Greenhouse gas emission from agricultural land is recognized as an important factor influencing climatic change. In this study, the national CO2 emission was estimated for paddy soils, using soil GHG emission model (DNDC) with 1 km2 scale. To evaluate the applicability of the model in Korea, verification was carried out based on field measurement data using a closed chamber. The total national CO2 emission in 2015 was estimated at 5,314 kt CO2-eq, with the emission per unit area ranging from 2.2~10.0 t CO2-eq ha-1. Geographically, the emission of Jeju province was particularly high, and the emission from the southern region was generally high. The result of the model verification analysis with the field data collected in this study (n=16) indicates that the relation between the field measurement and the model prediction was statistically similar (RMSE=22.2, ME=0.28, and r2=0.53). More field measurements under various climate conditions, and subsequent model verification with extended data sets, are further required.

In the last 10 years, the annual number of published journal articles on biochar has increased dramatically. In addition, biochar research in South Korea has received much attention in a variety of research fields. The objectives of this study were to determine biochar research trends using bibliometric analysis methods and to suggest future research directions in South Korea. The data used in this study were compiled from online international and domestic scientific articles from 2010 to 2015. Annual production, institutes, main journal titles, research fields and frequency of keywords were analyzed to assess current research trends. As a result, biochar research in South Korea was found to be initially 10 years behind the global trend, but in 8th place globally in terms of published articles as of 2015. Future research on the long-term ecological/environmental effects of land-applied biochar and factory-scale production systems is necessary to promote practical use of biochar in South Korea.

Land application of biochar (or charcoal) has increasingly been recognized due to its favorable effect as soil amendments. However, depending upon the nature of biomass and pyrolysis condition, biochar may be rich in hazardous inorganic elements. Giant Miscanthus showed its potential as a promising source for biochar manufacture but, the risk of heavy metal leaching from Giant Miscanthus-derived biochar (GMB) has not investigated. The objective of this study was to investigate the heavy metal leachability of GMB manufactured from 3 different temperatures (400, 500, and 700oC). Elemental composition of C, N, H, S, O and 18 metals were analyzed. Leaching concentration of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn was analyzed using 4 different methods (0.1 N HCl, 1 N NH4OAc, toxicity characteristic leaching procedure, and synthetic precipitation leaching procedure). For comparison, same analysis were performed for two char materials, municipal solid waste char (MWC) and sewage sludge char (SSC), manufactured from pilot-scale muncipal waste gasification plant. Elemental composition of GMB complied with the fertilizer guideline whereas the several heavy metal content (Cd, Ni, Pb, and Zn for MWC, Cr, Cu, Ni, and Zn for SSC) was beyond the criteria. From leaching test, concentration of heavy metals from GMB was positively increased with pyrolysis temperature and the acidity of extractant solution. Leaching concentration of plant nutrients (Ca, K, and Mg) was the highest by 1N NH4OAc. Meanwhile, leaching concentration of Cu from MWC and Pb from SSC exceeded the regulatory standard of Korea and US EPA, respectively. In conclusion, with respect to the risk of heavy metals, Giant Miscanthus-derived biochar will be suitable for land application as a soil amendment, while care should be taken for using municipal waste-derived char materials.

In this study, as preliminary research for the development of natural estrogen supplement the chemical properties of Iranian black pomegranate juice concentrate and seeds were evaluated. Proximate compositions of pomegranate juice concentrate and seeds were as follows; crude lipid 0.4% and 8.2%, moisture 39.9% and 6.6%, crude protein 0.9% and 12.2%, ash 1.4% and 1.7%, and carbohydrate 42.0% and 84.5% respectively. Major amino acids are glutamic acid (1310.0ppm) and aspartic acid (896.2ppm) in juice concentrate, and glycine (611.1ppm) and arginin (401.6ppm) in seeds. Ascorbic acid has the highest concentration of 20.0mg/l00g in juice concentrate and 0.23mg/l00 in seeds. The compositions of unsaturated fatty acids such as linoleic acid and linolenic acid were higher than those of saturated fatty acids such as stearic palmitic acid. Major minerals were potassium, calcium and sodium, potassium was highest in both juice concentrate and seeds. Vitamins were composed of ascorbic acid (20.0mg/l00g), vitamin B1(0.12mg/100g) and niacin (0.80mg/l00g) in juice concentrate, and only ascorbic acid(0.23mg/l00g) in seeds. Organic acids such as citric and L-malic acid were detected only in pomegranate juice concentrate. The contents of total polyphenols were 4.55g/L in juice concentrate and 3.5mg/l00g in seeds, respectively. Phytoestrogens detected in pomegranate juice concentrate and seeds were daidzein, quercetin, genistein and 17 β-estradiol.