• Korean Journal of Environmental Agriculture
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• v.8 no.1
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• pp.1-6
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• 1989

This study was performed to reveal the heavy metal contents in apple leaves, and to estimate the correlation between contents of heavy metals of orchard lands and those of apple leaves. For this experiment, the apple leaves were collected from 58 apple orchards in Korea. The results were as follows ; 1. The average heavy metal contents in apple leaves were 26.44(6,23-182,85) ppm in Cu, 0.34 (0.07-0,61) ppm in Cd and 9.47 (0.00-225.50) ppm in Pb. 2. On the simple correlation coefficients between contents of heavy metals of orchard lands and those of apple leaves, all three copper cadmium and lead were positive but cadmium was insignificanfly, correlated. There was no difference among varieties (Ralls, Jonathan, etc) in these results. 3. The 0.1N HCl extraetion proved, was more suitable than the $IN-NH_4OAC$ extraction for describing the relation-Ship between heavy metal contents of apple leaves and those of orchard lands.

• Korean Journal of Weed Science
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• v.4 no.1
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• pp.88-95
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• 1984

The study was intended to analyze the interaction effects of paraquat and oxytluorfen as an orchard herbicide-mixture. Data were prepared from the former report of authors. The algebraic expression for the actions of paraquat and oxyfluorfen on the control percentages of peach orchard weeds, and their interactions were determined from the multiple regression polynomial and plotted in three-dimensional graphs. As a result of treatments by combination of paraquat and oxyfluorfen on the field which was dominated by perennial weeds, the most effective interactions were detected at combination rates of $245\;gHa^{-1}$ paraquat and $470-705\;gHa^{-1}$ oxyfluorfen. However, to develope the long-term weeding-efficacies, the combination rates of paraquat are expected to raise up to $500-700\;gHa^{-1}$, and oxyfluorfen to fit at lower limits of rates, respectively.

• Korean Journal of Weed Science
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• v.6 no.1
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• pp.85-96
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• 1986

From the two differently located orchards (even-site with adult tree and slope-site with young tree), weed emergence and the effect of various orchard herbicides on them were comparatively experimented. Weed emergence was assessed in emergence frequency, biomass, relative frequency, and herbicide responses were checked with the variarions in the above weed emergence characters and the weeding values. Herbicides applied were paraquat, glyphosate, oxyfluorfen, napropamide and ustinex using the recommended rates, respectively. Weeds emerged were 7 life-forms, 23 families and 45 species. Among other families, weeds Umbelliferae, Commelinaceae, Gramineae and Polygonaceae couldn't classified in any similarly correlated cluster. However, according to "1-Q mode cluster analysis" of each herbicide performances, "paraquat or glyphosate" with "napropamide or oxyfluorfen" were selected as the most unrelated herbicide pairs expecting the best combination value in mixture model, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.7
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• pp.968-973
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• 2002

To evaluate the chewing activity of ruminant feeds, four Holstein steers (average body weight $742{\pm}15kg$) were employed. Experimental feeds were four roughages ($NH_3$-treated rice straw, alfalfa hay, corn silage, orchard grass hay) and four concentrate ingredients (cotton seed hull, beet pulp pellet, barley grain, oat grain). Regarding palatability for each experimental feeds which was overviewed during the adjustment period, animals were fed roughages alone, but with 50% $NH_3$-treated rice straw ($NH_3$-RS) for concentrate ingredients. Therefore, all the data for concentrate ingredients was derived by extracting the result per unit obtained from steers fed $NH_3$-RS alone. The experiment was conducted using a 4${\times}$4 Latin square designs for roughages and concentrate ingredients. Experimental feeds were fed during a 10 d adaptation and 2 d chewing data collection during each experimental period. Animals were gradually adjusted to the experimental diet. Dry matter intake (DMI) was restricted at a 1.4% of mean body weight (10.4 kg DM/d). Time spent eating and eating chews per kilogram of DMI were greatest for beet pulp pellet, and lowest for barley grain (p<0.05). Time spent rumination per kilogram of DMI was greatest for $NH_3$-RS, cotton seed hull and orchard grass, but rumination chews were greatest for cotton seed hull and orchard grass except $NH_3$-RS (p<0.05). Roughage index value (chewing time, minute/kg DMI) was 58.0 for cotton seed hull, 56.1 for beet pulp pellet, 55.5 for $NH_3$-RS, 53.1 for orchard grass hay, 45.9 for corn silage, 43.0 for alfalfa hay, 30.0 for oat grain, and 10.9 for barley grain. The ratio of rumination time to total chewing time (eating plus ruminating) was about 72% for the roughages except corn silage (66.9%), and followed by cotton seed hull (69.5%), and ranged from 49.5% to 52.9% for other feeds. Higher percentages of rumination in total chewing time may be evidently indicate the characteristics of roughage. Therefore, this indicate that the chewing activity of concentrate ingredients can be more fully reflects by the ruminating time than total chewing time (RVI), although it is reasonable to define the RVI for roughages.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.298-303
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• 2013

In this study, the installation effects of a windbreak net on reducing wind speed were examined using meteorological observation data. Three automatic weather systems (AWS) were installed at the inside of the windbreak net of an apple orchard along the distance, and one AWS was located at the outside. They were set up on Oct. $25^{th}$, 2012 at the apple orchard of Geochang County, and meteorological data, which were observed at four stations for about 1 year from October 26, 2012 through October 21, 2013, were used for this study. Meteorological variables include air temperature & relative humidity at a height of 1.5 meter, and wind speed & wind direction at a height of 2 meter and 4 meter. These variables were measured and recorded every 60 seconds. The preliminary results of this study was as follows: (1) Daily mean temperature at the inside of the windbreak net was lower than that of the outside by 0.1 through $0.2^{\circ}C$. (2) Daily mean relative humidity at the inside of the windbreak net was higher than that of the outside by 0.7 through 1.7%. (3) As compared to the outside, northerly daily maximum wind speed of the inside of the windbreak net at a height of 2 and 4 meter was reduced by 0.7~1.5 $ms^{-1}$ (30.4~65.2%) and 0.3~0.7 $ms^{-1}$ (10.3~24.1%), respectively.

• Korean Journal of Environmental Agriculture
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• v.36 no.2
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• pp.73-79
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• 2017

BACKGROUND: Carbonized biomass is a carbon-rich solid product obtained by the pyrolysis of biomass. It has been suggested to mitigate climate change through increased carbon storage and reduction of greenhouse gas emission. The objective of this study was to evaluate carbon dioxide ($CO_2$) and nitrous oxide ($N_2O$) emissions from soil after carbonized biomass addition. METHODS AND RESULTS: The carbonized biomass was made from a pyrolyzer, which a reactor was operated about $400{\sim}500^{\circ}C$ for 5 hours. The treatments were consisted of a control without input of carbonized biomass and two levels of carbonized biomass inputs as 6.06 Mg/ha for CB-1 and 12.12 Mg/ha for CB-2. Emissions of $CO_2$ and $N_2O$ from orchard soil were determined using closed chamber for 13 weeks at $25^{\circ}C$ of incubation temperature. It was shown that the cumulative $CO_2$ were $209.4g\;CO_2/m^2$ for CB-1, $206.4g\;CO_2/m^2$ for CB-2 and $214.5g\;CO_2/m^2$ for the control after experimental periods. The cumulative $CO_2$ emission was similar in carbonized biomass input treatment compared to the control. It was appeared that cumulative $N_2O$ emissions were $4,478mg\;N_2O/m^2$ for control, $3,227mg\;N_2O/m^2$ for CB-1 and$ 2,324mg\;N_2O/m^2$ for CB-2 at the end of experiment. Cumulative $N_2O$ emission contents significantly decreased with increasing the carbonized biomass input. CONCLUSION: Consequently the carbonized biomass from byproducts such as pear branch residue could suppress the soil $N_2O$ emission. The results fromthe study imply that carbonized biomass can be utilized to reduce greenhouse gas emission from the orchard field.

• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.209-216
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• 1974

Life history and control methods of Aphanostigma iakusuiense Kishida were studied during April to November, 1974, in the Naju pear orchard area, Cholla Namdo. The results are summarized as follows: 1. More than $60\%$ of wintering eggs were found at the height of 1.5 to 2.0m from the soil surface, with approximately $10\%$ at 0.5 to 1.5m and 1.5 to 2.5m respectively. 2. There was little difference in the size of egg masses and hatching ratio $(12.7-13.7\%)$ between the varieties of host trees, Mansamkil and Kooksoo. 3. Hatching was not observed until April 6, but hatches of $12.8\%$ on April 13 and $90.6\%$ on May 4 were found. 4. During the hatching season in early spring, 8 chemicals were applied to test effectiveness of control. C8514, Metasystox, Acar 338, and Parathion were more effective than either Sevin or Malix for control of this insect. 5. Highest populations of pear phylloxera ocurred from August 20 to September 20 at which time levels of eggs and larvae were simillar in abundance. 6. In tests for control of this insect after in paper bags, DDVP, Loxon, C8514, Sevin, and Binapacryl were more effective than either EPN or Otran. 7. Predacious mite, Protolaelape pygmaeus Miller, and several species of lady beetles (Coccinellidae) preying on this insect as natural enemies were collected. The predation ratio of mites varied according to region: that is 0.77 to $18.6\%$ in Bia Orchard; $7.88-48.7\%$ in Noan Orchard and almost none in Youngsanoo Orchard. 8. The varietal difference in fruit damage by this insect was in the order of Choseng Chuck, Kooksoo, followed by Sin Ko, Mansamkil, Keumchon Choo, and Changsimrang.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.2
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• pp.167-172
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• 1984

The aluminum composition of the citrus orchard soils (volcanic ash soil) in Cheju Island was studied. The content of extractable Al was high, especially for the sub-soil. However the exchangeable Al was relatively low : it was only one-tenth of the extractable Al content. The exchangeable Al of the citrus orchard soils decreased with increasing number of years of cultivation. This has resulted from an increase in pH. The content of the extractable Al of the citrus orchard soils also decreased with the increase in number of years of cultivation. This is related to the fact that the application of phosphate fertilizers led to a reduction in Al activity. Therefore, the extractable Al showed a highly significant correlation with the available phosphorus in the top soil. However it was not significantly affected by phosphates in the sub-soil where the available phosphorus was extremely low. The extractable Al content strongly correlated with the organic matter and pH(NaF) in the sub-soil, but the correlation was less significant in the top soil. This suggests that large amounts of the extractable Al are released from the hydrous oxides of Al and that the organically complexed form in the sub-soil and non-extractable due to the reactions with phosphates applied to the top soil.

• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.22-26
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• 1986

This study was conducted to investigate weed population dynamic in orchard and to establish an appropriate application time for oxyfluorfen. 28 weed species including Persicaria hydropiper was observed to be problem weeds in orchard. P. hydropiper was on single dominant species which increased importance value of 13.7 on May 15 to 60.79 on August 10, followed by Calystegia hederacea, Alopecurus aequalis, Capsella bursa-pastoris, Roripa islandica, Echinochloa crus-galli, Potulaca olearcea, Elusin indica. Simpson's index increase from 0.11 on May 1 to 0.40 of August 10, indicating the dominance of specific weed species. The effective herbicide to control these weeds was oxyfluorfen at 5kg prod./ha applied at pereemergence treatment on March 25, showing more than 90% control for 120 days after application. Preemergence application of oxyfluorfen at 3kg prod./ha on March 25 followed by paraquat 3kg prod./ha applied on June 25 as the foliar application can maintain the clean orchard for a year, showing on of the promising and applicable control system. The most appropriate rate and time for oxyfluorfen seemed to be 5kg prod./ha applied on March 25.

• Korean Journal of Organic Agriculture
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• v.27 no.1
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• pp.77-86
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• 2019

This study was carried out to investigate the effect of legume cover crop culture on earthworm fauna in organic farmland. We compared sod culture with two kinds of legume crops of hairy vetch and crimson clover on organic citrus orchard to natural sod culture and conventional orchards in Jeju Island. We analyzed the soil characteristics and investigated the density of earthworms from the orchards. Organic matter content did not show much difference in soil analysis between organic and conventional orchard. But the biomass of earthworms in organic orchards is 3.8 times to 7.0 times higher than that in conventional cultivated orchards, and individuals of earthworms on organic orchards were 2.3~18 times higher than conventional orchards. The biomass of earthworms on hairy vetch and crimson clover cultivation was 44.8 g, 47.2 g in 2016, and 78.7 g, 31.8 g in 2017, respectively, which were higher than 32.8 g and 9.5 g of those on natural sod cultivation. Through this study, we found that hairy vetch and crimson clover cultivation improve the earthworm occurrence density in the soil on organic citrus orchard.