• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.3
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• pp.113-121
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• 1994

Since it is difficult to expect the normal production of plants in greenhouses during hot summer season in Korea, certain provisions on the control of extreme environmental factors in summer should be considered for the year-round cultivation in greenhouses. This study was carried out to find a method to suppress the temperature rising of nutrient solution by cooling, which is able to contribute to the improvement of the plant growth environment in hydroponic greenhouse during hot summer season. A mechanical cooling system using the counter flow type with double pipe was developed for cooling the nutrient solution efficiently. Also the heat transfer characteristics of the system was analysed experimentally and theoretically, and compared with the existing cooling systems of nutrient solution. The cooling capacities of three different Systems, which used polyethylene tube in solution tank, stainless tube in solution tank, and the counter flow type with double pipe, were evaluated. The performance of each cooling system was about 41 %, 70% and 81 % of design cooling load in hydroponic greenhouse of 1 ,000m$^2$ on the conditions that the flow rate of ground water was 2m$^3$/hr and the temperature difference between two liquids was 10 ˚C According to the results analysed as above, the cooling system was found to have a satisfactory cooling capability for regions where ground water supply is available. Fer the other regions where ground water supply is restricted, more efficient cooling System should be developed.

• Journal of Plant Biology
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• v.7 no.2
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• pp.1-8
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• 1964

Cha, Jong Whan (Dept. of Biology, Graduate School, Dong Kuk Univ.) The changes of chemical properties of forest soils in dry and wet seasons. Kor. Jour. Bot. VII(2): 1-8, 1964. Soil selected for the present investigation was collected from a mountain of the Forestry Experiment Station of the vicinity of Seoul. The forest communities studied were three forest and a unplanted soils. The soil samples were obtained from each forest type during dry and wet seasons. And these samples were collected from four horizons of all communities respectively. It was showed that exchangeable hydrogen was increased by rainfall, and total exchangeable base decreased in the same way. The content of nitrogen is washed away by rainfall, especially ammonium nitrogen was highly significant between dry and wet season. On the contrary, organic matter and available phosphorus were of no significant difference between dry and wet seasons. The values of pH appeared a different response in dry and wet seasons according to the plant communities. The needle-leaved forest soils showed more acidity than the broad-leaved forest soils, and the least acidity in open places. All nutrients in soil studied gradually decreased down the profiles. According to statistical analyses of the soil components among all soil horizons, total exchangeable bases in wet season indicated only significant at 1%. Exchangeable hydrogen and organic matter of the soil in dry season was particularly very low with increased depth in the profile. The fertility level of most forested soils selected for the present investigation is low according to chemical tests for available nutrient elements.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.11
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• pp.1569-1574
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• 2005

The in situ nylon bag degradation and in vitro intestinal digestibility of dry matter (DM), and crude protein (CP) of mulberry (Morus alba) plant fractions was studied at four harvest stages, 3 (W3), 5 (W5), 7 (W7) and 9 (W9) weeks. Degradability of DM and CP of the whole plant and stem fractions declined significantly (p<0.01) with advancing plant maturity in the order W3>W5 and W7>W9 and W3>W5>W7>W9, respectively. The degradation of DM and CP of the leaf fraction was also influenced by plant maturity but no trend was observed. The degradation of DM and CP of the whole plant and leaves increased rapidly during the first 48 and 24 h of incubation, respectively, when maximum degradation was reached. In vitro intestinal digestibility of CP was more influenced by the residence time in the rumen than by plant maturity. This study showed that mulberry is suitable as a supplement, particularly to low-quality roughages, in providing a source of rapidly available nitrogen to the rumen microbes, hence improving the roughage degradability and intake.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.4
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• pp.215-218
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• 1982

The fertilizer efficiency of the compound fertilizers with different NPK Compositions were compared with that of simple fertilizers in the view of the yield differences of Jungweon Cheongyong Capsicum grossum of Hot pepper. The results were summarized as follows: 1. The yields of ripened red peppers of the compound fertilizer plot were higher than that of the simple fertilizer plot showing no statistical differences between the fertilizers. 2. No differences in the nutrient composition of the plant leaves were found between the treatments, thus the yield was not correlated with the nutrient composition. 3. In the soil where the compound fertilizers were used, the available phosphate content after the harvest increased but other nutrient contents were unchanged.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.5
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• pp.466-472
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• 2016

The objectives of the study were to analyze the various nutrient contents of ready-to-use-supplemental-food (RUSF) developed with Eastern African ethnic plants and compare them with commercially available supplemental food (CASF) for infants. RUSF was made with three African plants, including Ficus sur, Amaranthus caudatus, and Prosopis juliflorafa and locally available food ingredients in DR Congo and Ethiopia and was cooked at $180^{\circ}C$ for 20 min in a conventional oven. Macronutrients were analyzed by the AOAC method. Contents of 17 amino acids were analysed with amino acid analyzer, and vitamin $B_1%$ niacin, vitamin $B_6$, and vitamin C were analyzed with HPLC. Isomers of vitamin E were analyzed by GC-FID. The price of RUSF was 0.133 USD per 100g. Contents of macronutrients were not significantly different between developed RUSF and CASF. Results of amino acid analysis showed that most amino acid contents were similar or higher in RUSF compared with CASF. However, glutamic acid and lysine contents were less in RUSF than in CASF. Vitamin E and vitamin $B_1$ contents were more than five times higher in RUSF (22.40, 6.26 mg/100 g, respectively) than in CASF (4.00, 0.80 mg/100 g, respectively). Niacin was about three times higher while vitamin $B_6$ was almost 20 times higher in RUSF than in CASF. However, ascorbic acid was significantly lower in RUSF (3.43 mg/100 g) than in CASF (42.08 mg/100 g). Our study found that the developed localized RUSF showed higher nutrient contents in most micronutrients analyzed except for ascorbic acid. Out of 17 amino acids, glutamic acid and lysine contents in RUSF were less than in CASF. Therefore, further study is needed in order to improve these nutrients contents.

• Journal of Plant Biology
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• v.6 no.3
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• pp.1-5
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• 1963

Determination of the chemical properties in some forest soils and the naked soil developed on granite in the mountains of the vicinity of Seoul, Korea are presented in this study. The soil under the broad leaved forests has a higher nutrient indicated by available nitrogen, nitrate nitrogen, and phosphorus contents, compared with that under the needle leved forests. On the contrary the content of organic matter and base exchange capacity in the needle forest soils is higher than in the broad leaved forest soils. The significant difference between two horizons of each soil appeared only to be in the content of the available phosphorus, and that of the needle and the broad leaved forest soils, and the naked soils was the nitrate nitrogen and organic matter content among the several chemical properties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.355-365
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• 2015

Environment-friendly growth enhancers for rice are being promoted to reverse the negative impact of intensive chemical-based and conventional rice farming on yield sustainability and environmental problems. Several rhizosphere microorganisms and pyroligneous acids (PA) had demonstrated beneficial influence on growth, yield and grain quality of rice. Since most of the previous study had evaluated the effect of PGPR and PA on paddy rice singly, the effect of combined application of these on the growth and yield of paddy rice and on some soil chemical properties were determined. A four factorial pot experiment was conducted to evaluate the effect of PGPR, PA in combination with fertilizers and on different soil types. There were 54 treatment combinations including the control with three replications under complete randomized design. Plant growth parameters were evaluated using standard procedures during tillering and heading stages. Rice yield and some soil chemical properties were determined at harvest. Results showed that inoculation of Bacillus licheniformis and Fusarium fujikuroi enhanced plant growth by increasing the plant height which could be ascribe to its ability to promote IAA and GA production in plants. Inoculation of Rhizobium phaseoli enhanced chlorophyll content indicative to its ability to improve the N nutrition. However, these plant growth benefits during the vegetative stage were override by the fertilizer application effect especially during the maturity stage and grain yield. High fertilization rates on coarse-textured soil without nutrient loss resulted to high available nutrients and consequently high yield. Wood vinegar application however improved nutrient availability in soil which could be beneficial for improving soil quality. Further evaluation is necessary to fully assess the potential benefits that could be derived from inoculation of these organisms and wood vinegar application in different soil environment especially under different field conditions.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.6
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• pp.682-688
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• 2016

Food waste has recognized one of useful sources for potentially agricultural application to supply organic matter and nutrients in arable soil. However, there was little information on application of food waste compost related to the maturity and NaCl content in arable soil. This study evaluated the effect of food waste compost application on yield and fertility in soil under flooding and upland condition. The yields in rice and pepper cultivation decreased with increasing the rate of food waste compost application in soil (p<0.05). Maximum yields of rice ($49.0g\;plant^{-1}$) and pepper ($204g\;plant^{-1}$) were shown at 10 and $30Mg\;ha^{-1}$ of food waste compost application, respectively. The N, P, and K contents in grain and plant residues increased by the application of food waste compost, there was no difference on Na/K ratio in plant tissue among the treatments. Application of food waste compost resulted in the increase of pH, EC, TC, available P contents in soil after crop harvest, especially, which was shown the increase of the CEC and exchangeable sodium percentage (ESP) contents in irrespective of water condition. In conclusion, application of food waste compost in soil was effective on the supply of the organic matter and nutrient. However, it might need caution to apply food waste compost for sustainable productivity in arable soil because of potential Na accumulation.

• Korean Journal of Organic Agriculture
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• v.27 no.3
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• pp.341-351
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• 2019

Gynura procumbens (Family Asteraceae) is a medicinal plant commonly found in tropical Asia countries such as China, Thailand, Indonesia, Malaysia, and Vietnam. Traditionally, it is widely used in many different countries for the treatment of a wide variety of health ailments such as kidney discomfort, rheumatism, diabetes mellitus, constipation, and hypertension. The objective of this study was to select the natural growth media for hydroponic cultivation of Gynura procumbens. The commercially available thirty four different organic nutrient solutions were analyzed for growing Gynura procumbens. After analysis, two organic nutrient solution were selected, mixed (pH 5.5~6.5 / EC 0.5~1.0 ds/m) and then used as organic fertilizers. Thirty day old seedlings were planted and the environmental conditions of the rhizosphere were also examined to select the natural media composition. The minimum temperature of rhizosphere by type of natural media was highest in cocopeat media and lowest in perlite media. Furthermore, plant growth was examined from 50 days old seedlings, and vermiculite was observed to be most effective and perlite was the least effective component as natural media. The total polyphenol content of the studied plant material was also higher in vermiculite in comparison to other growth media. The Gynura procumbens yields were also higher in vermiculite in comparison to other growth media. Thus, vermiculite can be used to improve Gynura procumbens plant growth as a natural growth media.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1022-1022
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• 2001

To obtain accurate and repeatable analyses using NIR technology it is important to select an NIR instrument and / or its sample presentation attachments which allow the operator to minimize sampling errors without compromising the benefits of NIR analysis -namely rapid, low cost, minimal sample preparation, minimal structural facilities, minimal hazards. For each sample type and consistency there may be different optimal combinations of instrument, sample presentation attachment, and sample preparation. This paper will consider options available to NIR users in the area of plant and soil analysis and evaluate the potential benefits and disadvantages of crop nutrient diagnoses using laboratory based and airborne imaging techniques.