To investigate the possibility of discrimination between organic and non-organic rice using stable isotope nitrogen of natural abundance, organic rice of 17 samples and non-organic rice of 13 samples grown at adjoining organic rice field were collected in 2008. Rice was grinded into brown rice, milled rice and hull, and samples were analysed for nitrogen and δ¹⁵N at NICEM. Authors also made inquiries about N source for both farmers who conduct organic- and non-organic rice cultivation. In order to know whether the δ¹⁵N can be used in discrimination between organic and non-organic rice, discriminant analysis were made with SPSS and logistic method. 1. Organic farmers used manure, rice bran, used mushroom culture, fermented fertilizer (company products), and oil cake, but non-organic farmers applied compound fertilizer. Rice straws were remained in organic rice field while moved out in non-organic field. 2. There were difference in δ¹⁵N among organic rice and its byproduct(7.760‰ in hull, 6.720‰ in rice), but significant difference was not found between them. And the trend was same between province. Non-organic rice showed similar results. 3. Significant difference of δ¹⁵N were found between organic rice and non-organic rice (p＜0.01) and between hull of organic rice and that of non-organic rice hull (p＜0.05). δ¹⁵N seemed to be useful criteria for discrimination of organic and non-organic rice. 4. When applied discrimination analysis of SPSS and logistic, there were significant difference between organic rice, non-organic rice and its byproducts except brown rice and hull in SPSS method. Hull can be used as the most useful component for unknown sample prediction with 83.3% probability.

We have studied bioremediation of effective microorganisms on crude oil spill in Taean, west-coast of Korea. Oil contaminated soil samples were collected on December 14, 2007, seven days after the Hebei Spirit oil-spilled accident. Total petroleum hydrocarbon (TPH) was measured to evaluate the effectiveness of effective microorganisms (EM) which were composed with yeast, photosynthetic bacteria and lactic acid bacteria on oil degradation. TPH concentration before EM treatment was 323.8 mg/kg, whereas TPH concentrations on 2 days after EM treatment and that of control (without EM) was 102.1 mg/kg and 170.6 mg/kg, respectively. On six days after EM treatment TPH was 91.3 mg/kg and that of control was 127.7 mg/kg. Percentages of degraded crude oil were 47.3% without EM and 68.5% with EM, 60.6% without EM and 71.8% with EM on 2 and 6 days after EM treatment, respectively. These results clearly showed that the application of effective microorganisms toward oil-contaminated soil was quite useful to degrade crude oil spill. These results were derived from the effects of biostimulation of microbial media nutrients and bioaugmentation of effective microorganisms. If we carefully apply these effective microorganisms, it can be a useful bioremediation method to recover oil-contaminated marine ecosystems.