• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.297-306
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• 2021

To select rice (Oryza sativa L.) cultivars suitable for forage-rice double cropping system, the growth and grain quality of four early maturing rice cultivars (Joun, Jopyeong, Haedamssal, and Unkwang), and the chemical properties of soils were investigated under single- (fallow-rice) and forage-rice double-cropping systems in paddy fields in Miryang, southern Korea. The soil where two forage crops [Italian ryegrass (Lolium multiflorum Lam.) and oat (Avena sativa L.)] were cultivated during winter had a slightly lower pH; an increase in total nitrogen (T-N), K, Ca, and Na contents; and a slight decrease in organic matter and available P₂O₅ contents, compared with the soil fallowed during winter. This shows that the chemical properties of paddy soils can be improved by winter forage cropping. At the heading stage, the culm length, panicle length, panicle number, and leaf color of all cultivars, except for Haedamssal, were generally higher under double-cropping than under single-cropping. For Haedamssal, the culm length and leaf color did not differ between the cropping systems, but the panicle length was slightly shortened and its panicle number increased under double-cropping. After harvest, the yield of milled rice decreased for all cultivars except Haedamssal, but increased in Haedamssal under double-cropping. The head rice rate was slightly higher under double cropping, particularly in Jopyeong and Haedamssal, than under single-cropping. The protein content of milled rice under double cropping was higher and its amylose content was similar or slightly lower compared to those of rice under single cropping, resulting in decreased Toyo values for rice under double-cropping. The pasting temperature did not differ significantly between the cropping systems. However, Haedamssal had a low pasting temperature but a high Toyo value under double cropping, compared to the other three cultivars, suggesting that its palatability is relatively high. Furthermore, panicle number increased and milled rice yield did not decrease, even under double cropping. Therefore, Haedamssal seems to be the best cultivar for paddy-based double cropping with forage crops.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.400-412
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• 2023

In this study, the biogeochemistry management (BGC-MAN) model was applied to North and South Korea pine and oak forest stands to evaluate the Net Primary Productivity (NPP), an indicator of forest ecosystem productivity. For meteorological information, historical records and East Asian climate scenario data of Shared Socioeconomic Pathways (SSPs) were used. For vegetation information, pine (Pinus densiflora) and oak(Quercus spp.) forest stands were selected at the Gwangneung and Seolmacheon in South Korea and Sariwon, Sohung, Haeju, Jongju, and Wonsan, which are known to have tree nurseries in North Korea. Among the biophysical information, we used the elevation model for topographic data such as longitude, altitude, and slope direction, and the global soil database for soil data. For management factors, we considered the destruction of forests in North and South Korea due to the Korean War in 1950 and the subsequent reforestation process. The overall mean value of simulated NPP from 1991 to 2100 was 5.17 Mg C ha^-1, with a range of 3.30-8.19 Mg C ha^-1. In addition, increased variability in climate scenarios resulted in variations in forest productivity, with a notable decline in the growth of pine forests. The applicability of the BGC-MAN model to the Korean Peninsula was examined at a time when the ecosystem process-based models were becoming increasingly important due to climate change. In this study, the data on the effects of climate change disturbances on forest ecosystems that was analyzed was limited; therefore, future modeling methods should be improved to simulate more precise ecosystem changes across the Korean Peninsula through process-based models.

• Journal of Mushroom
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• v.18 no.1
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• pp.1-9
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• 2020

Mycorrhiza refers to the association between a plant and a fungus colonizing the cortical tissue of the plant's roots during periods of active plant growth. The benefits afforded by plants from mycorrhizal symbioses can be characterized either agronomically, based on increased growth and yield, or ecologically, based on improved fitness (i.e., reproductive ability). In either case, the benefit accrues primarily because mycorrhizal fungi form a critical linkage between plant roots and the soil. The soilborne or extramatrical hyphae take up nutrients from the soil solution and transport them to the root. This mycorrhizae-mediated mechanism increases the effective absorptive surface area of the plant. There are seven major types of mycorrhizae along with mycoheterotrophy: endomycorrhizae (arbuscular mycorrhizae, AM), ectomycorrhizae (EM), ectendomycorrhizae, monotropoid, arbutoid, orchid, and ericoid. Endomycorrhizal fungi form arbuscules or highly branched structures within root cortical cells, giving rise to arbuscular mycorrhiza, which may produce extensive extramatrical hyphae and significantly increase phosphorus inflow rates in the plants they colonize. Ectomycorrhizal fungi may produce large quantities of hyphae on the root and in the soil; these hyphae play a role in absorption and translocation of inorganic nutrients and water, and also release nutrients from litter layers by producing enzymes involved in mineralization of organic matters. Over 4,000 fungal species, primarily belonging to Basidiomycotina and to a lesser extent Ascomycotina, are able to form ectomycorrhizae. Many of these fungi produce various mushrooms on the forest floor that are traded at a high price. In this paper, we discuss the benefits, nutrient cycles, and artificial cultivation of mycorrhizae in Korea.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.171-177
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• 2012

Pepper seedlings of 6-leaf stage were inoculated with cell suspension of Xanthomonas euvesicatoria 1523 7 days after the application of Bion-M by soil-drenching. Disease severity in the treatment with 20 ${\mu}g\;mL^{-1}$ of acibenzolar-S-methyl, with which Bion-M was composed, was 19%, whereas that of the untreated control was 75%. The resulting control value of acibenzolar-S-methyl was calaulated as much as 74.7%. The control value of acibenzolar-S-methyl was dependent with the applied concentrations and ranged 29.3% to 49.3% at 4.0 and 0.8 ${\mu}g\;mL^{-1}$ of acibenzolar-S-methyl, respectively. Phytotoxicity was observed at 20.0 ${\mu}g\;mL^{-1}$, as lower leaves became to be yellowed and defoliated. The cell density of inoculum suspension of X. euvesicatoria 1523 affected the control value of acibenzolar-S-methyl. With optical density (O.D.) of 0.5 the control value of 4.0 ${\mu}g\;mL^{-1}$ of acibenzolar-S-methyl was 86.0%. However, the control value improved as high as 97.8% at the O.D. value of 0.1. The control value was 75.0% in adult plant of pepper, when acibenzolar-S-methyl was treated by soil-drenching 7 days before inoculation with cell suspension of X. euvesicatoria 1523. The control effect of acibenzolar-S-methyl on pepper bacterial spot was obtained in pepper field, showing that the control value at 10.0 ${\mu}g\;mL^{-1}$ was 71.2%.

• Korean Journal of Organic Agriculture
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• v.24 no.4
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• pp.833-847
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• 2016

Drought stress is a major agricultural limitation to crop productivity worldwide, especially by which leafy vegetables, plant leaves eaten as vegetable, could be more lethal. The study was carried out to know the effect of drought tolerance plant growth promoting bacteria (PGPB) on water stress of kale seedlings. A total of 146 morphologically distinct bacterial colonies were isolated from bulk soil and rhizosphere soil of leafy vegetables and screened for plant growth promoting microbioassay in greenhouse. Out of them the isolate SB19 significantly promoted the growth of kale seedlings in increasement of about 42% of plant height (14.1 cm), 148% of leaf area ($19.0cm^2$) and 138% of shoot fresh weight (1662.5 mg) attained by the bacterially treated plants compared to distilled water treated control (9.9 cm, $7.7cm^2$, 698.8 mg). Shoot water content of SB19 treated kale seedlings (1393.8 mg) was also increased about 152% compared with control (552.5 mg). The SB19 isolated from bulk soil of kale plant in Iksan, Korea, was identified as species of Bacillus based on 16S rRNA gene sequencing analysis. We evaluated the effect of drought tolerance by the Bacillus sp. SB19 on kale seedlings at 7th and 14th days following the onset of the water stress and watering was only at 7th day in the middle of test. In the survey of 7th and 14th day, there were mitigation effect of drought stress in kale seedlings treated with $10^6$ and $10^7cell\;mL^{-1}$ of SB19 compared to distilled water treated control. Especially, there were more effective mitigation of drought damage in kale seedlings treated with $10^7cell\;mL^{-1}$ than $10^6cell\;mL^{-1}$. Further, although drought injury of bacterially treated kale seedlings were not improved at 14th day compared with 7th day, drought injury of $10^7cell\;mL^{-1}$ of SB19 treated kale seedlings were not happen rapidly but developed over a longer period of time than $10^6cell\;mL^{-1}$ of SB19 or control. The diffidence of results might be caused by the concentration of bacterial suspension. This study suggests that beneficial plant-microbe interaction could be a important role of enhancement of water availability and also provide a good method for improving quality of leafy vegetables under water stress conditions.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.119-123
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• 1997

This study was performed to evaluate the influence of composting process with an intermittent aeration on the variation of rhizosphere soil temperature, $CO_2$ and $NH_3$ release, and the growth reponse of tomato plantlet in traditional and composting greenhouse. As the temperature of composting materials increased, rhizosphere soil temperature in 30cm depth rose up to $32^{\circ}C$ at one week after introduction. This was $18^{\circ}C$ higher than that of traditional greenhouse. After 20 days of active composting, temperature of rhizosphere soil started to decrease and remained constant at $23^{\circ}C$ after 35 days. For the traditional greenhouse, the averaged temperature ranged at $14{\sim}15^{\circ}C$. This results showed that composting greenhouse had the greater effect on increasing the underground temperature. Average value of evoluted $CO_2$ from the composting greenhouse for 70 days was $782{\sim}1154ppm$. This was $1.7{\sim}2.6$ times higher than that of the traditional greenhouse with an average of $440{\sim}462ppm$. $NH_3$ release was highest during $2{\sim}10$ days in intermittent aerated composting and reached to 134 ppm maximum on the 5th day, then decreased rapidly, and maintained at $3{\sim}4ppm$ after 17 days. Increased photosynthesis due to the $CO_2$ gas and a favorable rhizosphere environment due to the increased underground temperature resulted in improved growth, yield, and Brix degree of tomato fruit.

• Journal of Life Science
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• v.27 no.4
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• pp.390-397
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• 2017

Iron (Fe) is an important micronutrient for the health and growth of plants. Iron is usually provided by fertilizers, and iron-chelate fertilizers are well absorbed by plants. This study presents the plant growth-promoting effects of a new functional iron fertilizer, Fe-chelating crab shell powder (FCSP), which is generated from the chelation of Fe ions with crab shell powder. Iron chelate was derived from spent pickling liquor, which is rich in reductive iron, iron(II) oxide. To analyze the effects of FCSP on plant growth, we treated lettuce with several concentrations of FCSP in both lab- and field-scale experiments. In the lab-scale test, the treatment of 50 ppm of FCSP highly promoted growth and resulted in increases in the size, weight, number and chlorophylls content of leaves of plants compared to the treatment of crab shell powder. Fifty ppm of FCSP also increased the size and weight of leaves up to 2 times compared to the application of chemical fertilizer and/or compost in field conditions. In addition, the FCSP treatment resulted in the highest ion uptake of Fe in lettuce leaves. Moreover, FCSP led to increases in the amounts of Fe, Ca, available phosphorus and organic matter in treated soil, indicating that soil quality was improved. Taken together, our results demonstrate that FCSP promotes lettuce growth via enhancement of Fe availability and improves soil quality. Therefore, FCSP can be utilized as a new functional iron fertilizer.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.2
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• pp.151-157
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• 1998

Fly ash application with a rate of 0, 50, 100, $150Mg\;ha^{-1}$ in clay loam paddy, which had properties of pH 5.3 and low contents of silicate and boron, gave a strongly positive effects on the growth and yields of malting barley showing better responses in bituminous coal fly ash(BCFA) than anthracite fly ash(AFA). Especially, soil chemical characteristics improved greatly by fly ash were pH, available phosphate, exchangeable calcium, available silicate, and boron. Shoot length and the number of tiller till defrosting season appeared the most positive responses by application of BCFA $50Mg\;ha^{-1}$ and AFA $100Mg\;ha^{-1}$. However, the number of spikelet per panicle at heading stage was proportionally increased to the rates of each fly ash. As a result, the grain yields of malting barley were increased to $13.8(4.221Mg\;ha^{-1}){\sim}37.7%(5.106Mg\;ha^{-1})$ by application of BCFA and to $1.1(3.75Mg\;ha^{-1})-20.6%(4.473Mg\;ha^{-1})$ by application of AFA. Protein contents in the grain was the highest in $150Mg\;ha^{-1}$ plot, showing 10.5 and 10.8% by BCFA and AFA application, which were suitable for malting. At harvesting, plants showed 49 and 58% of lodging indices by application of BCFA 100 and $150Mg\;ha^{-1}$, respectively, which were equivalent to two fold values of those by AFA.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.477-488
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• 2020

Recently, foodborne illness outbreaks linked to fresh produce are being increasingly reported in the United States, the EU, and Korea as well. Some of this increase may be due to improved surveillance, increase in consumption, change in consumers' habits, and complex distribution systems. Garlic chive is a green, fresh-cut vegetable consumed year-round as a nutrition-rich herb in Korea. It is also prone to contamination with foodborne pathogens during pre-harvest, as amendment with high amounts of livestock manure or compost to soil is required in its cultivation. Our aim in this study was to evaluate microbial contamination of garlic chives, garlic chives cultivation soil, compost, and irrigation water in the southern part of Korea. Samples were collected in A, B, and C regions in 2019 and 2020, and 69, 72, 27, and 40 of garlic chives, soil, compost, and irrigated water, respectively, were analyzed for the presence of sanitary indicator bacteria (total aerobic bacteria, coliforms and Escherichia coli), Bacillus cereus, Staphylococcus aureus, pathogenic E. coli, E. coli O157:H7, Listeria monocytogenes, and Salmonella spp. In A, B, and C regions, levels of total aerobic bacteria, coliform, B. cereus, and S. aureus on all samples were between 1.14 and 8.83 log CFU/g, 0.43 and 5.01 log CFU/g, 0.41 and 5.55 log CFU/g, and 1.81 and 6.27 log CFU/g, respectively. B. cereus isolated from garlic chives and environmental samples showed β-hemolysis activity. Incidence of S. aureus in garlic chive and its production environments in 2020 was different from 2019. In this study, B. cereus and S. aureus were the only pathogenic microorganisms detected in all samples. As a result, this work suggests that continuous monitoring in the production and pre-harvest environment is required to improve hthe hygiene and safety of garlic chive.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.353-362
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• 2010

The contents of functional and nutritional components of 13 cultivars of Chinese cabbage (CC, $Brassica$ $rapa$ subspecies $campestris$) were analyzed to compare the effects of soil pH of the greenhouse (pH 6.2) and outdoor (pH 7.6). The CC cultivated on pH 6.2 (CC-6.2) soil contained significantly increased amounts (2-9 fold) of pectin, crude protein, vitamin C and vitamin E compared to the counterpart (CC-7.6). The contents of ash and the minerals (Ca, Fe, Na, and Mn) were also significantly increased in CC-6.2. However, CC-6.2 contained 40-50% lower contents of reducing sugars, cellulose and crude fat than CC-7.6. CC-7.6 contained more glucosinolates, gluconasturtiin (18.33 vs. $1.16nmol{\cdot}g^{-1}$ wet weight) and gluconapin (145 vs. $2nmol{\cdot}g^{-1}$ wet wt), than CC-6.2. In conclusion, CC-6.2 had an improved texture (high pectin and low cellulose) and nutritional value (high in protein, Ca, Fe, vitamin C, and E), whereas the CC-7.6 had better taste (high in reducing sugars) and anticancer functionality (high in glucosinolates).