• Research in Plant Disease
• /
• v.18 no.4
• /
• pp.402-405
• /
• 2012

We surveyed the occurrence of Rice stripe virus (RSV) disease in 672 fields from 29 rice representative area in July 2012 as nationwide survey for RSV occurrence since 2008. We confirmed occurrence of virus disease in 18 areas, in west coast region including Secheon, Taean, Buwan and Cheorwon. RSV incidence rates of plant in Sacheon and Buan were less than 0.01% and 0.15%, respectively, showing similar rate with the nationwide survey carried out in 2008, whereas incidence rate of field declined from 19.9% in 2008 to 4.9% in 2012. Earlier, RSV occurred largely across the southern region of Korea. In 2001, RSV disease was found in Gangwha and Gyeonggi-do, the northern region of Korea. In 2007, RSV appeared in west coast; Buan in Jeollabuk-do and Seocheon in Choongnam-do. After migration of the vector, small brown plant hopper, from China in 2009, RSV is becoming a pandemic.

• The Korean Journal of Pesticide Science
• /
• v.15 no.2
• /
• pp.125-133
• /
• 2011

Ametryn is used in USA, China, and Japan, but not introduced in Korea yet. So, MRL (Maximum Residue Level), and analytical method of ametryn were not establishment in Korea. Therefore, this experiment was conducted to establish a determination method for ametryn residue in crops using HPLC-UVD/MS. Ametryn residue was extracted with acetone from representative samples of five raw products which comprised hulled rice, soybean, apple, green pepper, and Chinese cabbage. The extract was diluted with saline water, and dichloromethane partition was followed to recover ametryn from the aqueous phase. Florisil column chromatography was additionally employed for final clean up of the extract. The ametryn was quantitated by HPLC with UVD, using a Tosoh ODS 120T ($4.6{\times}250$ mm) column. The crops were fortified with ametryn at 2 levels per crop. Mean recovery ratio were ranged from 83.7% for a 0.2 mg/kg in soybean to 91.1% for a 1.0 mg/kg in hulled rice. The coefficients of variation were ranged from 1.2% for a 1.0 mg/kg in hulled rice to 3.6% for a 1.0 mg/kg in soybean. Quantitative limit of amatryn was 0.02 mg/kg in representative 5 crop samples. A LC/MS with selected-ion monitoring was also provided to confirm the suspected residue. Therefore, this analytical method was reproducible and sensitive enough to determine the residue of ametryne in agricultural commodities.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.58 no.1
• /
• pp.73-80
• /
• 2016

The aim of this study is to analyze the contribution of regional water resources through the gap between water used for rice production and water used for consumption. The blue water use for rice production and for consumption was quantified and the regional blue water flows were estimated using the virtual water concept from 1995 to 2010. About $1134.4Mm^3/yr$ of blue water flowed among the provinces and metropolises of Korea, and about 28.5 % of total blue water flows came from Jeonnam province. In addition, blue water usage for rice was classified into three categories: water for production, internal consumption, and overproduction in each region. In Jeonnam, $633.8Mm^3/yr$ of blue water totally used for rice production, and 50.9 % and 15.5 % were used for external and internal rice consumption, respectively. The other 33.6 % was used for over production of rice for food security. This study assumed the blue water flows depended on the gap between virtual water use for rice production and consumption. However, the analysis of regional blue water usage and flows might show the importance of other region's water resources, and make policy decision-makers aware of the integrated water management among the regions.

• Food Engineering Progress
• /
• v.23 no.4
• /
• pp.290-296
• /
• 2019

Rice in Korea is a highly valuable food resource that serves both as staple food and ingredient in various processed edibles. This study was conducted to explore pre-treatment methods for rice that result in good saccharification upon production of rice beer. When rice was subjected to fine grinding, steeping, roasting, gelatinizing, or puffing prior to saccharification with malt, wort containing puffed rice had the highest soluble solid content (°Bx). Upon production of wort without the addition of any enzymes for liquefaction or saccharification, the addition of 30% rice resulted in the highest soluble solid content (°Bx). Production of beer containing 10, 20, or 30% of either roasted or puffed rice showed that wort containing 30% puffed rice had the highest soluble solid content (15.4 °Bx) with good saccharification. The resulting beer likewise exhibited higher alcohol content (5.0-5.4%) than the beer that had roasted rice added, without the turbidity and with less bitterness. Therefore, rice puffing was considered a beneficial processing method to enhance rice saccharification and to facilitate both the production of fine quality beers and rice beer containing puffed rice.

• Korean Journal of Weed Science
• /
• v.31 no.1
• /
• pp.1-7
• /
• 2011

It was a method of weed removing, called as whagyeongsoonoobeob. Namely, the Hwanoobeob was the weeding method came from "Jeminyosool" in old China, and had been descended to "Wibinmyeongnonggi", "Nonggajibseong" and "Gwanongsocho" in the $16\sim18^{th}$ century of our country. The method was applied to rice paddy after applying direct-seeding, burning by unit before watering to remove weeds and to save rice plants. It would be applied with a method of using non-selective herbicide such as paraquat and oxyfluorfen, or radiation treatment, as a simple and safe weed removing method.

• Weed & Turfgrass Science
• /
• v.7 no.2
• /
• pp.120-129
• /
• 2018

This experiment was conducted to find the most suitable crop establishment method and weed management practices for transplanted aman rice in Bangladesh. Rice variety Bangladesh Rice Research Institute (BRRI) dhan44 was used as planting materials where three crop establishment methods ($T_1$: direct wet seeding by drum seeder; $T_2$: hand broadcasting; $T_3$: transplanting) and four weeding options ($W_1$: Hand weeding (HW); $W_2$: BRRI weeder+HW; $W_3$: Herbicide+HW; and $W_4$: no weeding) were tested. Among the crop establishment methods, the highest grain yield ($5.12t\;ha^{-1}$) was obtained with the $T_3$, while the highest benefit cost ratio (BCR) of 2.08 was found in $T_2$. In case of the weed management method, $W_1$ showed superior results on the plant $density/m^2$ (139.66) at 60 days after transplanting (DAT), grain yield ($4.97t\;ha^{-1}$), and BCR (2.03). On the other hand, the highest plant dry matter (36.20 g) at 60 DAT and the highest yield ($6.10t\;ha^{-1}$) were obtained in a $T_3W_1$ combination. The results of this study show that the productivity of rice during aman season could be most significantly increased with the use of transplanting ($T_3$) alone, hand weeding ($W_1$) alone, or a combination of the two methods ($T_3W_1$).

• International Journal of Advanced Culture Technology
• /
• v.6 no.4
• /
• pp.214-225
• /
• 2018

Rice straw is the principal forage for Korean cattle. Limited supply of domestic forage forces Korea to depend on imported forage. Utilizing locally available domestic feed as an alternative would lead to self-sufficiency and stability in cattle farm management. Locally available feed can be utilized as forage. The challenge of collecting local feed has been overcome by machines that have been developed to harvest feed. Local feed can be completely consumed in the production regions, thus reducing transportation costs and increasing price competitiveness. Hitherto, studies have focused on feed technologies and price competitiveness, among other factors, while the substitution of forage has not been examined. This study conducts a quantitative analysis to estimate the extent to which local feed can replace existing forage. We find that local feed is cheaper, and abundantly available, and can thus replace high-quality forage.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.53 no.1
• /
• pp.8-14
• /
• 2008

Ammonia ($NH_3$) volatilization from a silty clay loam paddy soil applied with non, straight urea, and coated urea, respectively, under transplanting in Milyang, Korea from 2002 and 2003 was simulated by a Water and Nitrogen Management Model (WNMM). Based on the data from the in-situ measurements, $NH_3$ volatilization during the rice growth was 6.04% and 1.46% of the applied nitrogen (N) from straight urea and coated urea, respectively. The bulk aerodynamic approach in WNMM satisfactorily predicted the difference in $NH_3$ loss during the given rice growing seasons from the two urea fertilizers. $R^2$ for the correlation between the predicted and observed NH3 loss during the calibration year (2002) was 0.53 less than 0.68 of the application year (2003). This difference could be due to the weather condition such as heavy rainfall and temperature during the calibration year.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.347-347
• /
• 2017

This study is performed to investigate the optimal cropping systems to allow cultivation of upland crops to the paddy rice land. This experiment was conducted at Anseong-si Gyeonggi province of Korea in 2015. In order to investigate growth and yield characteristics of foxtail millet, proso millet and sorghum by different paddy-upland rotation systems, three crops foxtail millet, proso millet and sorghum with four varieties of Samdachal, Samdamae, Kyeongkwan1, Hwanggeumjo in foxtail millet, Leebaekchal, Manhongchal, Hwangsilchal, Hwanggeumgijang in proso millet and Nampungchal, Moktaksusu, Aneunbangisusu, Hwanggeumchal in sorghum were examined. Four paddy-upland rotation systems of paddy-upland rotation, paddy-upland-upland rotation, paddy-upland-upland-upland rotation, and upland-paddy-upland rotation system were tested. Days from seeding to heading and ripening of foxtail millet was the shortest in the paddy-upland-upland-upland rotation system, but proso millet and sorghum did not show statistical difference among four rotation systems. In the average of culm length, paddy-upland-upland-upland rotation system showed the highest culm length in foxtail millet (141.5cm), proso millet (159.6cm) and sorghum (138.6cm) respectively among four paddy-upland rotation systems. In average yield per 10a, foxtail millet and proso millet showed the highest each 234.3kg/10a, 176.2kg/10a in paddy-upland-upland-upland rotation system, whereas sorghum was the highest 221.2kg/10a in paddy-upland-upland rotation system. The most suitable crop and varieties in paddy-upland rotation system was judged to be sorghum among three crops and suitable varieties were Samdachal in foxtail millet, Leebaekchal in proso millet and Nampungchal in sorghum respectively.

• Journal of the Korean Applied Science and Technology
• /
• v.37 no.6
• /
• pp.1678-1686
• /
• 2020

This study attempted to derive the possibility of using wood pellet using rice husk, which is an agricultural byproduct, and tried to improve the lower calorific value of rice hulls thorough expansion technology and combustion additives. In the physical and chemical analysis of rice husk, the result was obtained that the chlorine content was 0.09%, which did not meet the wood pellet quality standard of Korea. When making rice hulls into expanded rice husk through the expansion technology, the chlorine content decreased, resulting in a product of 0.02%, which is equivalent to the wood pellet standard of Korea, and the calorific value was also increased to 4,280 kcal/kg compared to the existing 3,780 kcal/kg. To obtain a product of 5,000 kcal/kg or more, borax, hydrogen peroxide, and sodium hydroxide was used as combustion improver. However the improvement in calorific value was insufficient. After conversion to coffee oil path using coffee grounds, which is a waste resource biomass, it is mixed into an expanded rice husk, and when the product is analyzed, the coffee oil 15 wt% mixed product shows an excess of 4,949 kcal/kg. When using rice husk, an agricultural byproduct, as wood pellets, it is considered desirable to use waste resources to improve the calorific value, and according to the results of this study, when mixing coffee oil, rice husk can be sufficiently used as wooden pellets.