• Korean Journal of Weed Science
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• v.18 no.4
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• pp.281-285
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• 1998

This experiment was carried out to evaluate the effect of recycled paper mulch on weed occurrence and the growth and yield of rice in dry-seeded paddy field. Mulch papers with basis weight of 105, 110, 115g/$m^2$ were fabricated from recycled corrugate container. It took about 80 days after mulching for the mulch papers to reach 50% decomposition, showing no significant differences among types of mulch paper. Paper mulching was very effective in controlling the paddy weeds at early stage of rice growth, but the efficacy of weeds control decreased a little at late season. However the efficacy was still higher than the plot using herbicide. The paper mulch plot showed rice yield similar to the weed control plot using herbicide. It could be concluded that paper mulch can be used as an alternative for non-herbicidal weed control and ensure as high yield as the conventional weed control method using herbicide in dry-seeded rice field.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.221-225
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• 2002

This study was conducted to identify the effects of slow release fertilizer (LCU) on ridge direct seeding on dry paddy of rice as an irrigation water-saying cultural system. During 1999-2000, a series of experiments was carried out at field (Chonbuk series) of the National Honam Agricultural Experiment Station, RDA using Dongjinbyeo. Plant height and culm length during the total growth duration were the longest and panicle umber per $m^2$ was the highest in 100% LCU application rate. Leaf area index and top dry weight were the highest in the 100% LCU application rate. They increased as more LCU was applied. Nitrogen uptake was the highest in 100% LCU application, and N use efficiency was the highest in LCU 60% + FP (fertilization at panicle formation stage) 20% application. Milled rice yield was 7% higher in 100% LCU application rate than that of conventional N application. Ripened grain rate and 1,000-grain weight of brown rice did not differ, but panicle number per $m^2$ and grain number per m2 were the highest at 100% LCU application.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.5
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• pp.1-9
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• 2014

The DIROM (Daily Irrigation Reservoir Operation Model) was modified to estimate amounts of water release from reservoirs, considering customary irrigation water management practices, such as water supply for puddling and transplanting paddy rice from seeding beds and mid-season drainage. The applicability of the modified model was investigated by simulating amounts of water release from three study reservoirs: Hwamae, Ogi, and Doya Reservoirs. In terms of annual amounts of water release, the relative errors between the observed and simulated values in 2012 and 2013 ranged -26.20 % to 10.28 % and 4.90 % to 30.06 %, respectively; in case of reservoir water levels, the RMSE values ranged 0.45 m to 1.34 m and 0.40 m to 1.27 m, respectively. Also, it was revealed that the model provided better simulation results for monthly water releases than the original model. In addition, the model presented better performance in simulating 10-day amounts of water release from April to June. However, the model had still significant errors in the simulation results from July to September because the reservoirs were practically operated to adapt to water management circumstances. Finally, it is concluded that the modified DIROM can estimate the amounts of water release from reservoirs, reflecting irrigation water management customs in paddy-field districts. To achieve higher prediction accuracy of the model, it is necessary to incorporate practical reservoir operation rules into the model.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.29-29
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• 2021

최근 물 사용에 대한 각 부문 간의 경쟁이 심화되고 있으며, 미래 기후변화에 대응하기 위해 체계적이고 효율적인 수자원 활용이 요구되고 있다. 농업용수는 우리나라 수자원의 40% 이상을 차지하고 있지만, 생활용수, 공업용수와 달리 경험에 기반한 관행적 관리가 이루어지고 있어 체계적인 관리가 필요하다. 농업용수의 체계적 관리와 분석을 위해 최신화된 수혜면적 파악 및 수혜구역 내 수로 네트워크 구축은 필수적 요소이다. 현재 활용하고 있는 농업용 저수지 수혜면적 및 수로 자료는 한국농어촌공사의 RIMS 자료를 기반으로 하고 있다. 하지만 기존 자료의 경우 준공 당시 설계기준으로 작성되거나 수년 전 갱신된 자료로 최신현황을 반영하지 못하고 있다. 이러한 문제점을 보완하기 위해 직접 측량을 통한 자료 취득 또는 농림축산식품부의 스마트팜맵과 같은 대체, 보완자료가 활용되고 있다. 직접 측량의 경우 최신화된 정확한 자료 취득이 가능하지만, 많은 시간이 소요되며, 스마트팜맵의 경우 취득 주기가 1~2년으로 주기에 따라 최신자료의 활용이 어려울 수 있다. 본 연구에서는 자료 산정 시간 단축 및 최신자료 취득을 위해 고해상도 영상을 활용하고자 하였으며, 여주시 삼합저수지를 대상으로 검증하였다. 영상자료로는 위성영상, 항공영상, 드론영상을 활용하였으며, 위성영상의 경우 구글어스 프로의 2020년 11월 고해상도 영상, 국토리지정보원의 2019~2020년 51cm급 항공 영상, 2020년 10월 촬영한 4cm급 드론영상을 사용하였다. 수혜면적 산정은 기존 RIMS 자료와 스마트팜맵을 통해 확인한 수혜면적에서 영상을 통해 확인한 토지이용 변경지역을 추출하여 재산정하였으며, 수로 네트워크의 경우 RIMS 자료를 기반으로 드론영상을 통해 확인된 수로 추가 및 DEM (Digital Elevation Model) 영상을 활용한 용수 흐름도 작성을 통해 구축하였다. 본 연구에서 재산정한 수혜면적과 수로 네트워크는 정확한 용수 수요량 및 공급량 산정, 관개 효율 분석 등과 같은 농업용수 분석 전반에 기초자료로 활용 가능할 것으로 판단된다.

• The Korean Journal of Pesticide Science
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• v.18 no.2
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• pp.88-94
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• 2014

Among pre-harvest environmental factors, increasing attention has been paid to the effects of chemical and microbiological factors on fresh produce. The occurrence and prevalence of these factors have been usually studied with regard to the final products at the post-harvesting stage and/or when they are sold in the market. However, the origin and routes of transmission of both factors remain to be clarified. In the present study, we examined the contamination levels of food-borne pathogens and chemical factors such as pesticide residues and heavy metals in 83 and 43 samples, respectively, including various soil, water, and fertilizer samples, as well as post-harvested and processed samples. Among the organic farming samples, only one pesticide, dimethomorph, was detected in the soil sample, however no pesticides were observed from any other samples in organic farming system. Thus, it was thought that might be contaminated from conventional farm land in the vicinity. Whereas many pesticide residues were detected in conventional farming systems such as soil, fertilizer, water, and fresh produce as expected. Furthermore, heavy metals detected from all tested samples did not shown contamination levels higher than the standard limit. We comparatively assessed the levels of contamination by food-borne pathogens on the samples from organic and conventional farming systems, and found aerobic bacteria at approximately 7 log CFU/g, with no significant differences observed between the two systems. Coliforms were present at lower levels than aerobic bacteria. No human pathogens were present among the coliforms detected, indicating that these bacteria are saprophytes without the ability to cause food-borne illnesses. In contrast, among the high-risk food-borne pathogens, only sporadic cells of Bacillus cereus were found on samples of organic farming system. These data extend previous findings that the most prevalent food-borne pathogen is B. cereus and demonstrate that it spreads to whole living plants via soil.

• Korean Journal of Environmental Agriculture
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• v.22 no.4
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• pp.246-250
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• 2003

In order to preserve the soundness of agro-ecosystem and products safety in agriculture, this study was evaluated environmental impact in relation to the INM (Integrated Nutrient Management) and IPM (Integrated Pest Management) at paddy fields at Ok-Chun and Yang-Pyung region. By introduction of INM with the application of BB(bulk-blanded) fertilizer based on soil analysis and IPM, the application rate of fertilizer was reduced to about $28.6{\sim}39.4%$ and the yield of brown rice was increased to about $3{\sim}10%$ compared to conventional practices. The concentrations of COD, $NH_4-N$, and $NO_3-N$ in irrigation water flowed to the environmental-friendly agriculture practices were 15.0, 0.67, and 1.39 mg/L, respectively. The concentrations of COD, $NH_4-N$, and $NO_3-N$ from paddy fields in drainage water were 12.4, 0.29, and 2.42 mg/L, respectively. The total number of the freshwater invertebrates was higher in field treated with fertilization by prescription with soil testing. Also, the population density of aquatic insects was higher than the other fields at both demonstration villages. In conclusion, it was possible to reduce the amount of fertilizer and agricultural chemicals application, and increase the yield of rice by application of the environmental-friendly agriculture practices.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.3
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• pp.154-162
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• 2003

This study was conducted to investigate the effects of tile drain on Physicochemical properties and crop productivity of soils under plastic film house for three years (1999 - 2001). Tiles (${\Phi}100mm$ PVC pipe) were established at 50-60 cm depth with 1 m, 2 m, and 3 m intervals in Gangseo silt loam soil under 2W-type plastic film house. Cropping system was a pumpkin-pumpkin in the first year, a cucumber-spinach-crown daisy-spinach-young radish in the second year, and a green red pepper-tomato-spinach in last year, with conventional fertilization and drip or furrow irrigation by groundwater pumping. Bulk density and soil hardness of plot with tile drain were lower than those of control (plot without tile drain). Soil water content was also lower in tile drain plot than in control regardless of soil depth, and decreased at narrower interval and longer distance from tile in the same plot, thus suggesting that water flow and density of tile drain plot was higher than those of control. Rhizosphere of spinach, a final crop of third year, was expanded more than 2 cm due probably to improvement of soil physical properties caused by tiles establishment. Electrical conductivity (EC) of topsoil decreased from $1.22dS\;m^{-1}$ to $0.82dS\;m^{-1}$ by tile drain system, and the extent of EC decrease was different with season: higher in spring and lower in summer and autumn. The $NO_{3^-}-N$ concentration in topsoil decreased, from $200mg\;kg^{-1}$ to $39mg\;kg^{-1}$. The effect of tile drain on crop yield varied with crops. Average crop productivity obtained in tile drain plot than that of control crop: 18.2% in 2 m interval, 14.2% in 3 m interval, but lower 0.2% in 1 m interval.

• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.35-44
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• 2009

This study was carried out to examine the growth performance of 4 species of cool-season grasses and 4 species of zoysiagrasses under salt injury in Seo-san reclaimed area. Grasses were grown on the plots with capillary water interruption layer (WCWIL) and without capillary water interruption layer (WOCWIL) soil systems. Cool-season grass and seeding-type zoysiagrass plots were seeded on 6 Jun, 2006. Vegetative zoysiagrass 'Junggi' was established by sprigging and 'Senock' and 'Millock' were plugged. Electric conductivities of irrigation water (ECw) ranged from 0.28 to $3.3\;dS{\cdot}m^{-1}$. Electric conductivities (ECe) of the soil with capillary water interruption layer and without capillary water interruption layer ranged from 0.55 to $9.4\;dS{\cdot}m^{-1}$ and from 1.84 to $9.4\;dS{\cdot}m^{-1}$ respectively. Leaf color, turf quality, coverage rates, and growth rates were rated visually for 2 years. Zoysiagrass 'Junggi', creeping bentgrass, zoysiagrass 'Senock' and 'Millock' showed acceptable growth at salty fairway condition, while Kentucky bluegrass, perennial ryegrass, Kentucky bluegrass mixed with perennial ryegrass, and seeded zoysiagrass 'Zenith' showed establishment rates below 70%. These results will be useful when choosing turf grass species and cultivars for the golf courses in reclaimed land area.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.123-129
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• 1987

In order to find out more effective countermeasures against growth damage of paddy rice due to the irrigation of livestock waste water, pot experiments were carried out in 1985 and 1986. Experiment I conducted in 1985 was to find out the effects of irrigation control and application of ameliorators to paddy soil with irrigation of animal waste water. Experiment II conducted in 1986 was to find out the amounts of wollastonite to be applied. The results obtained were as follows. Experiment I ; Rice yields were higher in the treatment of continuously submersion until harvest than in that of intermittent irrigation. The yield was also increased with the application of soil ameliorators and it showed higher increase in the treatment of zeolite and wollastonite. Nitrogen contents in plant were increased with the nitrogen application and more amounts of irrigation of waste water, but they were considerably decreased with the application of soil ameliorators. Experiment II ; Rice yields were increased with the application of wollastonite and the optimum level of wollastonite for maximum yield in condition of 3.0 g/pot of nitrogen application was belived to be 60g/pot. The increment of yield by the application of wollastinte was though to be due to increase of No. of grains per panicle and ripening ratio. Steriled neck occurred by rice disease such as rice blast was increased with increasing the amounts of nitrogen application and nitrogen contained in irrigated waste water but that was remarkably decreased with the application of wollastonite.

• Applied Biological Chemistry
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• v.15 no.1
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• pp.77-84
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• 1972

A field experiment was conducted to determine the factors responsible in limiting nutrient up take and root activity in low productive paddy fold. Radiosotope of phosphorus-32 was used as a tracer. Results of the study were as follows: 1. On yield components responsible for increase yield indicated that number of ears per panicle and ripening ratio were closely related to increase yield. 2. Root volume or root feeding area has significant influence in increasing rice yield. 3. Root volume indicative of root activity and nutrient uptake can be effected by reasonable water control. 4. The combined application of calcium, silica, and magnesium(as a fused magnesium phosphate. the Kyun-gi Chemical Co. products.) with water control, although under conditions of large amount application of nitrogen, was found to be increased the maturing rate. 5. In the plots of water control, the number of roots per one volume were less than that of the continuous flooding plots, but the weight per root was heavier than the flooding plot ones. 6. Improvement of the present native culture method could effectively increase paddy rice yield.