• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.12
• /
• pp.1674-1680
• /
• 2000

A study was conducted to compare the feeding value of urea treated and untreated mustard straw (MS) for sheep. Treated MS was prepared by adding urea-N at 1.84% and followed by packing in a pit silo for 21 days. Two groups of six empty Avikaline ewes were fed untreated (UTMS) and treated (TMS) mustard straw along with 200 g concentrate per head daily for 90 days. Untreated MS had 0.41% N and the urea treatment increased its N value to 1.58 %. The cell wall constituents were decreased in the TMS except for cellulose which remained unaffected. Dry matter intake of TMS was consistently higher than that of UTMS. Digestibility of DM, OM and fibre fractions of MS improved by the urea treatment. Ewes in both groups were in positive N balance while % N retention was lower in UTMS (26.30%) than in TMS (52.14%). The TMS fed group on average consumed 30.2 g DM, 2.9 g digestible crude protein and $0.2MJ\;DE\;per\;kg\;BW\;day^{-1}$ and maintained their weight whereas, the UTMS fed ewes lost weight. The VFA concentration in rumen liquor was higher in TMS than in UTMS. Total-N, ammonia-N and TCA-precipitable-N were also higher in TMS fed ewes. Blood glucose concentrations in the two groups were similar at initiation of the study. However the glucose concentration of UTMS fed group was significantly (p<0.01) lower than those fed UTMS at the termination of the study. Urea-N concentration was also higher in TMS fed group after 90 days of feeding period. It is concluded that urea treatment of MS improved N value of MS from 0.41% to 1.58% along with sizable improvement in nutritive value and in conjunction with 200 g concentrate, TMS can serve as maintenance ration for sheep. ($ME_{lakt}/ME_{m}=1.46$).

• Korean Journal of Soil Science and Fertilizer
• /
• v.41 no.4
• /
• pp.247-253
• /
• 2008

Winter annual green manure crops may be an effective tool for environmental-friendly agriculture system. The effect of legume (hairy vetch), non-legume (rye) and N fertilization ($190kg\;N\;ha^{-1}$) was examined and compared on red-pepper yield, nitrogen uptake, carbohydrate composition, and soil N and C contents. We monitored soil N and C for 120 days after incorporation (DAI) of green manures or mineral fertilizer. The mineralization of nitrogen reached the maximum around 30 DAI. The amount of inorganic nitrogen supplied by mineralization of hairy vetch residue was greater with than chemical N or rye. Photosynthetic rate was similar by 70 DAT in all treatments however, it in rye-incorporated red-pepper presented a sharp decline at later growth period. Leaf total nitrogen was greater with hairy vetch and chemical N than rye throughout the experiment. The soluble sugar increased steadily in all treatments from 40 to 110 days after transplanting (DAT) whereas starch showed a tendency of great decrease. Hairy vetch greatly promoted red-pepper growth by the later period however, chemical N showed the highest fruit yields.

• Korean Journal of Environmental Agriculture
• /
• v.3 no.2
• /
• pp.1-8
• /
• 1984

The present study was performed to elucidate pesticide residues in paddy rice applied with different application schedules and frequencies of pesticide formulations. Pungsanbyeo($Japonica{\times}Indica hybrid$) of rice(Oryza sativa L.) was chosen as target crop. Isoprothiolane(diisopropyl-l,3-dithiolan-2-ylidene malonate) 40EC (emulsifiable concentrates), 12G (granular), and chlorpyriphosmethyl [0,0-dimethyl 0-(3,5,6-trichloro-2-pyridyl) phosphorothioate] 25EC, 3G were selected as pesticide formulations. The closer the isoprothiolane EC application to harvest, the higher the residues in rice straw retained at harvest; however the G application on 30 days before harvest resulted in highest residue. Chlorpyriphosmethyl residues were higher as it was applied nearby to harvest. Degradation rate of chlorpyriphos-methyl in husked rice was quite similar to in rice straw, on the other hand isoprothiolane in the rice was more stable than that in rice straw. Translocated amount of applied G formulation to husked rice was meager irrespective to the chemicals. Percent reduction of isoprothiolane residues in husked rice by polishing was not related to application frequencies but to application date before harvest. Residual portions in rice straw, husked rice and polished rice of total input amount during rice cultivation were ranged from 0.19% to 0.99%, 0.01% to 0.48%, and 0.15%, respectively.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.23 no.1
• /
• pp.49-63
• /
• 1981

본 연구는 3개의 서로 다른 농지보전처리를 가진 시험구 및 테라스처리가 없는 목초용 Bromegrass 시험구에 있어서의 강우, 유출현상과 토양유실 관계를 규명함으로써 합리적인 농지보전 대책과 작부체계를 제시코저 하는데 그 목적이 있다. 강우, 유출 및 토양유실에 관한 분석고찰은 3개의 농지보전 시험구에서는 5년간(1972-1976년)의 자료를 그리고 Bromegrass 목초시험구에서는 3년간(1972-1974년)의 자료를 대상으로 하였다. 3개의 농지보전처리구는 첫째로 Non-terrace에 추경 춘조파형식의 관행법에 의한 비처리구와 둘째로 급역구배 테라스를 가진 초생수로에 가을 수확시 crop residue를 남겨두고 봄에 경작조파하는 Till plant system을 가진 초생수로구 그리고 마지막으로 지하배수와 함께 역구배 Terrace를 구비한 조파의 Till plant system 을 채용한 배수구를 나누어진다. Bromegrass 처리구는 Terrace나 기타 농지보전책이 없는 목초용 시험구이다. 이상의 연구에서 얻어진 결과를 요약하면 다음과 같다. 1. 시험기간대의 평균강수량은 네브라스카 링컨 지방의 76년간의 평균치, 728mm보다 66mm가 적은 662mm이였고 1974년과 1975년은 평균치보다. 300mm나 적은 극히 건조한 해 이였으며 1972년과 1976년은 거의 평균강수량에 가까웠고 1973년만은 평균치보다. 240mm나 더 많은 다우년 이었다. 2. 관행의 작부체계를 가진 비처리구에서의 연평균 유출고(2.44cm)는 역구배의 Terrace를 가지고 Till plant system을 채택한 초생수로구의 유출고(2.42cm)와 거의 유사하나 치였다. 3. 배수처리구로부터의 유출은 3개의 농지보전 처리구 중에서 5년간의 평균치가 1.57cm/year로 초생수로구와 비처리구의 유출보다 35%나 적은 가장 낮은 결과를 나타내었다. 4. Bromegrass 목초처리구에서의 유출은 방목정도에 따라서 영향되었다. 1972년의 무방축시 유출은 다른 3개 추리구로 부터의 유출으 7 내지 19%내인 0.07cm 정도였으나 1973년과 1974년의 방축년에는 조차 3개 처리구(3.4-5.18cm)에 필적되는 연평균 4.16cm로 나타났다. 5. 전체 시험구로부터으 연평균 토양유실량은 Sharpsburg 점질양토에 대한 S.C.S 한계허용치 10ton/ha/year 이내로 나타났다. 비처리구에서의 토양유실량은 평균 2.56ton/ha/year로 높게 나타난 반면 3개의 서로 다른 추리구인 비수구, 초생수로구 및 Bromegrass구에서는 각각 0.152, 0.192 및 0.290ton/ha/year로 낮은 결과를 가져왔다. 6. 평균 침전량에 대한 L.S.D. 검정 걸과 전시험구중 비처리구가 고도의 유의차를 나타낸 반면 비수구, 초생수로구 및 Bromegrass 목초구 간에는 아무런 유의차가 인정되지 않았다. 7. 농지보전 처리구인 배수구와 초생수로구는 비처리구에 비해 낮은 침두 유출량과 낮은 토양유실량을 나타내었다.

• Korean Journal of Environmental Agriculture
• /
• v.1 no.1
• /
• pp.14-21
• /
• 1982

Analytical methods for residues of six N-methylcarbamate insecticides were investigated to compare the minimum detectability, recovery from several crops and feasibility of multiple residue analysis. Those methods studied in this work included spectrophotometry by diazotization and gas chromatography by N-trifluoroacetylation(TFA), pentafluorobenzylether(PFB) and dinitrophenylether (DNP) derivatization. Maximum absorbed wavelength of the diazotized MIPC, XMC, BPMC, propoxur and carbofu ran was around 460 ㎚, while that of carbaryl recorded 510 ㎚. Recovery from brown rice and apple by diazotization method ranged from 80 to 120% and minimum detectable limits were 0.03 to 0.05 ppm in 50 g of the sample. Minimum detectability of PFB derivatives by gas chromatography was superior to TFA and DNP derivatives. DNP derivatives showed the longest retention time among the given derivatives. Recovery from crops by gas chromatographic met hod ranged 74 to 94%, 78 to 93%, and 85 to 99% in brown rice, rice straw and apple, respectively. Limit of detection was 0.01 ppm for TFA, 0.005 ppm for PFB and 0.02 ppm for DNP derivatives in 50 g of the crop samples.

• Korean Journal of Soil Science and Fertilizer
• /
• v.30 no.1
• /
• pp.16-22
• /
• 1997

Determination of N mineralization and nitrification potentials of selected Piedmont soils of North Carolina requires a better understanding of the influences of incorporated plant residues. The net N mineralization and nitrification were significantly influenced by the soil types and by plant species. The net N mineralization and nitrification of soils mixed with plant residues were consistently increased with successional incubation periods. The net mineralization and nitrification ranged from $9.77{\mu}g/g$ to $143.80{\mu}g/g$, and from $5.31{\mu}g/g$ to $145.66{\mu}g/g$ during the incubation periods, respectively. The net N mineralization was more influenced by NO3-N than by NH4-N. Overall, the greatest proportions of net N mineralization and nitrification occurred in Chewacla and Wehadkee and lowest in Enon and Mecklenburg. For the plant residues, the net N mineralization and nitrification were observed to be lowest in corn and highest in soybean. In a low-input agricultural systems, soybean may be planted as cover crop which may improve the nitrogen status of selected Piedmont soils of North Carolina.

• Korean Journal of Environmental Agriculture
• /
• v.38 no.2
• /
• pp.110-118
• /
• 2019

BACKGROUND: Residual organochlorine pesticides (OCPs) are designated as persistent organic pollutants (POPs) by Stockholm Convention because they bioaccumulate through the food web, and pose a risk of causing adverse effect to human health and the environment. Apple and pear is economic crop in agriculture, and its cultivation area and yield has been increased. Therefore, we tried to investigate the OCPs residue in apple and pear orchard soils and fruits. METHODS AND RESULTS: Extraction and clean-up method were developed using the modified QuEChERS method for residual organochlorine pesticides (ROCPs) in apple and pear orchard soil and fruits. Recovery and limit of quantitation (LOQ) of ROCPs in soil and fruits were 75.4-101.4 and 76.9-93.4%, 0.03-0.21 and $0.6-1.2{\mu}g/kg$, respectively. Detected ROCPs in apple and pear orchard soil was 2,4-DDT, 4,4-DDD, 4,4-DDE, 4,4-DDT, and endosulfan sulfate, the residues were 2.2, 1.9-48.0, 1.3-84.1, 90.6-863.1, and $11.3-239.0{\mu}g/kg$, respectively. But five pesticides in all fruit samples were not detected. CONCLUSION: These results showed that ROCPs residues in apple and pear orchard soil had no effect on safety of agricultural products.

• Journal of Food Hygiene and Safety
• /
• v.36 no.1
• /
• pp.9-16
• /
• 2021

The monitoring of residual pesticides in dried chili peppers and chili powders, which are circulated in Seoul from 2018 to 2019, was conducted for safety evaluation. As a result of analyzing for 71 kinds of pesticide residues in 101 cases of samples, pesticides were detected in 87 samples; however, no samples exceeded the MRLs (Maximum Residue Limits). Detection rates of pesticides in dried chili peppers and chili powders were 73.3% and 91.5%, respectively. The detection rate of residual pesticides in chili powders was a little higher than that in dried chili peppers. Twelve types of pesticides were detected, however, those pesticides were acceptable to use on peppers, according to the Crop Protection Guidelines. The most frequently detected pesticide was pyraclostrobin followed by flubendiamide, azoxystrobin, and chlorantraniliprole. The risk for detected pesticides was estimated as the ratio of ADI (Acceptable Daily Intake) to food intake rate. The ADI value resulting by intake of dried chili peppers and chili powders was in the range of 5.66E-05 to 3.34E-02, which was within a safe level.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.5
• /
• pp.842-847
• /
• 2012

This study was conducted to estimate the greenhouse gas emissions on local government levels from 1990 to 2010 using 2006 IPCC guideline methodology. To calculate greenhouse gas emissions based on the 16 local governments, emission factor and scaling factor were used with default value and activity data came from the food, agricultural, forestry and fisheries statistical yearbook of MIFAFF (Ministry for Food, Agriculture, Forestry, and Fisheries). The total emissions in crop sector gradually decreased from 1990 to 2010 due to a decline in agricultural land and nitrogen fertilizer usage. The annual average emission of greenhouse gas was the highest in Jeonnam (JN) with 1,698 Gg $CO_2$-eq and following Chungnam (CN), Gyungbuk (GB), Jeonbuk (JB) and Gyunggi (GG). The sum of top-six locals emission had occupied 83.4% of the total emission in cropland sector. The annual average emissions in 1990 by applying 2006 IPCC guideline were approximately 43% less than the national greenhouse gas inventory by 1996 IPCC guideline. Jeonnam (JN) province occupied also the highest results of greenhouse gas emission estimated by gas types (methane, nitrous oxide and carbon dioxide) and emission sources such as rice cultivation, agricultural soil, field burning of crop residue and urea fertilizer.

• The Korean Journal of Pesticide Science
• /
• v.15 no.3
• /
• pp.254-268
• /
• 2011

Fenoxycarb, pyriproxyfen and methoprene are juvenile hormone mimic insecticide. These insecticides have been widely used for mosquito, fly, scale insects, and Lepidoptera. The purpose of this study was to develop a simultaneous determination procedure of fenoxycarb, pyriproxyfen and methoprene residues in crops using HPLC-UVD/MS. These insecticide residues were extracted with acetone from representative samples of four raw products which comprised brown rice, apple, green pepper, and Chinese cabbage. The extract was diluted with saline water, and then n-hexane/dichloromethane partition was followed to recover these insecticides from the aqueous phase. Florisil column chromatography was additionally employed for final clean up of the extract. The analytes were quantitated by HPLC-UVD/MS, using a $C_{18}$ column. The crops were fortified with each insecticide at 3 levels per crop. Mean recovery ratios were ranged from 80.0 to 104.3% in four representative agricultural commodities. The coefficients of variation were less than 4.8%. Quantitative limit of fenoxycarb, pyriproxyfen, and methoprene was 0.04 mg/kg in crop samples. A HPLC-UVD/MS with selected-ion monitoring was also provided to confirm the suspected residues. The proposed simultaneous analysis method was reproducible and sensitive enough to determine the residues of fenoxycarb, pyriproxyfen and methoprene in the agricultural commodities.