• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.2
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• pp.91-99
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• 2017

The objective of this research was to investigate runoff characteristics of suspended solid (SS) and chemical oxygen demand (COD) from a paddy field watershed during storm events in the growing and non-growing seasons. Average of event mean concentration (EMC) of pollutants were 56.9 mg/L for SS and 23.9 mg/L for COD in the non-growing season and 50.3 mg/L for SS and 11.9 mg/L for COD in the growing season. The average EMC of SS in the study area was much lower than that in the uplands irrespective of cultivation, suggesting that paddy fields control soil erosion. This may be because flooding and wet soil in the growing season, and rice straw residue and stubble on the topsoil in the non-growing season reduce soil erosion. The changing tillage practice from fall tillage to spring tillage avoids soil erosion due to shortening of the tilled fallow period. However, the average EMC of COD in the non-growing season was about twice as much that in the growing season likely due to the runoff of organics like rice straw residues. The relationship between SS and COD loads and stormwater runoff volume was expressed by power function. The exponent for SS was higher than that for COD, suggesting that SS load increased with stormflow runoff more than COD load did. The mean SS and COD loads per storm during the non-growing season were much lower than those in the growing season, and therefore non-point source pollution in the growing season should be managed well.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.132-136
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• 2002

The rice straw managements are essential for maintaining soil fertility as well as reducing chemical fertilizer application in paddy field. A field experiment was conducted on moderately well draining alluvial paddy soil to investigate the decomposition pattern of rice straw. The mesh bags containing the rice straw harvested in the previous year were placed at soil surface and buried into around 10cm depth and recovered periodically for determining the straw decomposition. Pot experiments were conducted to investigate the fates of N released from $^{15}$ N-labeled rice straw under different levels of N fertilizer application. The overall decomposition patterns of rice straw were similar for the two incorporation depths in transplanted paddy field. The straw incorporated at transplanting date showed weight loss of about 50%, 70% and 90% after 2 months, 5 months, and 2 years, respectively. The decompositions of straw cell wall components showed somewhat different pattern. The decompositions of cellulose and silica were similar to that of dry weight while the decomposition of lignin was slower than that of cellulose and silica. N was released from rice straw 42% and 65 % of the initial N after one month and after five months, respectively. P release was faster than N release. Recoveries of rice straw-$^{15}$ N by rice plants were 10.2, 13.4 and 14.9% in 0, 120 and 240 mg N pot$^{-1}$ , respectively. Soil recoveries of rice straw $^{15}$ N were 17.3, 20.6 and 18.9% in 0, 120 and 240mg N pot$^{-1}$ , respectively.

• Korean Journal of Environmental Agriculture
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• v.40 no.2
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• pp.99-107
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• 2021

BACKGROUND: Pesticide uptake by a rotational crop after being used for the primary crop is a potential cause of violation against the pesticide law if the pesticide is not registered in the secondary crop. This study was conducted to investigate the plant back interval (PBI) of fluopyram for the rotational cultivation of radish. METHODS AND RESULTS: Two experimental approaches were performed the evaluation of residues in radish cultivated successively in soil 16 days after treated with fluopyram onto pepper plant (T1) and in radish cultivated in bare soil treated with fluopyram at PBI 30 and PBI 60 days (T2). A modified QuEChERS method coupled with LC/MS/MS analysis showed good linearity of matrix-matched standard calibration of fluopyram with the coefficient values of determination greater than 0.995. Recovery values at levels of 0.01, 0.05, 0.1 and 0.25 mg/kg ranged from average 84.9 to 117.6% with RSD less than 10%. Fluopyram residues in radish harvested from T1 and T2 were found as levels less than maximum residue limit. CONCLUSION: This study suggests 20~30 days as the PBI of fluopyram for the rotational cultivation of radish in the greenhouse soil treated with fluopyram used for pepper as the primary crop.

• Journal of Conservation Science
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• v.35 no.1
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• pp.19-31
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• 2019

To study the cleaning effects and post-treatment stability assessment of various methods of cleaning textiles with metal thread, six naturally-soiled historical textiles with metal thread were investigated at the Metropolitan Museum of Art, New York. Prior to the cleaning of fabricated gold, silver, and copper thread that had been glued onto a paper substrate, the artificial deterioration was carried out in a controlled environment with light(UV and daylight), and temperature and humidity factors which would weaken and damage the samples. A synthetic soil mixture was applied to the samples to imitate soil found on the historic and archaeological textiles with metal thread; the cleaning effect and post-treatment assessment were investigated by use of three textile cleaning methods: mechanical cleaning, wet cleaning, and solvent cleaning. While investigating the naturally-soiled textiles with metal thread, it was determined that the soil colors and sizes of contaminating particles of each textile were different due to the diversity of original environmental factors and conditions. After cleaning with kneaded rubber, Stoddard solvent, n-decane or n-hexane, a bright, clean effect was apparent. Kneaded rubber was successful in picking up both large and small particles, but its stickiness caused some of the metal leaf to peel off. Stoddard solvent produced a good cleaning effect, but after use of n-hexane and n-decane in the cleaning process, a white layer of residue remained on the textile's surface. Wet cleaning was not effective and the rapid humidity changes between wet and dry conditions caused the edges of the paper substrate to lose their original shape.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.401-406
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• 2020

The plant uptake of endosulfan, a new persistent organic pollutants from soil environment was investigated on ginseng through the field survey in Korea. The endosulfan residues in soil for this survey were ranged on 0.013-0.136 mg kg-1. The plant uptake factor (PUF) for endosulfan in ginseng was 0.243-1.708 and the highest PUF was found on 3-year-old ginseng. The PUF for endosulfan decreased in the longer cultivation period and it might be caused by the dilution effect of ginseng growth. In addition, the soil organic matter (SOM) content affected on the PUF negatively and Pearson correlation coefficient (r) between SOM and PUF was -0.7812 (p <0.05). Thus, higher SOM would positively affect to reduce the endosulfan residue in ginseng root.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.330-337
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• 2005

This study was investigated to elucidate the pesticide mobility in three different soil textures(Heongseong sandy loam; Chuncheon, loam; Taeback, silty clay loam) and four different gravel contents(0, 20, 40, 60%) of Taebaek soil using soil column. Carbofuran, which ranks the highest water solubility among 7 pesticides(carbendazim, carbofuran, chlorpyrifos, cypermethrin, dimethomorph, diniconazole and endosulfan) was defected over 87% in leachate samples within all soil types from early sampling time. Amount of 5 residual pesticides excluding carbendazim and carbofuran were ordered silty clay loam > loam > sandy loam, indicating pesticide residues are related to percentage of clay contents in soils. Comparing the amount of residual pesticides in soil column(upper, middle and lower layer), 6 pesticides apart from carbofuran were found in the range of $50{\sim}92%$ on the upper layer of silty clay loam and loam. Mobility of pesticides either in soil or leachate samples is dependant on water solubility of pesticide and clay content of soil. The results obtained from four different gravel contents of Tacback soil were similar to the results of three different soil textures. Also it was found that more the gravel contents, faster the flow velocity of leachate water. These results possibly provide an idea to select proper pesticides and to reduce soil and water contamination at alpine and sloped-land.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.667-673
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• 2011

There is relatively high vulnerability of soil erosion in slope highland agriculture due to a reclamation of mountain as well as low surface covering in early summer season with high rainfall intensity time. The aim of this study was to evaluate various surface covering methods for reducing soil loss in highland radish cultivation in highland. The experiment was conducted in 17% sloped lysimeter ($2.5m{\times}13.4m$) with 8 treatments including covering with cut rye, sod culture of rye, Ligularia fischeri var. spiciformis Nakai, Arachniodes aristata Tindale, Aster koraiensis Nakai, Festuca myuros L. and mulching with black polyethylene film, and runoff water, eroded soil and radish growth were investigated. Surface covering with sod culture and plant residue, especially cut rye treatment, had lower runoff water than non-covering, whereas black polyethylene film mulching had the reverse. The amount of eroded soil was also lowest in cut rye treatment, $0.3Mg\;ha^{-1}$, and increased in the order of rye sod culture, Ligularia fischeri var. spiciformis Nakai, Aster koraiensis Nakai, Festuca myuros L., Arachniodes aristata Tindale, black polyethylene film, and non-covering, $68.2Mg\;ha^{-1}$. The results showed that surface covering with sod culture or plant residue could be effective for reducing runoff water and soil erosion in the radish field, significantly in cut rye treatment. On the other hand, in sod culture of rye, Aster koraiensis Nakai and Ligularia fischeri var. spiciformis Nakai, radish yields were lower than in the non-covering. Unlike this, covering with cut rye, sod culture of Festuca myuros L. had similar radish yield to the non-covering radish yield. In conclusion, covering with cut rye and sod culture of Festuca myuros L. were beneficial for reduction of soil loss without decreasing in radish yield in highland sloped fields.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.344-344
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• 2017

The glycoprotein known as glomalin-related soil protein (GRSP) is abundantly produced on the hyphae and spores of arbuscular mycorrhizal fungi (AMF) in soil and roots. GRSP play a decisive role in the soil aggregation, but GRSP was also sensitive to agricultural managements. Thus, our objectives were to assess the effect of different cover crop incorporation on the GRSP content in soil and growth of subsequent soybean and maize. Pot experiments with the incorporation of four cover crops were set up. The same amount (666g) of aboveground plant parts of wheat (AMF host), hairy vetch (AMF host), mustard (non-host) and rapeseed (non-host) was separately incorporated into soils. The aboveground plant parts and roots of soybean and maize were grown in each incorporated pots and sampled at 6 and 9 weeks after sowing. Our results showed that the different cover crops incorporation affected soil biological and chemical properties such as EC, $NO_3-N$ content, ${\beta}-glucosidase$ activity, alkaline phosphatase (ALP) activity and GRSP content. The soil EC and $NO_3-N$ content in the hairy vetch, mustard and rapeseed was higher compared to the wheat. The ${\beta}-glucosidase$ activity in the wheat and hairy vetch was significantly higher than that in the mustard and rapeseed, and the ALP activity in the wheat was significantly higher than that in the hairy vetch, mustard, and rapeseed. The GRSP content in the mustard and rapeseed was significantly lower than that of the hairy vetch and wheat. Moreover, The top dry weight and leaf area of soybean and maize in the hairy vetch at 6 weeks were significantly higher compared to the other treatments. Our results indicated that the incorporation of mustard and rapeseed may cause indirectly the decrease of GRSP content and soil enzyme activity in soil. One possible explanation for the decrease of GRSP in non-AMF host crop treatments may be the decrease of AMF density in the soil. AMF are not able to form a symbiotic relationship with Brassicaceae roots due to the release of anti-fungal compounds. This means the AMF may not be able to produce GRSP in the soil. However, the differences in the benefit of cover crop incorporation were shown only by a pot experiment. Comparative investigations of crop residue managements would be applied to both pot experiment and field study to clarify a better selection of cover crops in rotation to encourage GRSP production.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.4
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• pp.269-274
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• 2014

Series of field experiments were conducted to evaluate the long term effect of gypsum and crop residue on crop yield and soil health in rice-wheat crop rotation system in salt affected soil. A saline-sodic field having $EC_e$ (electrical conductivity of the saturation extract) 4.77 ($dSm^{-1}$); pH ($H_2O$) 8.96; SAR 43.78 ($mmol\;L^{-1}$) and gypsum requirement (G.R.) 2.86 (Mg $acre^{-1}$) was selected on Soil Salinity Research Institute Farm. Five treatments consisting of ($T_1$) control, ($T_2$) gypsum at 100% G.R., ($T_3$) gypsum at 25% G.R. + wheat straw at $3Mg\;ha^{-1}$, ($T_4$) gypsum at 25% G.R. + rice straw at $3Mg\;ha^{-1}$, ($T_5$) gypsum at 25% G.R.+ rice and wheat straw at $3Mg\;ha^{-1}$ were replicated four times under completely randomized block design. The data indicated that grain and straw yield of rice and wheat was significantly (P<0.05) increased by all the amendments used either single or in combination. $T_2$ (gypsum at 100% G.R.) significantly (P<0.05) increased grain and straw yield of rice and wheat crops followed by $T_3$ (gypsum at 25% G.R. + wheat straw at $3Mg\;ha^{-1}$) when compared with control. Soil properties were also improved by used amendments, pronounced decreased in $EC_e$, $pH_s$ and SAR were recorded in $T_2$ followed by $T_3$. The efficiency of the treatments could be arranged in following order gypsum at 100% G.R.> gypsum at 25% G.R. + wheat straw at $3Mg\;ha^{-1}$ > gypsum at 25% G.R. + rice and wheat straw at $3Mg\;ha^{-1}$ > gypsum at 25% G.R. + rice straw at $3Mg\;ha^{-1}$ > control.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.96-106
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• 1998

Rice plants were grown for 42 days in the specially made micro-ecosystem(pot) containing two different soils treated with fresh and 60-day-aged residues of [$^{14}C$]quinclorac, respectively, to elucidate the behaviour of the herbicide quinclorac residues in the soils. Amounts of $^{14}CO_{2}$ evolved from two soils treated with different residues with and without vegetation were all less than 2.2% of the total $^{14}C$, indicating that there was little microbial degradation of quinclorac in soil. $^{14}C$-Radioactivity absorbed and translocated into rice plants from soil A and B containing fresh quinclorac residues was 8.4 and 24.2%, respectively, of the originally applied $^{14}C$, while 5.5 and 17.7%, in aged residue soils. These results indicate that larger amounts of $^{14}C$ were absorbed by rice plants from soil B with less organic matter and clay than soil A, and the uptake of [$^{14}C$]quinclorac and its degradation products decreased with aging in soil. After 42 days of rice growing, 84.5 and 61.8% of the $^{14}C$ applied freshly to soil A and B, respectively, remained in soil, whereas, in the case of aged soils, 86.3 and 67.7% of the $^{14}C$ applied did. Meanwhile, without vegetation, more than 98.3% of the $^{14}C$ applied, in both fresh and aged residues, remained in soil, suggesting that quinclorac was relatively persistent chemically and microbiologically. Most of the non-extractable soil-bound residues of [$^{14}C$]quinclorac were incorporated into the organic matter and largely distributed in the fulvic acid portion.