammonia () volatilization from the cow manure composting process, a cow manure pile was covered with vinyl (white polyethylene) and the ammonia emissions were evaluated using the dynamic chamber system for 47 days. Nitrogen and phosphorus loss from cow manure pile by rainfall was also measured in this study. In the cow manure pile without covering, the amount of emission was 0.78 N kg/Mg which accounted for 9.4% of total nitrogen contents in the cow manure. Eighty nine percent of the total emission during experimental period from the cow manure pile without covering was emitted for the first 21 days. The vinyl covering of cow manure pile reduced 91% of emission compared to the pile without covering. The amounts of nitrogen and phosphorus loss by rainfall from cow manure pile without covering were 1.27 N kg/Mg and 0.23 P kg/Mg for 47 days, respectively. Results from this study demonstrated that vinyl covering of cow manure pile could reduce emission and loss of nitrogen and phosphorus by rainfall during composting.

Manure-based composts can have detrimental effects on the agricultural lands and crops if they are applied without proper stabilization process. Composting is well-known method for the stabilization of manure-based composts and the extent of composting could be examined by maturity test. Among various methods to examine compost maturity, the performances of two mechanical methods (Solvita and CoMMe-100) were examined and the test results were compared with seed germination test. The mechanical methods are considered to be simple and relatively objective. Also they are cost- and time-efficient. Ten commercially available composts collected in Korea were used for this study. Basically, the maturity determined with these mechanical methods was in good agreement with the seed germination test. However, it appeared that the index levels of compost maturity indicated more maturity by CoMMe-100 than Solvita for the same compost. The differences between maturity index levels determined by both methods were able to be minimized through extending the reaction time for CoMMe-100 and adjusting index level for maturity determination in the standard color chart.