• Journal of Biosystems Engineering
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• v.20 no.4
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• pp.390-396
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• 1995

This study was conducted to develop a computer simulation program for trickle application of nutrient solution. A computer simulation program using finite element method was developed to evaluate discharges of emitters on trickle application. The uniformity of application for two different lateral line lengths and three application methods was evaluated by the computer simulation program. The results of this study are as follows. 1. A computer simulation program was developed to determine emitter discharges from a trickle application system and pressures at emitter positions by finite element method and to design a uniform trickle application system. 2. The simulation program developed was verified by experiment. The root mean square error between experimental data and simulated data was 1.1% on the average discharge and it was found that the computer simulation program was an effective tool for the design of a trickle application system of nutrient solution. 3. The uniformity of trickle application system was evaluated for three different methods of supplying nutrient solution with different lateral line lengths. The best uniformity was obtained from the method, which supplies nutrient solution from both ends alternatively for the same period of time.

• Journal of Practical Agriculture & Fisheries Research
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• v.19 no.1
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• pp.5-14
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• 2017

This study was conducted to investigate the effects of nutrient solution strength on growth and nutrient element concentrations in leaf lettuce (Lactuca sativa L. cv. 'Dduksum') by hydroponic culture under fluorescent lamp and LED. Leaf lettuce were grown in closed hydroponic cultivation systems supplied with 1/2, 1 and 2 strength of nutrient solution recommended by horticultural experiment station in Japan. The growth of 'Dduksum' was highest in the 2 strength of standard nutrient solution. The amount of nutrient element in the recycled nutrient solution was higher at 2, 1 and 1/2 strength of nutrient solution. The concentration of NO₃-N, Ca²⁺, Mg²⁺ in the recycled nutrient solutions increased in 1 and 2 strength of nutrient solution but that of NH₄-N decreased gradually in 1/2 and 1 strength of nutrient solution. The concentration of K, Ca, Mg in leaf lettuce was maintained in the normal range, whereas the concentration of phosphorous was 1.3 to 1.6%, which was higher than proper range. As the concentration of NH₄-N decreases gradually in all the treatments, it is necessary to raise the rate of NH₄-N or add it.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.629-641
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• 2022

This research was conducted to secure fundamental data for development of a recirculating hydroponic system. To achieve this, Lycopersicum esculentum var. 'Dafnis' and 'TY Tiny' were grown with Yamazaki hydroponic solution and the inorganic element concentrations of plant leaves and nutrient solution of supplied and drained were analyzed periodically. The T-N and P contents in both varieties of tomato leaves showed gradual decreasing tendencies with the passage of time. The 'TY Tiny' tomato had higher contents of those two nutrients than 'Dafnis' tomato in the late stage. The K content of 'Dafnis' tomato was high in the early growth stage, but low in the late stage. However, that of 'TY Tiny' tomatoes rose in the late stage. The Ca content gradually increased in both varieties of tomato in the latter stages. The EC of the drained nutrient solution in both varieties of tomato showed increasing tendencies as time had passed, but the pH was get lowered in the drained solution. The concentrations of NO₃-N, K, Ca, Mg, Na, Fe, and B, except PO₄-P in the drained nutrient solution were generally higher than those in the supplied solution, especially in the period of October through December. The above results can be used for controlling of nutrient concentrations in the recirculated hydroponic cultivation of tomato.

• Journal of Wetlands Research
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• v.7 no.4
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• pp.33-42
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• 2005

Wetlands often function as a nutrient sink. It is well known that increased input of nutrient increases the primary productivity but it is not well understood what is the fate of produced biomass in wetland ecosystem. Water and sediment quality, decomposition rate of cellulose, and sediment accumulation rate in 11 montane marshes in northern Sierra Nevada, California were analyzed to trace the effect of nitrogen and phosphorus content in water on nutrient dynamics. Concentrations of ammonium, nitrate, soluble reactive phosphorus (SRP) in water were in the range of 27 to 607, 8 to 73, and 6 to 109 ppb, respectively. Concentrations of ammonium, calcium, magnesium, sodium, and potassium in water were the highest in Markleeville, which has been impacted by animal farming. Nitrate and SRP concentrations in water were the highest in Snow Creek, which has been impacted by human residence and a golf course. Cellulose decomposition rates ranged from 4 to 75 % per 90 days and the highest values were measured in Snow Creek. Concentrations of total carbon, nitrogen, and phosphorus in sediment ranged from 8.0 to 42.8, 0.5 to 3.0, and 0.076 to 0.162 %, respectively. Accumulation rates of carbon, nitrogen, and phosphorus fluctuated between 32.7 to 97.1, 2.4 to 9.0, and 0.08 to $1.14gm^{-2}yr{-1}$, respectively. Accumulation rates of carbon and nitrogen were highest in Markleeville and that of phosphorus was highest in Lake Van Norden. Correlation analysis showed that decay rate is correlated with ammonium, nitrate, and SRP in water. There was no correlation between element content in sediment and water quality. Nitrogen accumulation rate was correlated with ammonium in water. These results showed that element accumulation rates in montane wetland ecosystems are determined by decomposition rate rather than nutrient input. This study stresses a need for eco-physiological researches on the response of microbial community to increased nutrient input and environmental change because the microbial community is responsible for the decomposition process.

• Journal of the Korean Wood Science and Technology
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• v.23 no.4
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• pp.46-53
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• 1995

The anatomy of Korean diffuse-porous woods, 36 families, 75 genera, 145 species, 215 specimens was described and analyzed. Sixteen wood anatomical characters, habit and phenology factors were determined by simple correlation and principal component analysis. Strong positive correlations were found between vessel element length and fiber length, ray width and ray height, simple pits of fiber wall and paratracheal parenchyma distribution. The results of principal component analysis (PCA) disclose the primitive characteristics and the direction of xylem evolution of Korean diffuse-porous woods. The xylem evolution scenario for Korean dicotyledonous woods is considered to be developed in the direction of decreasing trends of vessel frequency, vessel element length, and length/diameter(L/D) ratio of vessel element but increasing trends of vessel diameter, fiber length/vessel element length(F/V) ratio, libriform wood fibers, simple perforation, and homogeneous ray composition. Increase of vessel diameter and decrease of vessel frequency seem to be related to the improvement of conductive efficiency, and increase of the vessel element length and occurrence of scalariform perforation in vessel element may be related to enhanced of conductive safety. Also the libriform wood fibers and ray features appear to have relationship with mechanical support and nutrient metabolism, respectively.

• Journal of Korean Society of Forest Science
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• v.96 no.2
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• pp.214-221
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• 2007

The effect of nutrient availability and forest type on the nutrient turnover of fine roots is important in terrestrial nutrient cycling, but it is poorly understood. I measured nutrient turnover of hardwoods and softwoods at three well studied sites in the northeastern US: Sleepers River, VT; Hubbard Brook, NH; Cone Pond, NH. Significant differences in nutrient turnover by fine roots were observed among sites, but not between forest types. The magnitude of differences for each element ranged from 3 times for P and N to 8 times for Ca and Mg between sites. Smaller differences of 0.2 to 0.8 times were observed between forest types. In hardwoods, the Sleepers River 'new' site had $23kg\;ha^{-1}\;yr^{-1}$ Ca, $7kg\;ha^{-1}\;yr^{-1}$ Mg, and $16kg\;ha^{-1}\;yr^{-1}$ K turnover, owing to high root nutrient contents and turnover. Cone Pond had the highest turnover for Mn ($0.8kg\;ha^{-1}\;yr^{-1}$) and Al ($16kg\;ha^{-1}\;yr^{-1}$), owing to high nutrient contents. The Hubbard Brook hardwood site exhibited the lowest turnover of these elements. In softwoods, the variation in turnover of Ca, Mg, and K was lower than in hardwoods. The Hubbard Brook had the highest turnover for P ($1.6kg\;ha^{-1}\;yr^{-1}$), N ($31kg\;ha^{-1}\;yr^{-1}$), Mn ($0.4kg\;ha^{-1}\;yr^{-1}$), Al ($10kg\;ha^{-1}\;yr^{-1}$), Fe ($6.4kg\;ha^{-1}\;yr^{-1}$), Zn ($0.3kg\;ha^{-1}\;yr^{-1}$), Cu ($34g\;ha^{-1}\;yr^{-1}$), and C ($1.1Mg\;ha^{-1}\;yr^{-1}$). Root Ca turnover exponentially increased as soil percentage Ca saturation increased because of greater root nutrient contents and more rapid turnover at the higher Ca sites. These results imply that nutrient inputs by root turnover significantly increase as soil Ca availability improves in temperate forest ecosystems.

• Mass Spectrometry Letters
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• v.11 no.4
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• pp.108-112
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• 2020

A certified reference material (CRM) for the analysis of nutrient elements in an edible mushroom (Ganoderma lyceum) powder has been developed (KRISS CRM 108-10-011). The mass fractions of calcium (Ca), iron (Fe), and zinc (Zn) were measured by isotope dilution inductively coupled plasma mass spectrometry (ID ICP/MS). To dissolve the fungi cell wall of mushroom consisted of chitin fibers, sample preparation method by single reaction chamber type microwave-assisted acid digestion with acid mixtures was optimized. The mean measurement results obtained from 12 sample bottles were used to assign as the certified values for the CRM and the between-bottle homogeneities were evaluated from the relative standard deviations. The certified values were metrologically traceable to the definition of the kilogram in the International System of Units (SI). This CRM is expected to be used for validation of analytical methods or quality control of measurement results in analytical laboratories when they determine the mass fractions of elements in mushroom or other similar samples.

• Journal of Bio-Environment Control
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• v.8 no.3
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• pp.183-191
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• 1999

In the recirculating hydroponics, pH of nutrient solution was gradually decreased until the middle of growing-period, and then began to go up and reached the initial level at the latter of growing-period regardless of Cu·Zn content. Changes of pH was gently down for supply of humus in nutrient solution. The growth of lettuce was good with supply of humus, but it was decreased as Cu·Zn content was increased. Although leaf chlorosis was caused by excessive content of Cu·Zn as 5, 10 ppm, it was controlled by adding humus in nutrient solution, and fresh weight of lettuce was obviously improved by adding humus.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.1-8
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• 1986

This study was investigated about influence of different cold water irrigation on the nutrient uptake of leaf blade, rachis branches and chaff. Longer duration of cold water irrigation increased total nitrogen content in leaf blade, branches and chaff but decreased the content of phosphate, potassium and silicate. The highest content of total nitrogen and phosphate showed at heading stage, that of potassium in leafblades and branches at heading but in chaff at maturing stage, and that of silicate at maturing stage. Inorganic element content in branches was similar with that in chaff in general. The excessive uptake of nitrogen by cold water irrigation caused decrease in the uptake phosphate, potassium and silicate showing clear nutrient disorder in the blades and chaff. High total nitrogen and low silicate in rice plants seemed to lead to degeneration of branches and spikelets, and to spikelet sterility. Degeneration and sterility appeared to be closely related to nutrient status of branches.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.252-260
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• 2008

This study was conducted to observe the characteristics of mineral nutrient uptake of single-node cutting rose 'Versilla' and to determine optimal nutrient solution control method for soilless culture of 'Versilla' in a closed hydroponic system. Nutrient solution was managed by five different control methods: macro- and micro-element control in aeroponic system (M&M), macroelement control in aeroponic system (M), nutrient solution supplement in aeroponic system (S); electrical conductivity (EC) control in aeroponic system(EC-A); EC control in deep flow technique system(EC-D). The concentration of $NO_3$-N exceeds optimal range whereas P and Mg decreased at the later stage of plant growth with the EC control method, EC-A and EC-D. The overall mineral nutrient content increased with S. On the other hand the nutrient content at the root environment was maintained optimal with M&M and M. The nutrient solution control methods had significantly effect on the cut-flower quality. In the M&M and M, flower length, fresh weight and root activity were higher than those with the other mineral nutrients control methods. The maximal efficiency of photochemistry (Fv/Fm) was higher for M&M, M and S than that with EC-A and EC-D. Based on the above results, it is highly recommended to control nutrient solution by mineral nutrient control methods (M&M and M) in a closed hydroponic system for single-node cutting rose, 'Versillia'.