• Korean Journal of Weed Science
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• v.14 no.1
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• pp.23-27
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• 1994

Nutrient culture study was initiated to examine the selectivity of dithiopyr(S, S-dimethyl 2-difluoromethyl)-4-(2-methylpropyl)-6-(trifluoro methyl)-3, 5-pyridine dicarbothiate) in rice(Oryza sativa L.) and barnyardgrass(Echinochloa crusgalli Beauv.). Absorption and translocation of $^{14}C$-dithiopyr in rice and barnyardgrass were also investigated to determine their selective mechanism. Rice was very tolerant, but barnyardgrass was susceptible to dithiopyr. The absorption of dithiopyr was greater in barnyardgrass than in rice and most of them remained in the roots of both species. Dithiopyr was absorbed by roots and basal shoots of both species. Translocation of dithiopyr was very low but was higher in barnyardgrass than in rice. Therefore, this study suggest that the selectivity of dithiopyr between rice and barnyardgrass may be mainly attributed to the absorption and translocation of dithiopyr in plants.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.3
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• pp.232-240
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• 2019

Approximately 80% of the world's sea cucumbers Apostichopus japonicas are processed into dried sea cucumbers. The hot air-drying method is currently used in industry, but it has many problems, such as a short drying time, severe browning, high nutrition loss, and low recovery. In this study, the moisture absorption rate, dry recovery rate, and lipid nutrient composition of sea cucumber dried by heat pump decompression and with a hybrid dryer were investigated. The moisture absorption rates for hybrid-dried sea cucumbers at 24, 48, 72, 96, and 120 h were 241.3%, 427.7%, 652.0%, 721.0%, and 742.2%, respectively. The moisture absorption rates for hot air-dried sea cucumbers were 155.8%, 240.0%, 390.3%, 655.5%, and 667.4%, respectively. Thus, moisture absorption was faster and greater with hybrid drying than with hot air drying. The dry recovery rate at 24 h was greater for hybrid-dried sea cucumber (70.7%) than for hot air-dried sea cucumber (59.8%). Saturated fatty acid contents of the hybrid- and hot air-dried sea cucumbers were 30.0% and 37.5%, respectively. Moreover, greater ${\Sigma}n-3$ polyunsaturated fatty acid content was found in hybrid-dried sea cucumber (15.8%) than in hot air-dried sea cucumber (11.7%).

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.1
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• pp.48-53
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• 2005

Finger millet straw and rice straw are the major source of dry roughage in southern India. They distinctly vary in their morphological and nutritional characters. Hence an effort was made to study the nutrient utilization, milk yield and composition in crossbred dairy cows fed either finger millet (group 1) or rice straw (group 2) as a source of dry roughage. The cows in both the groups were fed as per requirement with concentrate, green fodder and straw in the ratio of 30:45:25 parts (DM). At the end of 50 days of preliminary feeding a digestibility trial was conducted for 7 days and pooled samples of feed, fodder, feces, urine and milk were analysed for macro and micro nutrient content. Finger millet straw contained more CP, Ca, P, Mg, Cu, Zn and Co than rice straw and rice straw contained higher ADF, ash and silica. The intake of DM, CP, EE, NDF, ADF and most micronutrients (Ca, P, Mg, Cu, Zn, Fe, Mn and Co) was significantly higher in cows fed finger millet straw. The digestibility of DM, CP, NDF and ADF was significantly higher in cows fed finger millet straw and the gut absorption of Ca, Cu, Mn and Co was significantly higher in cows fed finger millet straw. The dietary requirement of all micronutrients in both the group of cows could be met irrespective of the type of roughage fed except that of Ca, which was low (0.61 and 0.40%) in rice straw fed cows. The average daily milk yield (L/cow) was also higher (7.0 L) in cows fed finger millet straw as compared to cows fed rice straw (6.3 L). The average milk composition also did not differ except that of milk fat which was significantly (4.7 and 4.5%) low in cows fed rice straw. The overall results of this study have indicated that finger millet straw is a better source of dry fodder than rice straw and while feeding rice straw as the sole roughage to dairy cows there is need to supplement additional calcium as this could be one of the limiting nutrients for milk production.

• Journal of Bio-Environment Control
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• v.8 no.2
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• pp.115-124
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• 1999

This study was conducted to determine the optimum root zone environment condition and proper nutrient management system for lettuce in hydroponics. For the root zone environment condition, several level of pH and electrical conductivity (EC) were treated respectively. Though all the level of pH 4 to pH 8, except pH 3, performed better growth without any visible physiological disorder, the optimum pH of the nutrient solution for lettuce production was pH 5.5 to 6.0. The optimum ionic strength of the solution was EC 1.2 to 1.6 mS $cm^{-1}$ / because higher nutrient level caused tip burn symptom by calcium deficiency. Considering the above results, it is concluded that lettuce can be efficiently mass-produced through the optimum root zone environment.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.52-60
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• 2010

We investigated temporal changes of growth of hydrophytes, aquatic biota and absorption of nutrient depending on planting mat type (synthetic fiber, coconut fiber) of artificial vegetation island (AVI) through pilot test using AVI miniatures in Kyungan Stream area of Lake Paldang. There were not significant differences of the water quality parameters (DO, pH, conductivity, turbidity, temperature), phytoplankton and zooplankton abundance among AVI miniatures and control station. The benthic macroinvertebrates showed most individual numbers in the miniature which was made by synthetic fiber and planted with Phragmites australis. The average and maximum height of hydrophytes in AVI miniatures was similar except one miniature where Phragmites australis was planted in synthetic fiber mat and grew more slowly. The adsorbed amount of nutrients and microbes in coconut fiber mat were larger than those in synthetic fiber mat regardless of trophic state of installed waterbody. The continuous increase of adsorbed amount of nutrients and microbes of coconut fiber mat for 8 months in an oligotrophic lake indicates that coconut fiber mat is suitable for the planting mat of AVI in an oligotrophic lake where nutrients are limited for growth of hydrophytes.

• Journal of Nutrition and Health
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• v.55 no.4
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• pp.441-449
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• 2022

This review is focused on analyzing the limits and shortage of zinc (Zn) for the 2020 Dietary Reference Intakes for Koreans (KDRIs), and provides suggestions for the future establishment of the 2025 KDRIs for Zn. The 2020 KDRIs for Zn have been established to estimate the adequate requirement (EAR), recommended nutrient intakes (RNI), adequate intake (for only 0-5 mon) and tolerable upper intake level (UL). EAR was estimated in 2-stages: the first stage was to construct of the frame of analysis for Zn requirement and the second stage involved a factorial approach by considering the various factors which affect Zn requirement, such as intestinal and urine Zn loss, Zn requirement for growth and development, and Zn absorption rate. For a more precise and accurate establishment of the Zn requirement, we suggest for the following to be considered: 1) considering that Zn is present in minuscule amounts as a trace element in our body, the present values for Zn EAR (as 6-9 mg/d) should be expressed as a decimal point for more accurate DRIs; 2) the frame of analysis for Zn requirement has to be more specifically and should includes the factors which affect Zn requirement; 3) both, the factorial approach and extrapolation method need to be well reviewed and thoroughly understood for establishing precise Zn requirement; 4) currently, human clinical study and balance study (Zn intake, excretion and absorption rate) are limited and more human Zn subject studies are required. All these suggestions are provided to better establish the Zn requirement in the 2025 KDRIs.

• Journal of Animal Science and Technology
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• v.66 no.1
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• pp.103-114
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• 2024

This study was done to investigate the effects of the incorporation of Achyranthes japonica extracts (AJE) in diet on the production parameters of growing pigs. Exp 1: Total, 105 crossbred pigs (average body weight: 24.47 ± 2.46 kg) were used in a 6-week feeding trial. Pigs (seven replicates, five pigs per pen) were allotted randomly to three treatments. Dietary treatments: CON (basal diet); basal diet with 0.025% AJE, and basal diet + 0.050% AJE). Growth performance, nutrient digestibility, fecal microbial count, and fecal noxious gas were assessed in this study. Average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G:F) were not affected by the addition of up to 0.05% AJE. In the case of apparent total tract digestibility (ATTD), dry matter (DM), nitrogen (N), and digestible energy (DE) were not changed in 3rd and 6th weeks of the feeding trial through the addition of AJE up to 0.05% in the growing pig diet. In microbial count, Lactobacillus and Escherichia coli count at 3rd and 6th week was similar in all the treatment diets. The inclusion of AJE at levels up to 0.05% in growing pig diet had no effect on the production of NH3, H2S, acetic acid, and CO₂ in the feces. After ending the Exp 1, a total of nine pigs were divided into three treatment groups. Treatment diets were included, TRT1, basal diet + powder quercetin 30 g; TRT2, basal diet + powder quercetin 150 g; TRT3, basal diet + powder quercetin 300g. Rate of absorption in blood was increased with the higher dose of quercetin. The results suggested incorporation of AJE up to 0.05% has no significant effect on ADG, ADFI, and G:F, as well as DM, N, and DE digestibility, fecal microbial count, and fecal noxious gas emission in growing pigs, even though no negative effect was found.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.348-353
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• 2009

Organic materials reveal the remarkable absorption and high buffer capacity for nutrient. Hence, organic materials need some different nutrient management skill from inorganic one. The objective of this study was to evaluate the effect of EC level of nutrient solution on the yield and quality of cut rose grown in the mixed substrate of coir and perlite. 3 EC levels of nutrient solution was treated, which were 0.7, 1.0, 1.3 times of standard solution (Aichiken solution, Japan) for cut rose hydroponics. EC of the standard solution was changed by season following as 1.4 (Apr.~June), 1.0 (July~Aug.), 1.4 (Sep.~Oct.), and $1.6dS{\cdot}m^{-1}$ (Nov.~Mar.) subsequently. The supply of nutrient solution was controlled by the signal of water potential at -5kPa using frequency domain reflectometry (FDR) sensor. As the results, marketable yield was similar for all treatments until 3rd harvest, but was decreased in high EC level from 4th harvest to 7th harvest as final. 0.7 times of standard solution decreased the ratio of unmarketable rose having short stem below 70cm and increased the ratio of high quality rose having long stem above 91cm. The flower weight and stem diameter of cut rose was higher in the low EC treatment than the others.

• Journal of Bio-Environment Control
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• v.15 no.1
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• pp.69-77
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• 2006

The experiment was conducted to investigate the nutrition absorption pattern in the growth stage and develope the optimal nutrient solution hydroponically grown the cherry tomato 'Koko' in closed substrate culture system with the nutrient solution of National Horticultural Research Station in Japan into 1/2S, 1S, and 2S. When plant was grown in 1/2S, the growth and yield were high and the pH and EC in the root zone were stable. Suitable composition of nutrient solution for cherry tomato was $NO_3-N\;6.8,\;PO_4-P\;2.7,\;K 3.2,\;Ca\;3.6\;and\;Mg\;1.1\;me\;L^{-1}$ in the early growth stage, $NO_3-N\;7.3,\;PO_4-P\;2.2,\;K\;3.7,\;Ca\;3.6;and\;Mg\;1.1\;me\;L^{-1}$ in the late growth stage by calculating a rate of nutrient and water uptake. To estimate the suitability for the nutrient solution in a development of cherry tomato developed by Wongkwang university in Korea (WU), plant was grown in perlite substrate supplied with different solution and strengths(S) by research station for greenhouse vegetable and floriculture in the Netherlands (Proefstation voor tuinbouw onder glas th Mssldwijk; PTG) of 1/2S, 1S, and 2S, respectively. The growth was good at the PTG and WU 2S in the early stage and the PTG of 1S and WU of 1S and 2S in the late stage. The highest yield of cherry tomato obtained in the WU of 2S. pH and EC in root zone of WU of 2S were stable during the early and late growth stage. Therefore when cherry tomato plant was grown in WU of 2S of EC $1.6{\sim}2.0\;dS\;m^{-1}$in the nutrient solution, not only stable growth and yield but also fertilizer reduction can be obtained than that of PTG.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.3
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• pp.188-196
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• 2014

This study aimed to understand the nutrient absorption, usage and allocation of Carpinus cordata in different soil and light environments. Seasonal changes of foliar nitrogen, phosphorous, chlorophyll contents, leaf mass per area (LMA) and nutrient retranslocation rates were investigated for C. cordata saplings growing in a natural deciduous broadleaved forest and an Manchurian fir (Abies holophylla) plantation in Gwangneung, Kyunggido. The deciduous forest had lower leaf area, higher light penetration, and better soil fertility than the Manchurian fir forest. However, available soil phosphorous content in the deciduous forest was only one third of that in the Manchurian fir forest, which caused lower foliar phosphorous content and higher P retranslocation rate of C. cordata in the deciduous forest than that in the Mancurian fir forest. Soil nitrogen contents in the deciduous forest were higher than that in the Manchurian fir forest, however, no differences in foliar nitrogen content and retranslocation rate in C. cordata between the two stands were found. C. cordata in the Manchurian fir forest with high LAI throughout a year, had lower LMA, foliar nitrogen content and chlorophyll a/b, while had higher total chlorophyll content and chlorophyll/N than that in the deciduous forest. These results implied C. cordata under different environments are using different strategies for nutrient use and allocations.