• Korean Journal of Soil Science and Fertilizer
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• v.19 no.2
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• pp.123-131
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• 1986

This study was conducted to evaluate the effect of annual application of silicate fertilizer on rice yield and soil physico-chemical properties. Field experiment was done on the condition of fertilization of silicate fert. 150 and 250kg/10a to the clay loam paddy field for ten years from 1975 to 1984. Data for rice growth and nutrient uptake was analyzed for ten years base. The results obtained are as follows. 1. Average unhulled rice yield for 10 years increased at 16% in the treat of silicate fert. 150kg/10a annually applied in comparison with the N.P.K treated plot, but silicate fert. 250kg/10a treated plot was decreasing tendency somewhat in yield. 2. Amount of potassium uptake of rice straw at the harvesting stage was positively significant recognized with unhulled rice yield and straw yield of rice plant. 3. The amounts of N, $P_2O_5$ and $K_2O$ uptake in the treat of silicate fert. 150kg/10a were much more than those of silicate fert. 250kg/10a treated plot. However the treat of silicate fert. 250kg/10a increased the amounts of CaO, MgO and Silica uptake than other treats markedly. Especially the treat of silicate fert. 150kg/10a was higher in nitrogen recovery rate than other nutrients recovery rate, but the recovery of silica was low. 4. The treat of silicate fert. 250kg/10a annually applied markedly decreased the translocation rate of nitrogen, potassium and silica from straw to the unhulled rice grain. 5. Ten years' average value of soil O.M. content was much more in the treat of silicate fert. 150kg/10a which show higher yield increase than other treats, but in the treat of silicate fert. 250kg/10a, soil O.M. content was lower, however silicate content in soil was the most among other treats.

• Korean journal of applied entomology
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• v.15 no.4 s.29
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• pp.193-197
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• 1976

Field experiments were carried out to find out effective chemicals and number and time of a chemical application for the control of the rice white-tip nematode, Aphelechoides besseyi, parasite on rice plant. Ethoprop and carbofuran were significantly effective to make increase as much as $19\%,\; or\; 260g/3.3m^2$ of unhulled grain yield. Application of carbofuran as soon as the white-tip symptom of the disease appears in field is recommended for the effective control of the disease.

• Journal of Biosystems Engineering
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• v.22 no.3
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• pp.295-302
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• 1997

An ultimate purpose of this study was to develop an automatic system for brown rice quality inspection using image processing technique. In this study emphasis was put on developing an algorithm for discriminating the brown rice kernels depending on their external quality with a color image processing system equipped with an adaptor magnifying the input image and optical fiber for oblique lightening. Primarily, geometical and optical features of images were analyzed with paddy and the various brown rice kernel samples such as a sound, cracked, peen-transparent, green-opaque, colored, white-opaque and brokens. Secondary, geometrical and optical parameters significant for identifying each rice kernels were screened by a statistical analysis(STEPWISE and DISCRIM procedure, SAS wer. 6) and an algorithm fur on- line discrimination of the rice kernels in static state were developed, and finally its performance was evaluated. The results are summarized as follows. 1) It was ascertained that the cracked kernels can be detected when e incident angle of the oblique light is less than 2$0^{\circ}C$ but detectivity was significantly affected by the angle between the direction of the oblique light and the longitudinal axis of the rice kernel and also by the location of the embryo with respect to the oblique light. 2) The most significant Parameters which can discriminate brown rice kernels are area, length and R, B and r values among the several geometrical and optical parameters. 3) Discrimination accuracies of the algorithm were ranged from 90% to 96% for a sound, cracked, colored, broken and unhulled, about 81 % for green-transparent and white-opaque and 75 % for green-opaque, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.4
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• pp.245-256
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• 1978

The effects of different particle size distribution of fused phosphate on the changes of phosphorus content in soil and plant, growth and yield of paddy rice were investigated through pot and field experiments. The following results were obtained. 1. Negative correlation was found between unhulled rice yield and the composition of fused phosphate whose particle size was larger than 28 mesh, and 65 to 150 mesh, and highly significant correlation was found between unhulled rice yield and the composition of fused phosphate whose particle size was 28 to 48 mesh. But no significant correlation was found betweeen unhulled rice yield and the composition of fused phosphate whose particle size was 48 to 65 mesh. Thus the composition of 56% of 28 to 48 mesh particles and 44% of 48 to 65 mesh particles would give the best effect. 2. In the soil of the Jeonbug series rice plant in the plots treated with fine single textured fused phosphate showed poor early growth, i.e. poor tillering and short plant height. But at harvesting stage it showed rather increased number of tillers and higher plant height. Of the composite fused phosphate the more particles of 28 to 48 mesh it had, the better growth it showed. In the soil of the Yesan series rice plant in the treated plots showed much better tillering and higher plant height in contrast with that in the control plots. Of the single textured fused phosphate the finer particles showed better growth, while of the composite fused phosphate the more particles finer than 48 mesh it had, the poorer the tillering. 3. The content of available phosphorus in the soil tended to increase as the particles of both single textured and composite phosphate became finer. The soil phosphorus content decreased as the content of phosphorus absorbed by rice plant increased at each stage of growth, and the amount of soil phophorus decreased became larger as the the particles were finer. The amount of available phosphorus in the treated soils was larger in the soil of the Yesan series than in the soil of the Jeonbug series which was a long cultivated soil and contained relatively high phosphorus. 4. In the single textured fused phosphate the amount of phosphorus absorbed by rice plant tended to increase as the particles were finer, and great difference was found at heading stage, but at harvesting stage little difference was found for all the plots. In the field experiment in the soil of the Jeonbug series more phosphorus was absorbed by rice plant in the plots treated with the composite fused phosphate of higher content of 28 to 48 mesh particles. In the pot experiment the amount of phosphorus absorbed by rice plant was highest in the plots treated with the composite fused phosphate of 53.35% of particles larger than 48 mesh and 46.6% of particles smaller than 48 mesh. In the pot experiment in the Yesan series the amount of absorbed phophorus was highest in the plots treated with the fused phosphate of 47.75% of particles larger than 48 mesh and 50. 216% of particles smaller than 48 mesh. 5. A reverse relationship was found between the absorbed phosphorus and silica. In the pot experiment in the soils of both the Jeonbug and Yesan series the amount of phosphorus absorbed by rice plant increased as the particles were finer, while the amount of absorbed silica tended to decrease.

• Applied Biological Chemistry
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• v.8
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• pp.87-93
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• 1967

1) For the micro-analysis of mercury in plant materials, the method of Furutani was shown to be the simplest and most efficient way and the recovery of the assay was about 98%. 2) When the rice grain was soaked in 1/1000 diluted solution of organo-mercury fungicide for 8 hours at the end of March, the amounts of mercury residues in the brown rice and unhulled rice were 8.8 to $9.5\;{\mu}g/g$ seeds and 10.1 to $10.7\;{\mu}g/g$ seeds, respectively. 3) By washing the treated rice seeds with running water for three days, tile residual mercury concentration was reduced to 1/4 to 1/5; thus the mercury residues were 1.86 to $1.92\;{\mu}g/g$ for brown rice and 1.96 to $2.93\;{\mu}g/g$ for unhulled rice. 4) The residual mercury was present more in the unhulled rice than in the brown rice, either before or after washing of the treated seeds. 5) Among the different rice varieties, no difference was observed in mercury residues by seed treatment and washing.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.179-185
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• 2010

To evaluate the antioxidant and antitumor potential of a newly bred rice, Hiami (Suweon-511), total polyphenol content, $\gamma$-oryzanol content, radical scavenging activities, and antitumor activities were measured (control: Ilpum). Total polyphenol contents were 6.31 and 3.75 mg/g for unhulled (UHR) and hulled rice (HR) of Hiami, which was higher than that of Ilpum (5.66 and 3.47 mg/g). The $\gamma$-oryzanol contents were 33.53 and 39.47 mg/100 g for UHR and HR of Hiami, which was higher than that of Ilpum (24.33 and 28.68 mg/100 g). DPPH radical, hydrogen peroxide, superoxide radical and hydroxyl radical scavenging activities of 70% ethanol extracts of Hiami were higher compared to Ilpum, and UHR was higher than those of HR. Antitumor activities of the 70% ethanol extracts of Hiami and Ilpum were increased with a dose-dependent manner. The extracts of Hiami have higher activities of antitumor activities on gastric and breast cancer cell lines compared to other cancer cell lines, and Ilpum has higher activities of antitumor activities on colon and liver cancer cell lines.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.182-191
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• 1999

A study was conducted for the determination of application rate of pig-dung composted with sawdust (referred as pig manure hereafter) for wetland rice. The study involved the field experiments with the cultivation of rice under different rates of application of pig manure in combination of different rates of chemical fertilizers, in a wetland rice soil. The field experiment involved following treatments : (I) Without fertilizer, (II) Standard rate of chemical fertilizers based on soil testing($98-73-71kg\;ha^{-1}$ as $N-P_2O_5-K_2O$), (III) $2.1Mg\;ha^{-1}$ of pig manure $>+80-37kg\;ha^{-1}$ of $N- K_2O$ as chemical fertilizer(Less $N-P_2O_5-K_2O$ contained in the compost), (IV) $4.2Mg\;ha^{-1}$ of pig manure+ $62-3kg\;ha^{-1}$ of $N-K_2O$as chemical fertilizer(Less $N-P_2O_5-K_2O$ contained in the compost), (V) $10Mg\;ha^{-1}$ of pig manure+ Treatment(II), (VI) $20Mg\;ha^{-1}$ of pig manure +Treatment(II). Number of tillers in treatment (I) were higher than other treatments in tillering and panicle formation stage. After heading stage, treatments (V) and (VI) have higher number of tillers, but treatment (III) and (IV) have fewer number of tillers during all growing stage. Uptake of NPK in rice plants was higher in treatment (VI), but the efficiency of N, P and K was higher in treatment (I), (III) and (IV). The yield of unhulled rice were in order of tretments (VI)>(V)>(IV)>(II)>(III), although the difference was not statistically significant. Inorganic nitrogen, available P and exchangable K contents in soil were highest at tillering stage in all treatments and became low from panicle formation to harvest stage. Available P in soil was increased by the application of pig manure upto 20 cm depth. Exchangeable cation contents in 40 to 60 cm soil depth was much higher in treatment (VI) than in other treatments. Treatment (V) and (VI) showed much higher losses of N. $P_2O_5 $ and $K_2O$ than other treatment. Though treatment (VI) tended yield higher than in other treatments, showed lodging and occurrence of leaf and neck blast in this treatment. Yield of unhulled rice in treatment (IV) was not significant statistically and reduced nutritional losses. It is conclude that treatment (IV) seems to be the most reasonable one for the application of pig manure in combination of chemical fertilizers.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.136-143
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• 2002

Emission of methane and nitrous oxide affected by nitrogen fertilizer materials were measured simultaneously in rice paddy fields under flooding and intermittent irrigation in 2000. Studies focused on mitigating $CH_4$ emission from rice paddy fields are summarized and the possibilities and limits applied to world's rice cultivation are discussed. The mitigation options are water management, soil amendments, organic matter management, different tillage, rotation, and cultivar selection. Altering water management, in particular promoting midseason aeration by short-term drainage, is one of the most promising strategies, although these practices may be limited to the rice paddy fields where the irrigation system is well prepared. The test site was divided into two water managements: a continuously flooded plot which was maintained flooded by constant irrigation from May to September, and an intermittently drained plot in which short-term (20days) draining practices were performed one times during the flooding period. By total emission of GHGs converted by global warming potential (GWP), flooding plots were higher 170$\sim$208% than interimittent irrigation plots. For emission of GHGs in fertilizer materials, it was high in the order of Swine slurry>Urea+Rice straw>Urea>LCU. Basing on GHGs emission of urea fertilization under flooding as baseline GWP of urea fertilization and Latex-coated urea under intermittent irrigation showed lower GHGs emission by 41.4% and 55.8 respectively. In this case fertilizer use efficiency (kg unhulled rice/ of applied N) were 18.2$\sim$20.2 and 18.7$\sim$19.0 and 9.3 and 5.8$\sim$6.6 for Swine slurry and LCU and Urea+Rice straw and Urea in the continuously flooded and intermittently drained plot.

• Korean Journal of Organic Agriculture
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• v.25 no.1
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• pp.203-218
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• 2017

The study was initiated at three rice paddy fields of each large-scale area environment-friendly agricultural district, Suncheon and Jangheung in Jeollanam-do, and Okcheon in Chungcheongbuk-do in 2016 to observe growth and nutrients in soil and rice in a season. Jangheung farm had two observed plots; conventional plots and conventional plots additionally fertilizing of 20% T-N with oil-cake. Soil pH, EC, and K concentration on June in Jangheung farm were significantly higher than those values observed in Suncheon and Okcheon farms. Annual rice T-N contents in the Jangheung farm were more than 80 g but decreased in a season. T-N concentration in rice was high in Jangheung farm but the concentrations of P and K were not significantly different among the three farms at harvest. Plant height was as low as 101 cm in Sunchon farm but high in the dry weight (72 g). Leaf SPAD was higher in Jangheung farm than those of other farms. Okcheon farm, with early cultivar 'Milky queen', produced high head rice of 93%, and high unhulled rice and the brown rice per ha. Therefore, the annual production income was as high as 26.7 million won per ha. However, nutrient (T-N + P + K) balance in Okcheon farm with high amount of fertilizer application were as high as 900 kg per ha. On the other hand, nutrient balance in Jangheung farm resulted in less than 300 kg.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.271-279
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• 1991

The changes in fat acidity of brown rice and eating quality of rice during long term grain storage of unhulled rice were evaluated for the government managed rices. The Tongil type rice grains had consistently significantly lower fat acidity during three and half year storage than the Japonica type rice. On sensory evaluation of the fresh milled cooked rice the eating quality of the long term stored rices, 1987, 1988, and 1989 produce Tongil did not differ much each other even though increase in fat acidity by year of storage. The Japonica rices produced in 1989 and 1990 in different locations and stored there also did not differ much in eating quality. The grains stored in storehouses of super grade did not differ significantly from those stored in the first grades, but the grains stored (4 $^{\circ}C$, RH 50%) grains have kept the eating quality almost same as the fresh grains even after two and half years. A higher degree of milling did not improve significantly the sensory taste of cooked rice of the grains long term stored.