• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.341-349
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• 2005

Soil adsorption study was carried out to define the mobility of pesticides and to evaluate leaching potential in soils. Nine pesticides including metolcarb, molinate, fenobucarb, isazofos, diazinon, fenitrothion, dimepiperate, parathion and chlorpyrifos-methyl were subjected to adsorption experiment for four types of soils, such as upland, paddy, forest and volcanic ash soil. Based on Koc values, metolcarb and molinate were classified as mobile, fenobucarb as mobile or moderately mobile isazofos as moderately mobile, diazinon, fenitrothin, dimepiperate, and parathion as slightly or moderately mobile and chlorpyrifos-methyl as slightly mobile. Two evaluation methods, Groundwater Ubiquity Score (GUS) index and standard indices of soil-chemical adsorption and biodegradation (half-life), were used for the estimation of pesticide leaching potential. Leachabilities of metolcarb, molinate and fenobucarb were evaluated as high, and isazofos, dimepiperate and diazinon as a little potential, while fenitrothion, parthion and chlorpyrifos-methyl showed very low leaching potential. The leaching potential of pesticides was determined on the basis of intrinsic properties of the pesticides and the soil properties. Among the soil properties, organic matter gave a great influence on the leachability in soil. Therefore, leachabilities of the pesticides used were expected less in Sineom soil with relatively higher organic matter than Gangseo, Jungdong and Yesan soil with lower organic matter.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.1
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• pp.32-40
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• 2003

To characterize diel pattern of methane transport via rice plant, methane emission was measured on specific days in rice growing stages; tillering, meiotic, heading and harvest stages, from a paddy under different water management and organic amendments. Methane emission was monitored every two hours a day from chambers with and without rice plants. Proportion of the rice plant-mediated methane emission at different stage increased till the maximum growth of LAI and dry weight, and decreased thereafter. The proportion of methane emission through rice plants on June 18-19 at tillering stage was 38.4, 36.5 and 64.3 percent for NPK, Rice straw compost, RSC, and rice straw on February, RS2, respectively. The proportion on July 30-31 at meiotic stage was 70.4, 74.3 and 74.4 percent for NPK, RSC and RS2, respectively. The proportion on August 20-21 at heading stage was 80.1, 84.5 and 74.8 percent for NPK, RSC and RS2, respectively. The proportion on September 28-29 at harvest stage was 69.9, 65.9 and 64.4 percent for NPK, RSC and RS2, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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• pp.208-217
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• 2016

The Rural Development Administration moved to Jeonju for the balanced development of the land. This situation required establishment of new research fields with soils appropriate to cultivation. We applied a variety of amelioration techniques to mature soils of new research fields of the National Institute of Agricultural Science (NAS) and evaluated effects of the integrated amelioration techniques. The schedule of amelioration was following: 1) location of research fields was determined, 2) surface and subsoil samples were collected separately, 3) after aligning the top level of research fields, subsoil and surface soil were re-established with soil amendment, 4) the green manure crops were grown four seasons to improve the uniformity and increase the organic content of the research field, and 5) drainage canal and/or underdrainage were applied to poorly drained fields. The last green manure crop was rape in RDA fields and green barley in NAS fields. The average height, fresh weight, and dry matter weight of rape in good condition were 123 cm, $3,938kg\;10a^{-1}$, and $651kg\;10a^{-1}$, respectively. The height, fresh weight, and dry matter of green barley, on average, were 97 cm, $3,013kg\;10a^{-1}$, and $1,004kg\;10a^{-1}$, respectively. In the chemical properties of paddy field, pH and levels of silicate, calcium, magnesium, and potassium were in appropriate range but organic matter content of $16g\;kg^{-1}$ was less than the optimum level. In the chemical properties of upland field, pH and levels of phosphorus, calcium, magnesium, and potassium were appropriate range but organic matter content of $12g\;kg^{-1}$ was less than the optimum range. Evaluation of well-adapted soil was performed. The field in RDA was classified into the superior class with points ranging from 90 to 95 by the field evaluation test. The fields in NAS were mainly evaluated as the superior class with points greater than 85. However, some fields in NAS remained low quality with scores between 80 and 83. Further soil amelioration practices were suggested to fields with low soil quality.

• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.128-133
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• 2000

This study was conducted to investigate the adsorptive characteristics with cadmium in different levels of organic matter and lime in soil. And in order to identify the effect of soil ameliorators on cadmium uptake in rice plants, compost and lime were treated. Plants were grown at two soil textures(sandy loam and clay loam) with irrigation water containing $0.01\;mg\;L^{-1}$ of cadmium and treatments of two irrigation systems(intermittent irrigation and continuous submersion). The adsorption capacity of cadmium by soil was increased in proportion to initial concentration of solution, and it was higher at clay soil compared to loamy soil. The adsorption rate of cadmium by soil was increased with increasing the concentration of organic matter and lime in soil, highly increased at the both organic matter and lime treatment. Soil pH was negatively correlated with the cadmium contents of the both shoot and brown rice while Eh was positively correlated with those. In the harvest season, cadmium contents in the both leaves and brown rice were lower in the clay sail plots than sandy soil plots, and the continuous submersion plots were lower than intermittent irrigation plots. Cadmium uptake was highly reduced at the compost and lime mixture plot compared to other treatments among the continuous submersion plots. The cadmium content of shoot was positively correlated with that of brown rice in the harvest season.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.4
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• pp.351-357
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• 1987

A laboratory experiment was conducted to find out the effect of organic fertilizer as Bio-com$^{(R)}$ on the changes of pH and Eh values, gas evolution, ammonification and nitrification, and microbial population with farmer's compost and refused mushroom compost in submerged paddy condition. The results obtained are summarized as follows: 1. Application of compost and refused mushroom compost was increased the pH values than that of NPK alone. Organic fertilizer of Bio-com$^{(R)}$ showed the same results of the farmer's compost or refused mushroom compost. 2. Population of soil microbes as bacteria, actinomycetes and fungi was increased by application of compost, refused mushroom compost and Bio-com$^{(R)}$. Moreover, the results were pronounced more with the addition of NPK. 3. The application of Bio-com$^{(R)}$ was effected to the increase of the amount of $NO_3-N$ and the rate of nitrification than NPK, farmer's compost or refused mushroom compost. 4. The amounts of evolved gases as $CH_4$, $CO_2$, and $N_2O$ were not much differed with application of kinds of compost and NPK, but little increasing tendency was observed in application of NPK than that of NPK+kinds of compost.

• Korean Journal of Organic Agriculture
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• v.25 no.2
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• pp.373-386
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• 2017

The study was conducted to investigate seasonal nutrient dynamics in rice-cultivated soils collected from farmhouses of three large-scale environment-friendly agricultural districts (LEAD), Jangheung, Suncheon, and Okcheon in which environmental-friendly agriculture has been exemplarily practiced in Korea. Among three districts, Crop- livestock cycling organic farming system had been introduced only in Jangheung. pH and EC of farmhouse soils of three LEADs were ranged between 5.5 - 6.7 and $0.4-1.0dS\;m^{-1}$ from March to September, respectively. T-N was observed to be high on the farmhouse soil in Suncheon and K was observed to be lowest on farmhouse soil in Okcheon. Concentration of $NH_4-N$ in soil was observed to be highest on June, in particular on the farmhouse in Jangheung, but rapidly decreased due to the loss of fertilizer applied in Spring. Yield and harvest index were the highest on the farmhouse in Okcheon in which total annual gross production $ha^{-1}$ was nearly three time higher than those of other two farmhouses. Farmhouse soil of Okcheon was maintained the highest seasonal nutrient balance due to the high input of fertilizer. It was estimated that K balance in the farmhouse soil in Suncheon dropped to $-60kg\;ha^{-1}$ on September, and it might have some effect on the less rice productivity due to K deficiency. Farmhouse soil in Jangheung was maintained low seasonal balance of T-N and P but showed the highest N use efficiency in the rice grain. Based on above-mentioned results, we think Jangheung farmhouse can be recommended as a model farmhouse of LEADs.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1157-1163
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• 2012

This study was performed a comparative life cycle assessment (LCA) among three rice production systems in order to analyze the difference of greenhouse gases (GHGs) emissions and environment impacts. Its life cycle inventory (LCI) database (DB) was established using data obtained from interview with conventional, without agricultural chemical and organic farming at Gunsan and Iksan, Jeonbuk province in 2011. According to the result of LCI analysis, $CO_2$ was mostly emitted from fertilizer production process and rice cropping phase. $CH_4$ and $N_2O$ were almost emitted from rice cultivation phase. The value of carbon footprint to produce 1 kg rice (unhulled) on conventional rice production system was 1.01E+00 kg $CO_2$-eq. $kg^{-1}$ and it was the highest value among three rice production systems. The value of carbon footprints on without agricultural chemical and organic rice production systems were 5.37E-01 $CO_2$-eq. $kg^{-1}$ and 6.58E-01 $CO_2$-eq. $kg^{-1}$, respectively. Without agricultural chemical rice production system whose input amount was the smallest had the lowest value of carbon footprint. Although the yield of rice from organic farming was the lowest, its value of carbon footprint less than that of conventional farming. Because there is no compound fertilizer inputs in organic farming. Compound fertilizer production and methane emission during rice cultivation were the main factor to GHGs emission in conventional and without agricultural chemical rice production systems. In organic rice production system, the main factors to GHGs emission were using fossil fuel on machine operation and methane emission from rice paddy field.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.77-101
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• 2009

Organic farming in Korea has mainly focused on producing vegetables in plastic film house and cereals in paddy field. For high productivity of vegetables and cereals, most Korean farmers have not applied crop rotation in the cropping system. Thus, this study was carried out to evaluate the effects of crop rotation on the yield of red pepper and green onion, the changes in soil fertility and the potential as green manure of rye and hairy vetch. Rye and hairy vetch were cultivated for winter season every year, and directly incorporated into the soil. The yield of red pepper fruits in organic farming using crop rotation (OFCR) decreased 23 to 36% compared with conventional farming system (CFS). Whereas, green onion showed the increased yield of about 13%. In OFCR, total carbon content of soil was higher, however available phosphate content lower than conventional farming. As a result of measuring the bulk density of soil, OFCR and CFS were 1.26 to $1.35Mg/m^3$ and 1.37 to $1.42Mg/m^3$, respectively. Carbon and nitrogen contents of microbial biomass in OFCR were obviously higher compared with the CFS. In the plot cultivated rye for winter season, the weed germination was strongly reduced (about 52 %). Balance of macro nutrient elements, nitrogen and phosphate, in the application of rye and hairy vetch had a minus value. For potassium, the output value was higher than the input one, therefore organic farming under red pepper-rye or hairy vetch systems requires applying additional potassium input. Also, we selected two hairy vetch varieties of cv. Hungvillosa and Ostsaat which can be adapt at Korea climate. In order to estimate a yield of green manures, the weight of shoot and root was measured. The ratio of shoot and root between rye and hairy vetch showed 0.88 and 1.91, respectively. The potential levels of nitrogen, phosphate and potassium which could be supplied from rye were 7.7, 7.8 and 21.9 kg/10a and from hairy vetch were 17.0, 8.6 and 22.9 kg/10a, respectively. So we recommend that cultivating hairy vetch, as a nutrient supplier, and rye, as an amendment to enhance the soil physical property, for winter season be practical method in Korea organic farming system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.176-184
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• 2019

The rice variety Chucheongbyeo is mostly cultivated for organic farming in the central region of Korea. This variety is more delicate than the recently developed varieties in rice yield, quality, and pest resistance, and is therefore, not suitable for organic farming. This study was conducted to select suitable varieties for organic rice farming in the central plain area of Korea. We tested 15 different varieties in the organic paddy field of Cheongju city from 2011 to 2013. As the experimental field had good fertility because it had been organically managed for many years, culm length and number of panicles developed better than the varietal characteristics. Daebo, Chinnong and Hyeonpum had slightly lower ripened grain ratio than Chucheongbyeo. The milled rice yield of Samkwang, Sukwang, Haiami, Cheonghaejinmi and Daebo increased by 9-18% compared to that of Chucheongbyeo. The protein content was under 7% for Cheongnam, Sukwang, Daebo, Samkwang, Hyeonpum, Chinnong, Chilbo, Hopyung, Hwangkeumnuri, Suryeojinmi and Jinsumi and under 6% for Sukwang and Samkwang. The whiteness was over 40 in Sukwang, Daebo, Samkwang and Jinsumi. The palatability grade and head rice ratio were good in Daebo, Sukwang, Samkwang and Jinsumi. Therefore, this study recommended Samkwang, Daebo, and Jinsumi as the optimal varieties for organic rice farming in the central plain area of Korea. These varieties could replace Chucheongbyeo, which is inferior to the recently developed varieties in terms of disease and pest resistance and yielding performance.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.93-101
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• 2010

For the study of possibility of practical use as an organic farm materials of the mixtures with lignite and amino acid solution, this experiment was carried out to investigate the effects of the mixtures on the growth and the yield of rice plant, chinese cabbage, and red pepper, and the effects of the mixtures on chemical properties of soil. Also, when the mixtures of the lignite plus amino acid solution and the chemical fertilizer were applied to these three crop cultivation area, authors want to know how can the loss in quantity of chemical fertilizer affects the growth and the yield of these crops. As the results, growth of rice plant applied with the mixtures of lignite and amino acid solution was better than that applied with the recommended rate of chemical fertilizer. Especially, the growth of rice plant appeared to be good at the treatment of 150 kg/ha of the mixed lignite with amino acid solution and at that of its mixtures and standard fertilization. Growth of chinese cabbage and red pepper was good at the application of 600 kg/ha of the mixed lignite with amino acid solution and at that of its mixtures and standard fertilization. Yield of rice and chinese cabbage was good at the treatment of 150 kg/ha of the mixed lignite with amino acid solution and at that of its mixtures and standard fertilization, and yield of red pepper was good at the application of 600 kg/ha of the mixed lignite with amino acid solution and at that of its mixtures and standard fertilization. The organic matter content increased and while the exchangeable cation decreased when the lignite mixed with amino acid solution and the loss in quantity of chemical fertilizer applied at paddy field. Incase of these treatments, pH and available phosphorus increase at upland field, but did not change at paddy field.