• Korean Journal of Environmental Agriculture
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• v.27 no.1
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• pp.10-17
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• 2008

The objective of this study was to estimate the pollutant loads from paddy fields by cultivation practices using a non-point-sources models. One of them is CREAMS-PADDY model that was developed considering the water balance and mass balance of paddy fields. The CREAMS-PADDY model was applied to provide basic data to reduce runoff loadings under various scenarios such as various water management control and various fertilizer condition. The model was verified against T-N, T-P and runoff flow data collected during cropping periods at 2000. The model results agreed well with the measured data in verification. The results showed that the model could be used for estimating the runoff loadings from irrigated paddy fields by cultivation practices was possible. Comparison of simulated the standard height and the sluice management of T-N and T-P runoff loadings from paddy fields were +32.4%, +10.3% in 10 mm below the standard height, -29.2%, -35.9% in 20 mm above the standard height, 52.6%, 59.0% in 40 mm above the standard height, respectively. Comparison of simulated the standard fertilizer and the fertilizer control of T-N and T-P runoff loadings from paddy fields were -1.3%, -21.7%in reduction of conventional fertilizer 30%, -1.0%, -12.5% in reduction of standard fertilizer 30%, respectively. Therefore, reducing nonpoint-sources nutrient loading by reducing fertilization may not work well in the range of normal paddy rice farming practices, and instead it could be achieved by reducing surface drainage outflow.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1011-1020
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• 2020

Efficient management systems of facilities make it possible to manage environmental conditions properly, such as the temperature, humidity and light source required for the best growth of the crops, as well as for the mass production of fruit and vegetables with high quality every year through an advanced and protected cultivation system. Powdery mildew is a type of chronic disease that is difficult to control during the production of Korean melons under a protected cultivation system, the use of which is increasing in production areas in Korea. Two Bacillus strains isolated from soil samples showed antagonistic activities against several pathogens, specifically Botrytis cinerea, Colletotrichum gloeosporioides, and Fusarium oxysporum f.sp. melonis; they were identified as Bacillus velezensis M2 and B. amyloliquefaciens M3 in a molecular biological test of the nucleotide sequences of gyrase subunit A (gyrA). The treatment was given three times at intervals of five days with 400-fold diluted cultures of B. velezensis M2 and B. amyloliquefaciens M3. This led to the inhibition of the incidence of powdery mildew disease in Korean melon leaves, which resulted in effective control efficiency against the incidence of powdery mildew disease with control values of 87% and 65%, respectively. Cultures of antagonistic microbes tested in this study can be used to increase the efficiency as part of an environmentally friendly management scheme to prevent powdery mildew disease during the protected cultivation of crops, including Korean melons.

• Journal of Soil and Groundwater Environment
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• v.29 no.1
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• pp.18-27
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• 2024

In this study, the pump and fertilize (PAF) was applied to reduce nitrogen infiltration into groundwater at three corn cultivation sites over a three-year period, and its effectiveness was evaluated. PAF involves pumping nitrate-contaminated groundwater and using it for irrigation, thereby replacing the need for chemical fertilizers. This method not only substitutes chemical fertilization, but also reduces nitrogen infiltration into groundwater through root zone consumption. To confirm PAF's effectiveness, an equal amount of nitrogen was applied in each cultivation plot, either through chemical fertilizer or irrigation with nitrate-contaminated groundwater. Regular monitoring of infiltrating pore water and groundwater was conducted in each cultivation plot. The linear regression slope for nitrate concentration in the pore water after repeated application of PAF ranged from -3.527 to -8.3485 mg-N/L/yr, confirming that PAF can reduce nitrate concentration in the pore water. With an increasing proportion of PAF, the infiltrating nitrate mass in pore water was reduced by 42% compared to plots fertilized with chemical fertilizer. Additionally, the linear regression slope of nitrate concentration in groundwater was calculated as -2.2999 and -9.2456 mg-N/L/yr. Therefore, continuous application of PAF in rural areas is expected to significantly contribute to reducing nitrate concentration in groundwater.

• Journal of Mushroom
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• v.13 no.2
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• pp.114-118
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• 2015

Mycoleptodonoides aitchisonii has been used a culinary material and traditional medicine for a long time in worldwide and recently the researches to find biological effects have been increased such as dopamine activation, preventive effect against phytopathogens, inhibitive effect against erythrocyte coagulation, anti-oxidative effect, anti-tumorigenic effect, etc. However it is hard to cultivate Mycoleptodonoides aitchisonii it is impossible to be mass-produced and in order to solve the problem in this study we found the appropriate cultivation period and the harvest point for it. For life cycle (from primordium formation to harvest) the morphology, weight, and quantity of polysaccharide of Mycoleptodonoides aitchisonii were measured using with 5 bodies per a day and it could be divided for 4 stages; primordium formation, growth, needle maturation, and aging. And then from the results the Zeide nonlinear growth curve could be gotten. At 13th day after cultivation there is the relation between the change of media weight and body weight and at 14th day after cultivation the rate of polysaccharide in the body was 11 %. However in the case of O2 insufficient supply the malformation of them was observed.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.131-137
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• 2006

This experiment was conducted to select prominent microorganisms with a good insecticidal activity among the ten species, which isolated from soil at the near of Chung-buk, Chung-nam, and Gang-won provinces and made protein crystal endotoxin. As a result, GB-413 strain was finally selected, which showed the high insecticidal activity against susceptible diamondback moth (Plutella xylostella), beet army worm (Spodoptera exigua) and tobacco cutworm (Spodoptera litura) as well as resistant diamondback moth strains. By modifying the cultivation process f.g. lowing the glucose concentration at early cultivation stage and adding the carbon after inducing the spores, the percentage of making spore as well as the number of active spore were increased and the time for cultivation and spore forming was reduced without a reduction of insecticidal activity. These results were not only applied successfully for the optimized cultivation process for a fermentation tank containing five tons capacity, but also improved the possibility of mass cultivation for commercial production.

• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.190-195
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• 2018

Sweetpotato [Ipomoea batatas (L.) Lam] represents an attractive starch crop that can be used to facilitate solving global food and environmental problems in the $21^{st}$ century. It can be used as industrial bioreactors to produce various high value-added materials, including bio-ethanol, functional feed, antioxidants, as well as food resources. The non-profit Center for Science in the Public Interest (CSPI) announced sweetpotato as one of the ten 'super foods' for better health, since it contains high levels of low molecular weight antioxidants such as vitamin-C, vitamin-E and carotenoids, as well as dietary fiber and potassium. The United States Department of Agriculture (USDA) also reported that sweetpotato is the best bioenergy crop among starch crops on marginal lands, that does not affect food security. The Food and Agriculture Organization (FAO) estimated that world population in 2050 will be 9.7 billion, and require approximately 1.7 times more food than today. In this respect, sweetpotato will be a solution to solving problems such as food, energy, health, and environment facing the globe in the $21^{st}$ century. In this paper, the current status of resources, and cultivation of sweetpotato in the world was first described. Development of a new northern route of the sweetpotato and its prior tasks of large scale cultivation of sweetpotato, were also described in terms of global food security, and production of high-value added biomaterials.

• Korean Journal of Organic Agriculture
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• v.27 no.1
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• pp.65-76
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• 2019

Bacillus genus are found abundantly in various sites and their secondary metabolites were used as potential agents in agriculture, notably plant growth promoting and bio-control. The objective of this study was to develop the culture conditions of GH1-13 strain including higher cell growth, stable endospore-forming and enhancement of potential agents which are related with plant growth promoting and phytopathogen suppression. The optimal carbon and nitrogen sources were determined by glucose and soy bean flour, respectively, then resulted in $7.5{\times}10^9cells/mL$, $6.8{\times}10^9\;endospore\;cells/mL$ and sporulation yield of 90% after 30 h cultivation in 500 L submerged fermenter at $37^{\circ}C$, pH 7.0. Cells and cell-free supernatant of GH1-13 strains showed the potent antifungal activity against phytopathogenic fungi of Colletotrichum gloeosporioides. It was also confirmed that indole-3-acetic acid (IAA) production of GH1-13 strain was greatly increased by addition of 0.3% tryptophan.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.383-391
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• 2021

To develop a cultivation method for the mass production of sweetpotato cultivars, 'Juhwangmi' (orange tuber) and 'Sinjami' (puple tuber), the yield of tuber roots and content of various functional substances were analyzed according to planting intervals and growing periods. For 'Juhwangmi, the total yield of tubers was increased by respectively 36% and 54% and the yield of tubers over 300 g was increased by respectively 170% and 221% in the 140-day and 160-day cultivation plots compared with that in the 120-day cultivation plot at the 70×20 cm planting interval. Similarly, the total content of beta-carotene in the tubers increased as the cultivation period was extended. In particular, beta-carotene content at the 70×20 cm planting interval was the highest. For 'Sinjami', at the same planting interval, the total yield of tubers and yield of tubers over 300 g significantly increased as the growing period was extended. Within the same cultivation period, the yield of tubers over 300 g and the total anthocyanin content of 'Sinjami' were higher at the 70×30 and 70×35 cm planting intervals than at the 70×20 and 70×25 cm planting intervals in the 140-day and 160-day cultivation plots. Moreover, the total polyphenol and flavonoid content was significantly higher in 'Sinjami' than in 'Juhwangmi', and the values were the highest in the 160-day cultivation plots. In particular, the content of these two functional substances in tubers over 300 g was the highest at the 70×30 and 70×35 cm planting intervals.

• Journal of Sericultural and Entomological Science
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• v.38 no.1
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• pp.31-35
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• 1996

To develope a solid culture media for the mass culture of Beauveria bassiana conida, wheat bran was selected as C source and N source. The pellet media were prepared without(P-I) and with(P-II) solidified ingredient. The moisture for the growth of B. bassiana was required over 4 : 2 of Media : D.W (W/V). The growth of Beauveria bassiana on the media type was more effective in media of pellet type than that of powder type. In addition, production of Beauveria bassiana conidia on the media size was more effective in media of S type($\Phi$3mm) than that of L type($\phi$7mm). And the yield of Beauveria bassiana conidia at 2$0^{\circ}C$ cultivation on 3 weeks post inoculation was similar to that of $25^{\circ}C$. Above-mentioned results showed that pellet medium (P-I) was effective to growth of Beauveria, suggesting that the pellet media may be useful in the mass production of Beauveria bassiana conidia.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.379-386
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• 2021

This study was undertaken to develop a cascade-type continuous culture system (CCCS) that combines both ICT and biotechnology (BT), for the mass production of microalgae. This system is capable of maintaining the essential culture conditions of pH, temperature, carbon dioxide, and illuminance control, which are key parameters for the growth of microalgae, and is economical for producing microalgae regardless of the season or location. It has the added advantage of providing stable and high productivity. In the current study, this system was applied to culture microalgae for 71 days, with subsequent analysis of the experimental data. The initial O.D. of the culture measured from incubator 1 was 0.006. On the 71st day of culture, the O.D.s obtained were 0.399 (incubator 1), 0.961 (incubator 2), 0.795 (incubator 3), and 0.438 (incubator 4), thereby confirming the establishment of continuous culture. Thus, we present a smart-farm based on ISMC (in-situ monitoring and control) for a mass culture method. We believe that this developed technology is suitable for commercialization, and has the potential to be applied to hydroponics-based cultivation of microalgae and cultivation of high-value-added medicinal plants as well as other plants used in functional foods, cosmetics, and medical materials.