• KOREAN JOURNAL OF CROP SCIENCE
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• v.10
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• pp.61-71
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• 1971

This study was conducted in order to investigate the effects of slaked lime and borax on the Akiochi paddy field. The pot trial(slaked lime was treated 0, 6, 10, 15g and borax 0, 0.75, 1.5g per pot) and the field trial(slaked lime was treated 0, 100, 200kg and borax 0, 10, 30, 50kg per 10are) respectively. The results are summarized as fo11ows. I. Pot Trial: 1. In a heavy treated of borax, appeared chlorosis on whole leaves(bottom) in early growing stage, However, in about 25 days after transplanting, these chlorosis were disappeared gradually. And in proportion to close by maturity after the ear-heading, changed to dark brown color and rolled at the end of upper leaves, finally withered. At the same time the part of the end of grains was also colored to dark brown. 2. Slaked lime effected to increase the ti1lering, hence increased the number of ear, on the other hand, borax showed the tendency of repression the tillering, conversely. 3. Borax effected to hurried up to heading date of rice plant, to which borax had been the plot of B$_1$ to 3 days and B$_2$ to 5 days, hurried up than control respectively, regardless of the quantities of slaked lime application. 4. According to the application of borax, the length of culm were shortened, otherwise the length of panicle were longished, then no recognized the. independent effect of slaked lime. 5. The number of grains per panicle were seemed like increased by treatment of slaked lime, but the grain were decreased in the heavy treatment of slaked lime and borax. These phenomena were showed in ratio of maturity likely tendency as above. 6. In the 1, 000 grains weight of brown rice, in the case of slaked lime was almost no significant, otherwise by increase the application of borax, increased the weight of 1, 000 grains and the size of the grains was greater. 7. The weight of rough rice and straw were showed the same tendency as the number of grains and maturity ratio. particularly, showed the phenomenon of the reduction by the heavy application of borax. II. Field trial: 1. In a heavy treated of borax, appeared chlorosis in a early growing stage, according to close by maturiting date after the ear-heading changed to dark brown the end of upper leaves, finally dried. 2. Slaked lime application accelerated the growth and increased the number of ear, but borax showed the tendency of repression the tillering. 3. Borax effected to hurried up to heading date of rice plant, according to heavy treatment of borax quickened heading date for 4 to 5 days. 4. As a whole, culm length was repressed by borax treatment. 5. Borax application 10kg per 10are advanced progress the maturity, but in the case of above 30kg per 10are of borax showed the tendency obstruction the maturity. 6. The yield of rough rice and brown rice recognized the independent effect of slaked lime and borax, respectively. the yield was decreased by the abundant of borax.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.666-672
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• 1997

Twenty years' daily mean air temperature data was used to calculate the critical early seeding date(CESD), the optimum heading date(OHD), the critical late heading date for stable ripening(CHDR) and the critical late ripening date(CLRD) for rice seeded on dry paddy in different agroclimatic zones in Korea. The CESD was defined as the first day with mean air temperature of 13$^{\circ}C$, and the OHD as the first day of the 40 consecutive days with mean air temperature of 22$^{\circ}C$ or above after heading. The CHDR was defined as the date after which the cumulative daily mean air temperature would be at least 76$0^{\circ}C$. Lastly, the CLRD was defined as the last day when daily mean air temperature remains above 15$^{\circ}C$. This information was used for the estimation of periods from the earliest date of seeding to optimum heading date, the latest possible date of heading and the latest possible date of ripening in respective regions. For instance, in Suwon, those respective periods mentioned were found to be 104days, 124days, and 165days.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.275-284
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• 2017

Rice quality should be considered as a primary consumer requirement. Regarding marketing, characteristics such as appearance, physicochemical properties, and palatability of brand rice are of high economic importance. Therefore, this study was conducted to select the optimal rice cultivars representing the commercial rice brands of Gyeongsangbuk-do province in Korea. Various rice grain quality components, grain appearance, several physicochemical properties of rice grain, and texture or palatability of cooked rice grains of ten cultivars (namely 'top quality rice') cultivated at three different locations, such as inland mountainous and southern plain areas of Gyeongsangbuk-do province in 2013~2014, were evaluated, and the obtained data was analyzed. 'Hiami' showed slightly higher protein contents and lower palatability of cooked rice than the other rice cultivars. Rice production and head rice yield produced at Gumi were the highest. The protein content of milled rice produced at Andong, an inland mountainous region, was approximately 0.3% point lower than that from other locations, whereas the amylose content of milled rice was approximately 1% point higher than those from the other plain regions, Daegu and Gumi. We evaluated the texture, Glossiness value determined using a Toyo teste meter and palatability of cooked rice of ten cultivars. The hardness of cooked rice produced in Andong was slightly lower than that produced in Daegu and Gumi, and additionally, the palatability of cooked rice produced in Andong was the best, followed by that producted in Gumi and Daegu. Considering rice yield and grain quality in the major rice cultivation areas of Gyeongsangbuk-do province, the rice cultivars that may be suitable for each region could be recommended mid-late maturation: 'Younghojinmi' and 'Mipum' in Daegu, 'Daebo', 'Samgwang', Chilbo' and 'Younghojinmi' in Gumi, 'Samgwang', 'Jinsumi' and 'Sukwang' in Andong. These results obtained in this study imply that the selected cultivars with high yield and quality could be recommended with high priority to rice farmers in the regions.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.394-398
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• 1997

Changes of nutrient material and heavy metals of irrigation water and natural supplies by irrigation water into 1.0ha of paddy field during the rice cultivation was investigated pH of irrigation water ranged 6.458.34 and electrical conductivity showed $110{\mu}S/cm$ in the first irrigation period and commonly showed $90{\mu}S/cm$. The content of T-N, NH4-N and $NO_3-N$were 3.09~12.36, 0.17~1.34 and 2.70~10.72mg/L respectively. The content of T-P was 0.09~0.22mg/L and ortho-P was not detected. The content of $Ca^{++},\;Mg^{++},\;Na^+\;and\;K^+$ showed 0.89~5.12, 1.12~2.76, 1.74~4.52 and 1.34~4.18mg/L regardless of irrigation season respectively. Only Cu and Zn of heavy metals were detected 0.001~0.009 and 0.007~0.091mg/L, but Pb, Cd, Cr and Ni were not detected When supplied $4,250m^3$ of an irrigation water into 1.0㏊ of paddy field, natural supplies of nutrient materials were 29.67㎏ of T-N, 1.80㎏ of $NH_4-N$, 24.57kg of NO3-N and 0.51kg of T-P. Also $Ca^{++},\;Mg^{++},\;Na^+,\;K^+,\;Cl^-\;and\;SO_4\;^{2-}$ were supplied 9.42, 7.09, 13.34, 9.08, 40.27 and 41.38kg respectively. Only Cu and Zn of heavy metals were supplied 0.017kg of Cu and 0.133kg of Zn, Pb, Cd, Cr and Ni were not supplied

• Research in Plant Disease
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• v.14 no.1
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• pp.21-25
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• 2008

This study was conducted to decide disease incidence level of rice leaf blast required for reasonable fungicide application in paddy field. We induced the disease development by inoculating rice blast pathogens on rice seedlings (Jinmibyeo) in the greenhouse and transplanting the infected seedlings in the field two weeks after rice plants were transplanted. We scored the disease incidence, grouped and marked according to degree of percentage of diseased leaf area at maximum stage of disease development. The percent diseased leaf area (PDLA) had negative correlations with panicle number per hill, ripened grain (%), and total yield; their correlation coefficients (r), $-0.97^{**}$, $-1.00^{**}$ and $-0.96^{**}$, respectively. However, it had positive correlations with spikelets per panicle and thousand grain weight; their correlation coefficients (r), $0.98^{**}$ and $0.98^{**}$, respectively. Gain threshold (GT) calculated based on control cost and market price was estimated to be 8.35. Economic injury level (EIL) obtained based on GT and coefficient of damage of regression equation between disease incidence and the different yield components; panicle number per hill, spikelets per panical, ripened grain(%), thousand grain weight and yield were 41.8, 9.7, 19.1, 291.1 and 3.4%, respectively. Economic threshold (ET) for yield was 2.7% ($3.4%(EIL){\times}0.8$) on PDLA. These results suggest that application of fungicide is necessary when two under leaves are almost covered with lesions or contained more than twenty large lesions under leaves at maximum tillering stage.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.6
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• pp.352-360
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• 2002

This study was carried out to find out the effect of Milk vetch(Astragalus sinicus L.) on growth, and yield of rice, physicochemical properties of soil, reduction rate of nitrogen fertilization, and soil improvement under the different plowing time with Milk vetch cultivated in paddy field, plowing at maximum blooming, last blooming, fruiting stages. The fresh weight of Milk vetch at each plowing time of maximum blooming, last blooming and fruiting stage was 22,500, 20,000, $12,500kg\;ha^{-1}$ respectively. Content of total nitrogen at three plowing times was 2.95, 2.66, and 2.47% and the C/N ratio were 15.7, 18.0, and 19.2, respectively. Physico-chemical properties of soil were improved in cultivated milk vetch, the content of T-N. OM and porosity ratio were increased while the content of $P_2O_5$ and bulk density, solidphase ratio were decreased compared to noncultivated milk vetch. Content of $NH_4-N$ in soil was highest plowing at maximum blooming stage and appeared an increasing tendency according to increased nitrogen level. Amount of nitrogen fertilizer by rice was highest plowing at maximum blooming stage and appeared an increasing tendency according to increased nitrogen level. Nitrogen-use efficiency was high in $33kg\;ha^{-1}$ nitrogen level at three plowing times. The number of spikelets per $m^2$ was high in plowing at maximum blooming stage, last blooming stage and the percentage of ripeness was high in fruiting stage of milk vetch. So the rice yield was increased 9%, 8% in $55kg\;ha^{-1}$ nitrogen level plowing at maximum blooming stage, last blooming stage and 1% in $77kg\;ha^{-1}$ nitrogen level plowing at fruiting stage compared to conventional cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.2
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• pp.100-108
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• 2000

High sodium contents in food-waste compost(FWC) is the greatest limitation to recycle it to arable lands in Korea. The effects of the FWC application to paddy soil on the growth of rice plants, cationic balance in plants, and the sodicity of soil have been studied in pot trials. The effects of FWC application were compared with those of NaCl compound and swine manure compost(SMC) application. $Na_2O$ contents of FWC were high as 2.2%. Immediately after transplanting, rice plants in three treatments showed severe wilting in the order of 40Mg FWC $ha^{-1}$ > NPK+900kg $NaClha^{-1}$ > 20Mg FWC $ha^{-1}$. The high EC value and volatile acid contents of soil solution were regarded as the cause of severe wilting of young rice plants. Increase of NaCl application rate upto $900kgha^{-1}$ showed no significant reduction of dry matter yield at harvesting stage. Regardless of application rates FWC reduced the dry matter yield at harvesting stage, while SMC increased it with increase of application rates upto $40Mgha^{-1}$. In NPK+NaCl and FWC treatments, Na contents and equivalent ratio in plants increased linearly with increase of Na application rates. Between Na and K equivalent ratio negative correlation with high significance was shown. In contrast to much difference of Na, K, and Na/K equivalent ratio among treatments, little difference of Na+K indicated the physiological substitution of Na for K in rice plants. Na use efficiency in NPK+NaCl and FWC treatments showed 12-22%.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.333-343
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• 2003

This experiment was carried out to improve the utilization of liquid pig manure (LPM) for rice at the two textures of valley soil in 2000 and 2001. The soil textures were coarse loamy and fine loamy in Sachon and Jisan series, respectively. Treatments consisted of no fertilized plot, chemical fertilized plot, LPM 150%, LPM 100%, LPM 100%+NK (top dressing) 30%, LPM 70%+NK 30%, LPM 50%+NK 50% plot. LPM was applied as basal fertilizer compare to nitrogen of chemical fertilized plot. Total N contents in the LPM were 6.0 and $4.5g\;kg^{-1}$ in 2000 and 2001, respectively. After the experiment, P and K contents of soils were not difference between chemical and LPM application plots. But heavy metal contents in soils were slightly higher in LPM application plots than in chemical fertilized plot. Immediately after LPM application, ammonia gas content was $18mg\;kg^{-1}$ in LPM 150% plot, but it was $3mg\;kg^{-1}$ in LPM 50% plot. Two days after LPM application, ammonia gas content was 3 times higher in coarse loamy than in fine loamy soil. After rotary tillage, ammonia gas was not detected at all LPM treatments. This result suggests that rotary tillage can reduce the nasty smell of LPM quickly. Inorganic nitrogen, $NO_3$ and $NH_4$, contents in water of paddy was higher at coarse loamy soil from rice transplanting to tillering stage. After that season, inorganic nitrogen contents of water were not different according to soil texture and treatments. Content of $NH_4-N$ in soil solution was higher at LPM plots than chemical fertilizer plot. Total nitrogen contents in rice plant after harvesting were higher at chemical fertilization plot than LPM application plot, but K contents showed an opposite tendency. Rice yield was decreased only in LPM plots at two soil textures. But yield was not significantly difference between chemical fertilizer and LPM+top dressing plots at coarse loamy soil and increased 5% at LPM 50%+NK 50% plot at fine loamy soil in 2001.

• Korean Journal of Organic Agriculture
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• v.26 no.1
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• pp.99-128
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• 2018

The cultivation area of rice as staple grains is decreasing in the domestic situation in Korea. Import volume of a duty in foreign rice is 409,000 tons for a year regardless increasing of production per unit area and decreasing of rice consumption. The total stock of rice is increasing cumulatively despite the effort for production mediation of rice. Therefore, maintenance of cultivation area and reduction of production are necessary for national foodstuffs security problems. Development of environment-friendly and low-carbon technology as alternative of global warming and aging of farm labor power is very important responsibility for descendants with creation of sustainable agriculture environment. As alternative for demand and supply stabilization of rice from all angles, first stage: extension of environment-friendly cultivation area as 17% Jeollanam-do level with maintenance of cultivation area under the present circumstances, second stage: extension of environment-friendly cultivation area as 25%, third stage: extension of environment-friendly cultivation area as 35%. From above mentioned scenario, reduction of rice production (60,000 tons), increases of production cost (59,200,000,000 Won), and reduction of income (201,500,000,000 Won) are estimated in first stage. Reduction of rice production (90,000 tons), increases of production cost (122,100,000,000 Won), and reduction of income (313,700,000,000 Won) are estimated in second stage. Reduction of rice production (380,000 tons), increases of production cost (222,000,000,000 Won), and reduction of income (464,500,000,000 Won) are estimated in third stage. From analysis results for partial tillage in transplanting cultivation complex (10ha), rice production is decreased 1.3~1.5 ton by complex. Production cost of rice is decreased and increases of income cultivation type. Gradual extension of environment-friendly agriculture and low-carbon partial tillage could be expected for environment maintenance of the territorial integrity, confidence of consumer, and high-efficiency of low-cost.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.4
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• pp.227-233
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• 2013

'Taehan' (Avena sativa L.), a winter oat for forage use, was developed by the breeding team at the Department of Rice and Winter Cereal Crops, NICS, RDA in 2012. It was derived from a cross between 'Malgwiri' and 'CI8015'. Subsequent generations were handled in bulk and pedigree selection programs at Suwon and Yeoncheon, respectively. After 2 years of preliminary and advanced yield tests, 'SO00020B-YB-15-5-9-4-3', designated as 'Gwiri78', were subsequently evaluated for earliness and forage yield during 3 years in four regions such as Yesan, Iksan-1 (Paddy), Iksan-2 (upland), and Jeju from 2010 to 2012, and finally named 'Taehan'. Over 3 years, the heading date of 'Taehan' was about 6 days earlier than that of the check cultivar 'Samhan' (May 8 and May 14, respectively), and their average forage dry matter yield harvested at the milk-ripe stage was 14.5 tone $ha^{-1}$, compared with 14.1 tone $ha^{-1}$ for the check cultivar. The cultivar 'Taehan' was lower than that of the check cultivar 'Samhan' in terms of protein content (6.3% and 7.7%, respectively) and total digestible nutrients (60.7%, and 62.1%, respectively). The TDN yield was more than that of the check cultivar (9.1 tone $ha^{-1}$ and 8.0 tone $ha^{-1}$, respectively). Fall cropping of 'Taehan' is recommended only in areas where average daily minimum mean temperatures in January are > $-6^{\circ}C$, and it should not be cultivated in mountainous areas, where frost damage is likely to occur.