• Korean Journal of Soil Science and Fertilizer
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• v.26 no.2
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• pp.103-110
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• 1993

This study was made to evaluate the chemical properties of 481 farmers' orchard fields in An-Seong area. And the reasonable ferilizer rates were recommended utilizing the result of soil analysis. The results are summarized as follows : 1. As the soil fertility status of collected soil samples were evaluated on the basis of temporary optimal range for each soil chemical properties, 12.7 to 49.6% of the total 481 farmers' fields were range for soil improvement. 2. The contents of chemical component have a tendancy to decrease with depth gradually from surface to subsoil. 3. According to the relationship between the contents of soil component in subsoil and those in surface soil, the fertility condition of subsoil could be estimated on the basis of analysis data of surface soil. 4. The multiple regression equation for pear yield prediction to the organic matter and exchangable calcium contents in the soil were obtained. 5. Referring the average value, distribution ratio compared to the optimum level for each soil chemical properties and standard fertilizer rate, the soil fertility status could be categorized as "High" "Medium" and "Low". For each category, the recommended amounts for NPK and organic matter application were established. 6. The recommended rates through soul fertility diagnosis were less than farmer's dosage in the range 7.1~7.7 kg/10a for N, 0.8~11.5 kg/10a for $P_2O_5$, 7.1~19.9 kg/10a for $K_2O$ and 90~116 kg/10a for lime.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.2
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• pp.11-18
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• 2018

Biochar 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 various biochars addition. The biochars were produced by pyrolysing pear branch, rice hull and bean straw at $400{\sim}500^{\circ}C$. The treatments were consisted of a control without input of biochar and three type biochars input as 5.0 Mg/ha. Emissions of $CO_2$ and $N_2O$ from upland soil were determined using closed chamber for 8 weeks at $25^{\circ}C$ of incubation temperature. It was shown that the cumulative $CO_2$ were 207.1 to $255.2g\;CO_2/m^2$ for biochar input treatments and $258.6g\;CO_2/m^2$ for the control after experimental periods. The cumulative $CO_2$ emission was slightly decreased in biochar input treatment compared to the control. It was appeared that cumulative $N_2O$ emissions were $2,890.6mg\;N_2O/m^2$ for control, 379.7 to $525.2mg\;N_2O/m^2$ for biochar input treatment at the end of experiment. All biochar treatments were found to significantly reduce $N_2O$ emission by 82~87%. Consequently the biochar from byproducts such as pear branch, rice hull and bean straw could suppress the soil $N_2O$ emission. The results from the study imply that biochar can be utilized to reduce greenhouse gas emission from the upland field.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.2
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• pp.281-286
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• 2014

This study was carried out to develop Yakju, a new kind of Korean traditional rice wine added with bamboo ethanol extract and characterized by containing various health benefits. The wine with bamboo ethanol extract was fermented by adding ginger and pear to improve flavor and quality. Several quality characteristics and physiological functionalities of Yakju were investigated. When bamboo ethanol extract was added to Yakju, the pH level decreased compared to that of the control. However, total acidity and soluble solid levels were higher than those of the control. The alcohol content of Yakju added with bamboo ethanol extract was slightly higher than that of the control. In examining the colors of Yakju containing bamboo ethanol extract, L value was lower than that of the control, whereas b value and brownness were higher. Various organic acids such as citric acid, malic acid, succinic acid, lactic acid, and acetic acid were determined, and the main organic acid among them was lactic acid. Various free sugars such as sorbitol, glucose, and fructose were detected and glucose was the most abundant. Total polyphenol content of Yakju added with bamboo ethanol extract was lower than that of the control. Further, electron-donating ability ranged from 23.8~40.0%, which was higher than that of the control. Nitrite scavenging ability of Yakju added with bamboo ethanol extract ranged from 15.2~36.4%, which was higher than that of the control at pH 6.0. Sensory evaluation of Yakju showed that bamboo ethanol extract+ginger as well as bamboo ethanol extract+ginger+pear treatment significantly increased flavor, taste, and overall acceptance compared to the others.

• Korean Journal of Organic Agriculture
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• v.27 no.1
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• pp.33-44
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• 2019

This study was initiated to find possibility of substitute of gibberellin acid and to prevent negative girdling effect such as slow growth of 'Niitaka' (Pyrus pyrifolia Nakai) trees, a major pear cultivar, at harvest and at 60-, 90-, and 120-d after storage. Seasonal wiring with 3.0-mm-diameter were applied on the main branch at 70, 80, 90, 110, and 130 days after full bloom (DAF) to compare the fruit quality and storability. Fruit weight and sugar contents were the greatly increased by the wiring treatment at 110 DAF, with the lowest values observed for the wiring at 70 DAF. All the wiring treatments reduced fruit acidity but did not affect fruit firmness. a-value on fruit skin was the highest for wiring at 110 DAF and 130 DAF, advancing fruit ripening. The lowest fruit weight loss was occurred at wiring at 110 DAF. a-value on fruit skin was the highest for wiring at 90 DAF and 110 DAF. Wiring at 80 DAF the most increased floral bud diameter, resulting in the lowest L:D ratio of 1.74 observed. As for the mineral nutrients concentrations of floral buds, the concentration of K (0.63%) and Mg (0.31%) were the highest after 80 DAF wiring treatment, whereas Ca and P concentrations did not differ among treatment plots. The leaf K concentrations was the highest in the 130-day wiring treatment (0.76%) and in the control plot (0.78%), whereas there was no significant difference in the concentrations of either Ca or P among treatment plots. Short periods of wiring increased foliar Mg concentrations. In floral buds, carbohydrates showed a tendency for accumulating at a lower concentrations (7.75%) after 70 DAF wiring treatment, which was a relatively short treatment period. On the other hand, the carbohydrate concentrations in leaves showed a tendency for accumulating at lower concentrations after 130 DAF wiring treatment (2.51%), which is a long treatment period, and in the control plot (2.43%). Wiring increased the size and sugar content of fruits, and influenced fruit storability. For the wiring treatment period was delayed, the carbohydrate concentration in flower buds showed curvilinear correlation and the negative correlation with the carbohydrate in leaf tissue.

• Food Science and Preservation
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• v.17 no.2
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• pp.169-173
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• 2010

Although fruit grown under sustainable farming conditions is believed to be healthier for humans than is fruit grown by conventional cultivation, little scientific information on the characteristics of fruit produced using these two farming systems is available in Korea. Therefore, weinvestigated fruit quality, total polyphenolic contents, and anti-oxidant activities in 'Niitaka' pears grown under sustainable and conventional farming management systems. Treatmentsincluded use of a chitin compost admixed with liquid chitin fertilizer (plot A), and use of a chitin compost admixed with liquid chitin fertilizer treated by infrared radiation (plot B). Plots C and D used conventional management systems. Fruit qualities at harvest differed between both sustainable plots A and B and the conventional plots C and D. The average values of firmness and total polyphenolic content in fruit harvested from sustainable plots were not significantly greaterthan those of fruit grownin conventional plots, after 60 days of storage. Fruit grown in all plots had low polyphenol oxidase (PPO) activity at harvest but this increased during storage. Fruit from sustainable plot B showed an increased electron donating ability compared with fruit grown using the other systems.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.25-35
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• 2010

The periodic application effects of two different herbicides on soil physical properties were observed in a slightly hilly orchard of pear tree located on the southestern flank of the Palbong Mountain in Gongju Chungnam : (1) bare surface vegetation; (2) glyphosate-treated plot; (3) paraquat-treated plot. The slope of experimental plots ranged from 5.5%to 10.2%at an altitude of 125 mand 896 $m^2$ ($28m{\times}32m$) in area. The total respective rainfall events were 47, 52, 52 times during experimental period from 2006 to 2008, while approximately 65 percent of daily rainfall intensity from2006 to 2008 was less than 20 mm a day. The organic matter contents on the surface 15 cm soil ranging from1.23%to 1.84%in 2006 were changed into from1.35 %to 2.28%in 2008 in the order of control > glyphosate > paraquat > bare plot in 2008, indicating that the herbicide treatment influenced the accumulation organic matter in soil. The changes in soil particle contents showed that the loss of soil particles in top 5 cm soil depth was greater in a bare soil than in other treatments such as control, glyphosate, and paraquat-treated plot. The net changes in the bulk densities showed that there were little variations between May of 2006 and Nov. of 2008 even though there were some losses of the soil particles. The soil strength of the glyphosate-treated bare plots was much greater than those of other plots such as control, glyphosate, and paraquat plots. However the soil strengths in control plots were lower than those in the plots of glyphosate and paraquat treated ones.

• Korean Journal of Environmental Biology
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• v.27 no.1
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• pp.40-47
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• 2009

Heavy reliance on organosynthetic chemical methods to control agricultural pest tends to deteriorate and lower fertility of soil. We studied annual occurrence of earthworm in environment-friendly agroecosystem and attempted to determine the degree of soil contamination. Candidate bioindicators of earthworm in agroecosystem were selected through analysis of earthworm diversities. Depending on the degree of pesticide use, the fields were devided into conventional, less-pesticide, pesticide free, and organic fields. A nearby field not in agricultural use was chosen as a control. This study was carried out in the greenhouses (lettuce and grape) in 2006 and in orchards (apple, pear, peach, citrus and grape) in 2007. Earthworm was collected from 50 $\times$ 50 $\times$ 10 cm$^3$ of respective soil. We found 11 species from 5 genera and 3 families, and 12 species from 4 genera and 3 families in the greenhouses and in orchards, respectively. The contents of organic matter in soil in the greenhouses were variable but quite less so in orchards. Amynthas heteropodus occurred most frequently in both sites suggesting that it could be adopted as a bioindicator in agroecosystem in Korea.

• Korean Journal of Organic Agriculture
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• v.10 no.3
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• pp.67-77
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• 2002

This study was conducted to investigate an effects on ago-chemical alternative materials such as the wood vinegar, a lactic acid bacteria serum, the fermented plant juice, the brown rice vinegar and a Chitosan used for amount and qualities of fruits and to examine the pest protection efficiency for their uses in the apple and pear orchard farms. An apple yields in the orchard cultivated with using the ago-chemical alternative materials without appling the fertilizer and pesticides were decreased at 56% relative to the conventional farming practice method. Also, it was indicated that there was difficult to produce the fruits with marketability because the small sizes of fruits were produced. For the quality of fruits, the brix of apple produced in the orchard cultivated with using the ago-chemical alternative materials was similar, but Vitamin C content was greater than that of the conventional farming practice method. As a results of treating with the wood vinegar, a lactic acid bacteria serum, the fermented plant juice, the brown rice vinegar and a Chitosan instead of applying pesticides, the fruit disease in the Chitosan treatment was a little decreased, but was great occurred in the other treatments compared with the conventional farming practice mehod. However, it observed that brix and Vitamin C content of apple produced in the Chitosan, brown rice vinegar, fermented plan juice and fish amino acid treatments and in the Chitosan, brown rice vinegar, charcoal power and peat moss treatments were greater than those of the conventional farming practice method, respectively. Over all, it considered that there was very difficult to manage the orchard depended on the ago-chemical alternative materials without appling the chemical fertilizer and pesticides in the apple orchard, but it might be proper to use the ago-chemical alternative materials as an auxiliary means to decrease the appling amount of chemical fertilizer and pesticides. Furthermore, the general effects on the ago-chemical alternative materials to the perennial fruits should be investigated with considering the changes of soil fertility, soil microbial status and natural enemy creatures after treating them for a long time.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.90-95
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• 1998

Soil residues of paraquat (1,1-dimethyl-4,4-dipyridinium dichloride) were determined in apple, pear, grape, and peach orchards for which 15 sites each were selected randomly from the corresponding large-scale production area throughout the country. Strong adsorption capacity measured using wheat bioassay (paraquat concentration required to reduce 50% root growth of wheat, SAC-WB) was also investigated on the orchard soils and the paraquat residue level was calculated against total SAC-WB values (SAC-WB value + paraquat residue). Average bound residue of paraquat on the 60 sites was 6.9 ppm, while paraquat residue in apple orchard reached 20.2 ppm which was the highest among the orchards and was almost double as compared with those in the other three orchards. Loosely bound residue of paraquat determined on the bound residue high top five soils occurred less than 0.5 ppm detection limit. Average SAC-WB value was 276.1 ppm and there were no any correlations between the SAC-WB value and clay content, organic matter content, and cation exchange capacity of the orchard soils. Paraquat residue level of the orchard soils against total SAC-WB recorded 2.43%.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.308-314
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• 2012

In order to monitor the residual pesticides in environment friendly agricultural commodities, fruits and fruiting vegetables. Twenty-five agricultural commodities were collected twice in May and August 2011 from nine environment friendly agricultural commodities-selling supermarkets and retail stores located in eight major cities in Korea. The number of each agricultural commodity collected, 555 samples in total, was 152 organic agricultural products, 202 pesticide-free agricultural products and 201 low-pesticide agricultural products. Pesticide residues in samples were analyzed by multiresidue method for 245 pesticides using a GC-ECD/NPD and an HPLC-DAD/FLD and the peaks suspected as pesticides were identified with a GC/MSD. As a result of pesticide residue analysis, three pesticides, bifenthrin, EPN and chlorpyrifos, were detected from four samples including apple, representing a detection rate of 0.72%. The residue levels of the four pesticide-detected samples were less than their maximum residue limits (MRLs) but one pesticide EPN detected from pear exceeded its legible criterion of one twentieth MRL. Estimated daily intakes of the pesticides detected from fruits and fruiting vegetables were less than 0.76% of their maximum permissible intake.