• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.223-229
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• 1987

This study was carried out to find out the effects of nitrogen dioxide gas on vegetable crops. Chinese cabbage, radish, tomato and cucumber were used for this experiment, and these crops were fumigated with various concentration of nitrogen dixoide gas for 2 hours under the different condition of light and soil water at the vegetable growth stage. The results obtained were as follows. The crops damages measured by percentage of leaf destruction were more severe at the night time fumigation than at the day time, under the full sun condition than under the shading, and at the higher soil water contents than at the low soil water contents. The cucumber plant showed the highest resistance to nitrogen dioxide gas and tomato plant showed the least resistance. As the nitrogen dioxide concentration increased from $0.05mg/{\ell}$ to $0.2mg/{\ell}$, the N contents in leaves of each crops were increased, and the increment of N contents in leaves was higher by fumigation at the night than at the day time. The increment of N contents in leaves showed possive correlation with the percentage of leaf destruction significantly.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.311-316
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• 2010

This study was conducted to investigate the effect of anaerobic fermentation of wheat bran to prevent root-knot nematodes which are infected in plastic house due to over 10 years continuous cultivation of fruits and vegetables. Anaerobic fermentation treatment of wheat bran was done for 20 days by mixture of 2,000 kg fresh wheat bran per 10 are and soil with water in 30 cm soil depth. Chemical treatment of fosthiazate was done by mixture of 6 kg soil for 7 days. Both treatments show suppression of density of rootknot nematodes, especially in anaerobic fermentation treatment. Anaerobic fermentation treatment keeps the low level of root-knot nematode density until 90 days of cultivation and also showed good effect of melon growth. Related with death percentage of melon plant, anaerobic fermentation treatment shows only 3% and also large size of quality fruit but control 65%. Anaerobic fermentation treatment of wheat bran have proved to control the level of root-knot nematodes instead of synthetic chemicals for at least one cropping season and it showed good effect to fruit quality.

• Korean Journal of Environmental Agriculture
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• v.31 no.3
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• pp.205-211
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• 2012

BACKGROUND: Generally, nitrogen (N) fertilization higher than the recommended dose is applied during vegetable cultivation to increase productivity. But higher N fertilization also increases the concentrations of nitrate ions and nitrous oxide in soil. In this experiment, the impact of N fertilization was studied on nitrous oxide ($N_2O$) emission to standardize the optimum fertilization level for minimizing $N_2O$ emission as well as increasing crop productivity. Herein, we developed $N_2O$ emission inventory for upland soil region during red pepper and Chinese milk vetch cultivation. METHODS AND RESULTS: Nitrogen fertilizers were applied at different rates to study their effect on $N_2O$ emission during red pepper and Chinese milk vetch cultivation. The gas samples were collected by static closed chamber method and $N_2O$ concentration was measured by gas chromatography. The total $N_2O$ flux was steadily increased due to increasing N fertilization level, though the overall pattern of $N_2O$ emission dynamics was same. Application of N fertilization higher than the recommended dose increased the values of both seasonal $N_2O$ flux (94.5% for Chinese cabbage and 30.7% for red pepper) and $N_2O$ emission per unit crop yield (77.9% for Chinese cabbage and 23.2% for red pepper). Nitrous oxide inventory revealed that the $N_2O$ emission due to unit amount of N application from short-duration vegetable field in fall (autumn) season (6.36 kg/ha) was almost 70% higher than that during summer season. CONCLUSION: Application of excess N-fertilizers increased seasonal $N_2O$ flux especially the $N_2O$ flux per unit yield during both Chinese cabbage and red pepper cultivation. This suggested that the higher N fertilization than the recommended dose actually facilitates $N_2O$ emission than boosting plant productivity. The $N_2O$ inventory for upland farming in temperate region like Korea revealed that $N_2O$ flux due to unit amount of N-fertilizer application for Chinese cabbage in fall (autumn) season was comparatively higher than that of summer vegetables like red pepper. Therefore, the judicious N fertilization following recommended dose is required to suppress $N_2O$ emission with high vegetable productivity in upland soils.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.1
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• pp.1-13
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• 2009

Understanding the net nutrient balance in a farming system is crucial in assessing the system's sustainability. We quantified N, P and K balances under vegetable organic farming in a Eutric Haplud and in West Java, Indonesia in five planting seasons from 2005 to 2007. The ten treatments and three replications, arranged in a completely randomized block design, included single or combined sources of organic fertilizers: barnyard manure, compos ts or green manures. The organic matter rates were adjusted every planting season depending on the previous crop responses. The result sshowed that the application of ${\geq}20$ t $ha^{-1}$ barnyard manure per crop resulted in positive balances of N, P, and K, except in the second crops of 2006 where potassium balance were -25 to -11 kg $ha^{-1}$ under the treatments involving cattle barnyard manure, because of low K content of these treatments and high K uptake by Chinese cabbage. Application of 20 to 25 t $ha^{-1}$ of plant residue or 5 t $ha^{-1}$ of Tithonia compost also resulted in a negative K balance. Soil available P increased significantly under ${\geq}25$ t $ha^{-1}$ barnyard manure and that under chicken manure had the highest available P. Accordingly, chicken barnyard manure gave the highest crop yield because of relatively higher N, P, and K contents. Plant residues gave the lowest yield due to the lowest nutrient content among all sources. Reducing the use of barnyard manure to 12.5 t $ha^{-1}$ and substituting it with Tithonia compost, Tithonia green manure or vegetable plant residue compost gave insignificantly different yield compared to the application of 25 t $ha^{-1}$ barnyard manure singly. In the long run, application of 25 t ha-1 cattle, goat, and horse manure or about 20 t $ha^{-1}$ chicken manure is recommendable for sustaining the fertility of this Andisol for vegetable production.

• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.50-57
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• 2020

BACKGROUND: Biochar is used in various environmental fields, such as water quality and soil restoration, and affects soil fertility and nutrient cycling. Also, when crops are grown on biochar-applied soil, their characteristics may be affected. Biochar is used especially with commercial vegetable seedlings. METHODS AND RESULTS: The objective of this study was to determine the effects of biochar content in seeding mixes on early growth of lettuce (Lactuca sativa L.), Chinese cabbage (Brassica rapa L.), and red pepper (Capsicum annuum L.). Treatments consisted of a control (0: 10, ratio of biochar to seeding mixes (w/w)), 1: 9 (biochar 10%), 3: 7 (biochar 30%), 5: 5 (biochar 50%), and 7: 3 (biochar 70%). The biochar was made from risk husk and had a C/N ratio of 104. As the mixing ratio of biochar increased, pH increased whereas EC and nitrogen content decreased. The highest phosphorus content was with the treatment of 30% biochar, while there were significant increases in the weight of lettuce seedlings and concentrations of T-N, P₂O₅, K₂O, MgO, and Na with the treatments of 30% and 50% biochar. Although the weight of Chinese cabbage seedlings increased with the treatment of 10% biochar, the increase was not statistically significant. Also, there was an increase in the weight of red pepper seedlings with the treatment of 30% biochar, but the increase was not statistically significant. With increases in the biochar mixing ratio, the K₂O concentration of red pepper seedlings increased, but the concentrations of P₂O₅, CaO, MgO, and Na decreased. It was believed that this was because of absorption inhibition by calcium-phosphate formation in the seeding mixes owing to increased pH. CONCLUSION: In conclusion, adding biochar to seeding mixes is considered to be an important mean for growing healthy vegetable seedlings. More field experiments are needed to verify the effect of biochar on vegetable crop growth over the entire growing season.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.1
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• pp.55-64
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• 1995

This paper presents analytic results of energy sequestered for the forcing cultural Cu- cumber and the others production system with the input-output tables method in the suthern parts of Korea. In this study an attempt is made to evaluate input of direct and indirect energy, output of yield energy and net energy in order to achieve increased energy productivity under P E greenhouse. Cultural practices were grouped soil and soilless with perlite for vegetable production. The results from this study are summarized as follows : 1. Total energy inputs in cucumber production were calculated to be 510 GJ/l0a(di- rect energy : 480 GJ/lOa, indirect energy : 30 GJ/lOa) from soil culture and 440 GJ/ 10a(direct energy : 420 GJ/lOa, indirect energy : 20 GJ/lOa) from soilless culture in perlite hydroponics. 2. Energy outputs from cucumber and biomass were 7 GJ/lOa and 120 GJ/lOa at a uniform rate respectively. 3. Heating fuel as diesel is a major energy inputs approaching 90% of the total energy requirements for cucumber production. 4. Net energy in cucumber production was calculated to be 503 GJ/lOa from soil cul- ture and 431 GJ/lOa from soilless culture. Net energy productivity was maintained costantly as 0.98. 5. Energy productivity in cucumber was calculated to be 0.029 kg/MJ from soil culture and 0.043kg/MJ from soilless culture, while energy efficiency was 0.012 and 0.015 respectively. It is expected that a soilless cultural production system seems to be reduc- tive in seguestered energy input by 13%.

• Korean Journal of Medicinal Crop Science
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• v.12 no.5
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• pp.355-359
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• 2004

A survey was conducted during $April{\sim}May$ 2004 to determine the occurrence and population density of plant-parasitic nematodes in ginseng (Panax ginseng C.A. Meyer) growing fields, in major ginseng growing regions of Chungbuk, Chungnam, Gyeongbuk and Kyongki provinces. The survey revealed presence of eleven species of plant-parasitic nematodes namely, Criconemoides morgensis, Ditylenchus destructor, Helicotylenchus dihystera, Meloidogyne incognita, M. hapla, Paratylencgus lepidus, Pratylenchus penetrans, Psilenchus hilarulus, Trichodorus similis, Tylenchorhynchus claytoni and Xiphinema americanum. Frequency and density of each species were highly variable. M. incognita and M. hapla were the predominant species, their infestation observed in 46.3 and 39.4% fields with an average density of $78{\sim}254\;and\;76{\sim}211$ nematodes per $300\;cm^3$ soil, respectively. Whereas, T. similis and X. americanum were rarely observed; only in 2.3 and 1.8% of surveyed fields and their density was $10{\sim}17\;and\;7{\sim}10$ individuals per $300\;cm^3$ soil, respectively. They are recorded herewith for the first time from ginseng fields of Korea. In nematode-infestated fields, stunted plant growth with chlorotic leaves, and wilted plants were observed in patches.

• Mycobiology
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• v.30 no.1
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• pp.27-30
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• 2002

Two-hundred two yeast strains were isolated from rhizosphere(87 strains) and nonrhizosphere(115 strains) areas of potato, maize, vegetable marrow, and cabbage plants. On the basis of 26 morphological and physiological properties, the isolated yeast strains were assigned to 9 genera and 15 species. Trichosporon beigelii, Kluyveromyces marxianus and Torulaspora delbrueckii were the dominant species. Cryptococcus humicolus and Candida tropicalis were represented by considerable numbers of strains. Of low occurrence were Saccharomyces cerevisiae and Candida blankii. Other yeast species were represented by single or two strains. Total counts of yeast cells per gram dry soil ranged from $1.1{\times}10^3$ to $6.6{\times}10^3$ in soil samples of rhizosphere areas and from $6.5{\times}10^2$ to $5.6{\times}10^3$ in soil samples of nonrhizosphere areas. Types of the tested plants affected not only the total counts of yeast cells but also spectra of yeast species. Relationships of age of potato plant, moisture contests of soil samples, and its pH values and total counts of yeast cells were discussed.

• Journal of Environmental Health Sciences
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• v.11 no.2
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• pp.29-39
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• 1985

This experimental study was carried out to evaluate the improvement of rural privys and to develop the system of the three septic tank privy. For this study, 42 samples of excreta, 42 samples of soil and 26 samples of vegetables were drawn out of the conventional privys while 26samples of excreta, 26samples of soil and 26samples of vegetables out of the three septic tank privys from five villages in Chun Song County. Kang Won Province for the period from 22th August to 13th October, 1984. The major findings are as follows : 1. Positive cases of helminthes are found 41 out of 42(97.6%) excreta of the conventional privys whereas those from the three septic tank privys are found 2 out of 26 (7.7%). Average numbers of helminthes from the excreta of the conventional privys are 4.4 whereas those from the three septic tank privys are 1.1. 2. Positive cases of helminthes are found 33 out of 42 (78.6%) soil of the conventional privys whereas those from the three septic tank privys are found 20 out of 26(76.9%). However, this difference does not reveal statistical significance (P>0.01). Average numbers of helminthes from the soil of the conventional privys are 2.3 whereas those from the three septic tank privys are 1.7 and the difference in total number of helminthes reveals statistical significance (P<0.05). 3. Positive cases of helminthes from vegetable samples drawn out of the conventional privys are found 13 out of 26(50.0%) whereas those froin the three septic tank ptivys are found 10 out of 26(38.5%). Average numbers of helminthes from vegetable samples drawn out of the conventional privys are 1.1 whereas those from the three septic tank privys are 0.7. However, these differences in both positive rates and total numbers of helminthes do not reveal statistical significance (P>0.05).

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.10a
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• pp.51.2-51
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• 1999