• Current Research on Agriculture and Life Sciences
• /
• v.11
• /
• pp.71-79
• /
• 1993

This study was conducted to obtain the basic information for the classification of Perilla spp. based on their major morphological characteristics for the 20 local collections of perilla distributed in Korea. The results of this experiment were summarized as follows : Several morphological characteristics were investigated. Seed color was classified to four groups with greshywhite, greshybrown, brown and darkbrown. The 1,000 grain weight, 11 accessions were below 3.5g, four accessions was 3.6g to 4.5g and five accessions was 4.5g to 5.07g. There was two types of stem color, red and green, 15 accessions was green and 5 accessions including Andongjaerae, Yeupsil, Ockdong, Cheongsongjaerae and Chugjaso were red color. In fatty acid composition was 60% in average. Among 20 accessions, Euseongjaerae showed the highest content(65%) and Yeongyangjaerae the lowest(54%) linolenic acid content. In the cytogenetical studies on the four accessions including Andong, Yeupsil, Yeongkwang and Daeyeong, the number of chromosomes were 2n=38.

• Korean Journal of Environment and Ecology
• /
• v.22 no.6
• /
• pp.625-631
• /
• 2008

We used the visitation aspect of dabbling ducks(Anas spp.) to investigate the estuarine ecosystem of Nakdong River and to compare the data collected during two periods: trom May, 1989 to April 1993 and from May, 2002 to April 2006. Over for the 8 years of field surveys, 356,110 individuals from 11 species of dabbling ducks(Anas spp.) were observed in the Nakdong estuary. In the early 1990s, the average number of species gradually increased from October through November, whereas the highest numbers of species were recorded in October during the second survey period. The average number of individuals recorded during the second period was 2-3 times higher than that observed in the 1990s. Statistical analysis using a t-test indicated that the number of individuals showed significant difference at 5% level between November and February in both the early 1990s and the mid-2000s. During the winter, dabbling ducks select both estuarine wetlands as resting sites and rice paddy as feeding sites. More wintering migrants including ducks would visit to Nakdong river if we provide with enough rice paddy near the estuary. The farmland around Nakdong estuary is used by dabbling ducks as a habitat, we hope it must be conserved thoroughly. CRP(crop reserve program), implemented by the local government of Kangseo-gu, Busan City is effective in conserving rice paddy; therefore, the CRP program need to be continuously applied in the Nakdong river basin.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.6
• /
• pp.949-956
• /
• 2020

Objective: This study was conducted to confirm the effects of new inoculants producing-antifungal or esterase substances on rye silage and its rumen fermentation indices by comparing wild with mutated types. Methods: Rye harvested at dough stage was ensiled into 3 L mini bucket silo (1 kg) for 90 d in triplicate following: distilled water at 20 μL/g (CON); Lactobacillus brevis 100D8 (AT) and its inactivation of antifungal genes (AT-m) at 1.2×10⁵ cfu/g, respectively; and Leuconostoc holzapfelii 5H4 (FD) and its inactivation of esterase genes (FD-est) at 1.0×10⁵ cfu/g, respectively. After silo opened, silage was sub-sampled for the analysis of ensiling quality and its rumen fermentation indices. Results: Among the wild type inoculants (CON vs AT vs FD), FD inoculant had higher (p<0.05) in vitro digestibilities of dry matter and neutral detergent fiber, the total degradable fraction, and total volatile fatty acid in rumen, while AT inoculant had higher (p<0.05) lactate, acetate, and lactic acid bacteria in silage. Silage pH and the potentially degradable fraction in rumen increased (p<0.05) by inactivation of antifungal activity (AT vs AT-m), but lactate, acetate, and lactic acid bacteria of silage decreased (p<0.05). In silage, acetate increased (p<0.05) by inactivation of esterase activity (FD vs FD-est) with decreases (p<0.05) of pH, ammonia-N, lactate, and yeast. Moreover, inactivation of esterase activity clearly decreased (p<0.05) in vitro digestibilities of dry matter and neutral detergent fiber, the total degradable fraction, and total volatile fatty acid in the rumen. Conclusion: This study concluded that FD inoculant confirmed esterase activity on rye silage harvested at dough stage, while AT inoculant could not be confirmed with antifungal activity due to the absence of mold in all silages.

• Korean Journal of Soil Science and Fertilizer
• /
• v.17 no.1
• /
• pp.1-6
• /
• 1984

Soils in Cheju Island, derived mostly from volcanic ashes, were collected for chemical analysis to determine the effect of land utilization pattern on soil chemical characteristics. The coastal area has long been used for intensive farming and some of the mid-mountain region were recently reclaimed for agricultural crop production. The cation exchange capacity and the organic matter in the soils increased in the order of coastal area < mid-mountain belt < upper mountain area, while pH, base saturation, available phosphorus and exchangeable bases decreased with the elevation. Generally, the organic matter, the cation exchange capacity and the exchangeable bases of the Cheju soils were found to be considerably higher than the Korean mainland soils. However, the base saturation and the available phosphorus were far below the mainland average. The ratio of monovalent basic cations to total exchangeable bases showed the highest in the soils of the mountain belts and the lowest in the coastal area soils. These data suggest that a higher soil pH in the coastal area as compared to the mountainous slopes has resulted not from the sea water but from continuous application of alkaline fertilizers and times.

• Korean Journal of Environmental Agriculture
• /
• v.35 no.3
• /
• pp.166-174
• /
• 2016

BACKGROUND: The current study developed a monitoring method of 6 veterinary antibiotics (amoxicillin, ampicillin, enrofloxacin, tetracycline, chlortetracycline, oxytetracycline) in agricultural soils using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive electrospray ionization mode.METHODS AND RESULTS: Sample preparation was carried out using acidic acetonitrile and citrate salts followed by purification with dispersive solid phase extraction (d-SPE). Separation on Eclipse Plus C₁₈ column was conducted in gradient of the mobile phase, 0.1% formic acid and 5 mM ammonium formate in methanol (A) and 0.1% formic acid and 5 mM ammonium formate in distilled water (B). The linearity of the matrix-matched calibrations expressed as the coefficient of determination was good with R²≥0.9900. The limit of quantifications (LOQs) ranged from 0.5 to 10 μg/kg for all analytes. Analysis of 51 agricultural soil samples taken in the Republic of Korea revealed concentrations less than 1.9 μg/kg for enrofloxacin, 75.5 μg/kg for chlortetracycline.CONCLUSION: The method was successfully applied to monitor 6 veterinary antibiotics from 51 field incurred agricultural soil samples in 17 provincial areas throughout the Republic of Korea. The developed method was simple, easy, and versatile and can be used for monitoring various veterinary antibiotics in soil.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2017.04a
• /
• pp.89-89
• /
• 2017

감자 재배 기계화를 위한 전자동 감자 파종기의 기구적인 개념 설계를 수행하고, 시작기를 제작하였다. 시작기의 성능평가를 통해 기계화에 적합한 감자 재배양식에 대한 연구 필요성이 대두되었다. 본 연구의 목적은 감자 재배 양식에 따른 씨감자 소요량 및 종묘비 금액을 측정하여 기계파종의 경제성 분석함에 있다. 기존의 국내 관행적 감자 재배 작형별 재배방식은 1줄 재배의 경우 재배 형식이 둥근두둑 방식이고 2줄 재배의 경우 평두둑 방식을 채택하고 있다. 기존의 국내 관행적 감자 재배 작형별 재배방식은 1줄 재배의 경우 재배형식이 둥근두둑 방식이며, 2줄 재배의 경우 평두둑 방식을 채택하고 있다. 본 연구에서는 감자 파종기를 이용한 기계화 재배의 경우 평두둑으로 2줄 재배를 안으로 채택하였다. 본 연구는 공시품종인 수미를 이용하여 봄 재배 형식으로 강릉 재배단지에서 실시하였다. 감자 파종은 2016년 3월 31일에 실시하였으며, 재배기간 92일을 소요하여 수확은 2016년 6월 30일에 하였다. 기계파종의 경우 두둑형식은 평두둑 2줄 재배양식 흑색비닐(파종구 세절) 파종 방법으로 전자동 기계파종을 실시하였고, 인력 파종의 경우 기계 파종과 동일한 방식으로 인력으로 실시하였다. 기존의 재래적 방식인 관행파종은 두둑형식은 외줄 1줄 흑색비닐(유공) 파종 방법으로 인력파종을 실시하였다. 관행 파종 방법은 이랑사이 75-80cm, 주간거리 20-25cm, 흙덮기 8-12cm로 재식밀도는 5,000-5,300주/10a로 씨감자 160kg/10a 소요하여 파종하였다. 전자동 감자 파종기를 이용한 기계 파종 재배와 관행 파종 재배 방식과 비교하여 씨감자 소요량 및 종묘비 금액을 비교하였다. 기계파종의 경우 씨감자 절단을 2절로 한 파종 방법의 경우 종자 소요량은 370 kg/10a 이고, 2절과 4절 방법을 혼합한 파종은 204kg/10a, 4절 파종의 경우 185 kg/10a 으로 기존의 관행 파종의 결과인 160 kg/10a 에 비하여 각각 231%, 127%, 116%로 씨감자가 더 소요 되었다. 씨감자 가격은 2016년을 기준 20 kg 당 30,740원으로 계산하였을 경우 파종에 소요된 종묘비는 기계파종의 경우 감자밭 10a에 대하여 씨감자 2절 파종 절단의 경우 569,172원, 2절과 4절 혼합 파종은 312,961원, 4절 절단 파종의 경우 284,586원으로 관행 파종 245,920원으로 나타났다. 기계 파종 시 씨감자 절단 파종 방법에 따라 관행파종 대비 씨감자 종묘비가 16-131% 증가하였다. 하지만 이는 인력파종에 드는 인건비를 제외한 종묘비만 계산한 경제성 분석이므로, 종합적인 경제성 분석은 기계파종기 구입비용 및 투입된 노동력을 고려한 경제성 분석이 추가적으로 필요하다.

• The Korean Journal of Applied Statistics
• /
• v.1 no.2
• /
• pp.34-44
• /
• 1987

In order to estimate the optimum fertilizer level for rice, a major food crop, the experimental results obtained from the fertilizer trials conducted at 642 experimental sites(farmers' fields) throughout the country for the period from 1976 to 1979 were examined. Since non-significant interactions among fertilizers have been ovserved from the past experiences, only thirteen treatments(combinations of fertilizer levels) for the experiments as given in the Table 1 were chosen such that simple response curves can be fitted with independent variables being N, $P_2O_5, and K_2O$. Weighted combining analysis of variance was also carried out for each type of paddy fields to test the significance of Treatments $\times$ Experimental sites interaction, and highly significant variability in response to treatments among experimental sites in the same type of paddy fields was observed in most types of fields. For the types of paddy fields where the treatments $\times$ experimental sites interaction was not significant, separate response curves for N, $P_2O_5, and K_2O$ were estimated on the basis of the mean yields of rice, and common values of the optimum levels of fertilizers were extimated thereform. When the interaction is significant, response curves were fitted for each experimental sites. The average fertilizer doses estimated for the types of paddy fields based on the individual sites are given in Tables 7-1 and 7-2.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.9
• /
• pp.1313-1319
• /
• 2010

Rice cultivars of Goami2 (G2), Baegjinju (BJJ), and Sulgaeng (SG) with different amylose contents were developed by mutation breeding via N-methyl-N-nitrosourea (MNU) treatment to Ilpumbyeo (IP), high japonica rice. They were identified by different appearances such as grain size, color, and shape. In this experiment, the compositional and physical qualities of those cultivars were examined. The G2 rice classified as a high-amylose rice cultivar was significantly higher in its non-digestable carbohydrates contents. Linoleic and oleic acid were composed of 70~75% of all fatty acids composition regardless of milled and brown rice, except G2 rice in which palmitic acid was the major fatty acid followed by linoleic acid and oleic acid in order. Major amino acids were aspartic acid, glutamic acid, and hydroxy lysine. It was found that cysteine contents were higher in the cultivars of endosperm mutant rice. The DSC analysis revealed that enthalpy was the highest in BJJ followed by SG, IP, and G2 rice. The lowest enthalpy of G2 might be attributable to the higher amylose content. Ilpumbyeo in its cooked rice form showed the highest in Toyo value and less in hardness, but G2 was vise versa. Results of gelatinization and cooked rice properties suggest that G2 was less suitable for cooked rice, but has a potential for functional ingredients from nutritional point of view. The BJJ and SG could be used for traditional cooking as well as for processed foods.

• Korean Journal of Environmental Agriculture
• /
• v.24 no.4
• /
• pp.334-340
• /
• 2005

This experiment was conducted to evaluate the nutrient loss and to assess the eutrophication into small stream by intensive rains in the steeped cornfield during cultivation. The crop cultivated was a soiling com (DW5969), and the experimental plots were divided into two parts that were 10 and 18% of slope degrees. The amount of T-N and T-P loss was calculated by analysis of surface run-off water quality, and was investigated the effect of eutrophication to small stream as a part of life cycle assessment (LCA) methodology application. For the surface run-off water quality, EC and T-N values were highest in first runoff event as compared to the other events and maintained the stage state with litter variations at every hour during the runoff period except for EC in the slope 18%. However, T-P concentration has been a transient stage after runoff event of July 27. Total surface run-off ratio was not significantly different with slope degrees, but amount of T-N and T-P losses at 18% of slope were high as $5.96kg\;ha^{-1}\;and\;0.65kg\;ha^{-1}$ as relative to 10% of slope degree, respectively. Furthermore, T-N losses from run-off water in the sloped cornfield 10 and 18% were approximately 9.8 and 12.5% of the N applied as fertilizer when the fertilizer applied at recommended rates after soil test, respectively. For the eutrophication impact to the small stream, it was shown that $PO_4$ equivalence and Eco-indicator value at 18% of slope degree were greater as much $6.11kg\;ha^{-1}$ and 0.81 as compared to the slope angle 10%, respectively. Therefore, it was appeared that each effect of nutrient losses, eutrophication and Eco-indicator value was enhanced according with higher slope degree.

• Research in Plant Disease
• /
• v.23 no.4
• /
• pp.314-321
• /
• 2017

Acidovorax valerianellae had been reported a causal agent of bacterial black spot disease on corn salad in France, 2003 and on watermelon in Korea 2011. In this study, difference in host specificity between 2 groups, corn salad strains and watermelon strains, of Acidovorax valerianellae was recognized and compared. In the pathogenicity test, all 5 watermelon strains showed pathogenicity on the 6 Cucurbitaceae plants but not on corn salad, whereas 4 corn salad strains showed pathogenicity only on the corn salad. Utilization of Biolog substrates was different between watermelon strains and corn salad strains on 4 substrates, Malonic Acid, ${\alpha}-Hydroxybutyric$ Acid, ${\alpha}-Keto$ Butyric Acid, and Glycyl-L Glutamic Acid. The phylogenetic tree built with the 16S rDNA sequences showed that all of A. valerianellae stains was grouped into 1 clade separating from the other species of Acidovorax genus. Within A. valerianellae clade, watermelon strains and corn salad strains were separated into 2 sub-groups. REP-PCR analysis also separated the two groups. Host specificity, substrate utilization, and some genetic characteristics suggested that there are two pathogenic groups, watermelon group and corn salad group in A. valerianellae.