• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.371-378
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• 2009

This study was carried out to investigate the improvement effect of soil fertility by incorporation of GMC(green manure crops) at rice cropping after cultivation GMC such as the barley for alternative rye in paddy field over the past two years(2006~2007). Plots, which consisted of incorporation time of GMC as rye; heading stage, barley; heading stage, heading stage of rye and 10days after heading stage were divided by amount of applied rates; standard fertilizer fertilization, diagnosis fertilization and non-fertilization. we investigated change of soil physico-chemical properties, degree of decomposition on GMC in soil, growth and yield potential. The obtained results were summarized as follows. The fresh weight of GMC at incorporation time on heading stage of rye, heading stage and 10days after heading stage of barley were $2,715,\;2,352,\;2,867kg\;10a^{-1}$ respectively. Content of total nitrogen at three incorporation times was 1.31, 1.46, 1.38% and the C/N ratio were 33.4, 28.7, and 34.6, respectively. Some soil physical properties, such as soil hardness and bulk density tended to decrease with incorporation of GMC, while surface soil depth and porosity were increased. Some soil chemical properties, such as content of exchangeable cations and cation exchangeable capasity(CEC) were increased with incorporation of GMC compared with before experiment. Rice yields was increased 3~9% in diagnosis application plots on application of barley compared with control($559kg\;10a^{-1}$) and incorporation of barley caused to improve perfect kernel ratio 73.6~78.7% in appearance characteristics of brown rice compared with cotrol(73.0%). It was found that incorporation with 10days after heading stage of barley was more effective to reduce chemical nitrogen fertilizer and to improve soil fertility.

• Korean journal of applied entomology
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• v.15 no.3 s.28
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• pp.127-132
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• 1976

This experiment was conducted to several agricultural chemicals such as cuperic sulfate, lime sulfur, swep 80 wp, dithane A-40 and dichlone 50 wp for use as algaecide in wetted nursery of rice, and chemicals were applied at 5 day before and after sowing. The results are summarized as follows. 1. It was found that the effective chemicals as algaecide in wetted nursery were dichlone 50 wp and swop 80 wp, but chemical damage appeared to plant when dithane A-40 and swep 80 wp was applied. 2. Cuperic sulfate was identified to control algae, but it seems to be injurious to seed germination when applied in wetbed nursery. 3. Results were revealed that except dichlone, 50 cuperic sulfate, lime sulfate, swep 80 wp and dithance A-40 decreased the number of roots, rate of dry matter production and plant height compared when no chemical was applied. 4. Dichlone 50 wp was recognized as the most suitable algaecide in view of the plant growth and algae control in wetbed nursery.

• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.43-58
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• 2020

Mulching plastic is used for the purpose of maintaining soil temperature, moisture, and weed and pest prevention in agriculture. Any remaining plastic after use may contaminate the soil and damage crop growth. To solve this problem, mulching plastic wrappers have been studied and developed, but the actual use rate is quite low due to their poor performance and frequent tearing of the plastic on the field. In this study, we developed a tractor attachable mulching plastic wrapper to minimize the tearing of the mulched plastic. The developed mulching plastic wrapper consists of hydraulic motors and pumps, valves, a microcontroller, and sensors. The collecting speed of the plastic mulch was calculated considering the tractor's travel speed and the radius of the collecting drum. A proportional controller was designed to control the rotating speed of the hydraulic motor as the plastic was wound around the collection drum and the radius increased. The performance of an indoor experiment was quite promising because the difference between the collecting speed predicted by the calculation and the actual collecting speed was 2.71 rpm. Based on a field verification test, the speed difference was max. 14.28 rpm; thus, the, proportional integral derivative (PID) controller needs to be considered to control the drum speed precisely. Another issue was found when the soil covered at the edge of the plastic was hardened or the road surface was uneven, the speed control was unstable, and the plastic was torn. In future research, vibrational plows will be equipped to break-up the harden soil for collecting the plastic smoothly.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.5
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• pp.129-137
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• 2015

The objective of this study was to test the non-point source pollution (NPS) control by the vegetated ridge and silt fence through field monitoring. The experiment plots were established with three sizes which are 5 m width by 22 m length with 8 %, 3 % slope and 15m width by 15 m length with 6 % slope. Flumes with the floating type stage gages were installed at the outlet of each plot to monitor the runoff. For a rainfall monitoring, tipping bucket rain gage was installed within the experiment site. Water quality samples were monitored during the heavy rainfall occurred. The amount of rainfall from 4 monitored events ranged from 27.6 mm to 130 mm. The runoff reduction rate could vary depending on slope, soil, crop growth condition, rainfall amount, rainfall intensity, antecedent moisture condition, and many other factors. The runoff from vegetated ridge and silt fence treatment plots was 24.05 % and -8.28 % lower than that from control plot, respectively. The monitoring results showed that the average pollution loads reduced by vegetated ridge compared to control were BOD 36.62~53.60 %, SS 40.41~73.71 %, COD 39.34~56.41 %, DOC 49.08~53.67 %, TN 26.74~67.23 %, and TP 52.72~91.80 %; by silt fence compared to control were SS 41.73 %, COD 1.93 %, and TN 2.38 %. The paired t-test result indicated that the vegetated ridge and silt fence were statistically significant effect in SS load reduction, with a 5 % significant level. Monitored results indicated that vegetated ridge and silt fence were both effective to reduce the pollutant from the field surface runoff.

• Korean Journal of Environmental Agriculture
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• v.40 no.3
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• pp.161-168
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• 2021

BACKGROUND: Biochar has ability to reduce N loss, increase crop yield, and sequestrate carbon in the soil However, there is still limited study concerning the interactive effects of various biochars on NH₃ loss and plant growth. This study, therefore, was conducted to investigate the NH₄⁺ adsorption characteristics of biochar derived from rice and maize residues. METHODS AND RESULTS: By-products were pyrolyzed under oxygen-limited conditions at 300-700℃ for 1 hour and used for experiment of NH₄⁺ adsorption in aqueous solution. The adsorption characteristics of biochar were studied using Langmuir isotherm. Biochar yield and hydrogen content decreased with increasing pyrolysis temperatures, whereas pH, EC, and total carbon content increased. The biochar pyrolyzed at lower temperatures was more efficient at NH₄⁺ adsorption than those produced at higher temperatures. In addition, the R_L values, indicating equilibrium coefficient were between 0 and 1, confirming that the result was suitable for Langmuir isotherm. CONCLUSION: The maize stalk biochar pyrolyzed at 300℃ was the most efficient to adsorb NH₄⁺ from the aqueous solution. Furthermore, the adsorption results of this experiment were lower than those of other prior studies, which were ascribed to different experimental conditions such as ingredients, and pyrolysis conditions.

• Korean Journal of Weed Science
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• v.11 no.3
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• pp.211-218
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• 1991

The allelopathic potentials of several Korean weeds were inverstigated in the greenhouse and laboratory. Aqueouse extracts and plant litters of several weeds were tested at different dilutions for allelopathic effect on germination and Barley growth of crop species. Among the several species of weeds. Portulaca oleracea and Chenopodium album had the highest allelopathic effect to the four species to 30%, while the extract of Portulaca oleracea increased those to 4.7% on an average when compare with control plant. In greenhouse experiment Portulaca oleracea highly reduced the emergence rate indices of barley, soybean. radish and corn to 30, 49, 36 and 68% that of control plant, respectively. Plant height and dry weight of indicate plants were reduced by the residues of Portulaca oleracea and Chenopodium album.

• The Korean Journal of Mycology
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• v.28 no.1
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• pp.1-5
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• 2000

This experiment were carried out to investigate the effect of the rice bran added into spawn various amounts on the cultivation. Our results show that 10 to 20 percent addition of the rice bran as a supplement results in a good mycelial growth and density. However we didn't find a significant variance among the different species of oyster mushroom using poplar sawdust as a medium. When it inoculated spawn with various amounts of rice bran on the medium of rice straw, the mycelial density was increased according to the increase of the added supplement, while there was no significant in the mycelial growth among the treatments. Through the field test it was showed that 15 to 20 percent addition of the supplement results in the highest yield, the shortest days from spawing to pinhead, and the lowest infection rate.

• Magazine of the Korean Society of Agricultural Engineers
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• v.16 no.2
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• pp.3430-3437
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• 1974

.It is very importaut to know the water consumption of crops in planning irrigation works and practicing suitable soil moisture management. For the purpose of making it clear that how much water be consumed to cultivate the Chinese cabbage, Chamber method has been applied. Main equipments in the transpiration chamber are flowers, manometer and electric thermograph. The chamber made of vynyl plate has a small entrance at the base and an exit at the top, and the ventilation in the chamber was carried out by a flower through the entrance and exit. Air-flow adjusted by an orifice manometer enters the chamber from the outside over the crop canopy through the pipe like a chimney and finally goes out to the outside. Two sets which consist of a pair of dry and wet bulb made by thermistor are installed in the entrance and exit tube, and record air temperature automatically. Evapotranspiration amount is computed from the air-flow quantity and difference in absolute humidity between at the entrance and exit of the chamber by the following equation: ET=(X2-X1)${\times}$Q where ET=evapotranspiration amount X1=absolute humidity at the entrance(g/㎥) X2=absolute humidity at the exit(g/㎥) Q=air-flow quantity(㎥) This study was carried out at the upland farm of the Institute of Agriculture Engimeering and Utilization, Suwon, Korea. from 1971 to 1973. The results obtained in this experiment are as follows: 1. The total amount of evapotranspiration of Chinese Cabbage that is cultivated in autumn is 408.1mm during growth period. 2. Chinese cabbage rapidly grows up in the second ten days of September, 40th to 50th days after seeding. At the same time, the maximum amount of evaportranspiration of Chinese cabbage is 61.6mm/10 days 3. The correlation between Pan-evaporation and evapotranspiration is high, coefficient of correlation r=0.88**, and can be shown as The following regression equation: ET=0.913E+20.273 4. Evapotranspiration is closely related with meteorological factors: r=0.85**, for insolation, r=0.76** for air temperature, respectively. 5. The percentage of evapotranspiration amount, at the beginning of growth stage, gradually increases in proportion as the Chinese Cabbage grows but is largely affected by meteorological factors after the green cover formation. 6. By Blaney and Griddle formula, evaportranspiration coefficient "K" are within from 0,85 to 1.27.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.1
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• pp.65-70
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• 2005

This study was conducted to investigate the effect of combine crawler attaching slurry spreader on soil and growth of rye. The performance test at actual field was conducted to test for possibility of practical use. Field test of the slurry spreader was operated in upland and paddy field. Experiments was conducted to compare the effects of the soil damage and crop productivity incorporating Pig slurry by two different types of slurry spreader. In this experiment a slurry spreader using crawler of combine have been designed and developed to enhance the operation in small field and reduce e damage of soil structure. but it was not suitable for transference in long distance. Conventional tractor mounted vacuum is not suitable for $71.6\%$ water condition in the small areas of paddy land. But the slurry spreader using crawler could be controlled the working point and moving by crawler in paddy land of small area. The wheels depths of soil in the supplementary application in the rye field was 4.9 m in tractor mounted spreader. but the wheels depth of crawler attaching spreader was 1.6cm. The dry matter yield of rye was reduced by $12\%$ in supplementary application of slurry due to mechanical damage from passage of the tires. This is particularly noticeable at high soil moisture condition in paddy land. It was concluded that the slurry spreader developed in this study could be successfully used for basal and supplementary application of slurry in rye paddy field.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.4
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• pp.283-290
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• 1996

This experiment was carried out to determine the effects of soil condition that previous crop cultivated after [TO: Soil of corn cultivated, T1 : Soil of rye monoculture cultivated(l50kg/ha), T2 : Soil of mixedculture cultivated(Rye : Red clover = 120 : 3koa). T3 : Soil of mixed-culture cultivated(Rye : Red clover = 90 : 6kg/ ha), T4 : Soil of mixedculture cultivated(Rye : Red clover = 60 : 9kg/ha), T5 : Soil of mixedculture cultivated (Rye: Red clover = 30 : 12kg/ha), T6 : Soil of red clover monoculture cultivated(l5kgha)) on the growth characteristics and nutrient yield of silage corn. The results are summarized as follows. 1. The plant length of silage corn was high in order of T6>T5>T4 treatment. In the leaf length, T5 and T6 treatment showed short compared to the other treatments, but they were wider than the other treatments in leaf width. In the number of leaf, T6 treatment was the highest as 14 leaves per plant, while T1 treatment showed lower than the other treatments as 12.6 leaves per plant. 2. In the stem hardness, ear length, ear width and ear full degree, soil treatment of red clover mono-culture cultivation(T6) showed higher than the other treatment as 5.1 1kg/$cm^2$, 20.8~~1, 7.7cm and 97%. respectively (P<0.01, 0.05). Ihe leaf of summer depression did not many occurrence, but T6 treatment was lower than the other treatment as 0.8 leaf per plant. 3. ADF and NDF composition were not affected by soil condition. Crude protein composition of T6 treatment was the highest as 7.8%. while TI treatment was the lowest as 6.9%. Fresh weight yield(59,083kg/ha), dry matter yield(21,743kg/ha), crude protein yield(l,369kg/ha) and TDN yield(15,800kg/ha) at T6 treatment were much more increased by 41.9, 47.5, 57.4 and 49% than TI treatment(39,410, 14,259, 827 and 10,056kg/ha).