• 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.

• 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'.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.10a
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• pp.88-91
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• 1998

최근 급속한 산업발달로 인하여 환경오염이 날로 심화되고 있으며, 특히 재배적인 측면에서 토양이나 수질의 중금속오염 문제가 크게 우려되고 있다. 이 중 Cu와 Zn은 식물체의 탄수화물이나 단백질 합성 및 여러 가지 효소 작용에 필수적인 원소이지만 그 양이 과다하면 철 결핍 증상과 비슷한 잎의 황화(chlorosis)현상을 일으킨다. 한편, humus내에 함유되어 있는 humic acid는 양액에 첨가하면 다가의 양이온과 결합하여 난용성 염을 형성하고 (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.497-498
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• 2001

해조는 생장을 위해 다양한 무기원소를 필요로 하며 (O'Kelley 1974), 특히 질소는 빈번하게 해조의 생장을 제한하는 가장 중요한 영양원의 하나로 알려져 있다(Topinka 1978). 이러 한 질소는 해중에서 여러 형태 (Amino acids, L - leucin, nitrite, nitrate, ammonium)로 해조류에 이용되는데, 이중에서도 nitrate는 연안에 비교적 우세하게 존재하며 (Wheeler and North, 1980), 해조류 조직내 전체 질소중 7-15％ 정도를 차지하고있다 (McGlathery et al. 1996). (중략)

• Journal of Bio-Environment Control
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• v.11 no.4
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• pp.168-174
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• 2002

A new circulating hydroponic system was invented for oriental melons grown in the greenhouse. For developing nutrient solution management techniques, we examined the changes of nutrient contents of circulating solution in three different types of new hydroponic systems. The yield and fruit quality of oriental melons in Hydroponics were better than those in soil culture. The substrate culture was appropriate fer hydroponics of oriental melons, and NFT was turned to be the opposite due to the physiological disorder during hot seasons. Yamazaki's melon solution with EC 2.0dS.m$^{[-10]}$ was the most appropriate for oriental melons. The new circulating hydroponic system seemed to be appropriate for oriental melons because of the stable EC, pH and the macro- and micro-element contents. NO$_3$-N, Ca and Mg contents in the circulating solution kept a good balance in all types of hydroponics. However, p content, compared to other types, decreased by the degree of 1 me.L$^{[-10]}$ in perlite medium. K content showed irregular status in perlite but showed the stable status in cocopeat. Generally, microelements, except Mo, showed stable absorption in the substrate culture. However, in NET, most of the elements showed irregular absorption except B and Mn. Microelement absorption, especially Cu, Zn and Mo, decreased during hot seasons.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.369-376
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• 2006

This research was conducted to evaluate the effect of root medium formulations on growth and nutrient uptake of hot pepper 'Knockgwang' in 72-cell plug trays. To achieve this, the nine root media were formulated by adjusting blending rate of perlite (PL) to coir (CO), peatmoss (PM) or coir+peatmoss (5:5, v/v, COPM). Then, the growth characteristics and tissue nutrient contents were determined at 35 and 70 days after sowing. The elevated blending rate of PL to CO increased fresh and dry weight of hot pepper at 35 days after sowing. The treatments of 20% in blending rate of PL to PM or that of 0% to COPM produced the highest fresh and dry weight among perlite treatments of PM or COPM. The results of crop growth at 70 days after sowing also showed similar trends to those of 35 days after sowing. The elevated blending rate of PL to CO or PM decreased tissue $P_2O_5$ and K contents and increased Ca and Mg contents at 35 days after sowing, With the equal blending rate of perlite, the plant tissue grown in CO had higher K contents and lower N, Ca and Mg contents than those in PM and COPM. The elevated blending rate of perlite in three organic matter also decreased tissue $P_2O_5$ and K contents at 70 days after sowing, but Ca and Mg contents were the highest in the treatment of 20% PL in CO, 40% PL in PM and 40% PL in COPM among perlite treatments in each organic matter.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.4
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• pp.225-232
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• 2003

Nutrients and water absorption by Citrus unshiu Marc. cv. Miyagawa Wase were examined using spray type of out-door hydroponics system. Three different concentration levels of nutrient solution were treated to citrus trees to examine nutrient uptake. To do so, concentration and the volume change of nutrient solution was measured for each treatment. By weighing the volume of solution and citrus trees, amounts of water uptake and fresh weight increase were observed periodically. Water uptake by trees increased as tree grew and time elapsed, but was lower at high level of nutrient concentration than the rest, due partly to the reduction in hydraulic conductance and to the sustained high salt concentration. Rapid increase in fresh weight and nutrient uptake occurred from May to July and from August to September. The amounts of nutrient uptake were significantly different among nutrient levels: the higher concentration, the greater uptake by citrus tree. The absorbed amounts of $NO_3$, K and Ca were much higher than those of $NH_4$, S, P, Mg, and Fe. Most mineral contents in leaves were proportional to the concentration of supplied nutrient solutions. From the results of nutrient absorption and contents in leaves at different levels of nutrient solutions, the composition of major elements for citrus nutrient solution can be modified as follows: 27.1, 16.5, 66.0, 80.0, and $24.0mg\;L^{-1}$ for N, P, K, Ca, and Mg, respectively.

• Journal of Bio-Environment Control
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• v.15 no.1
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• pp.8-20
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• 2006

This research was conducted to determine the plant growth and nutrient contents of potted chrysanthemum 'Lima Honey' as influenced by application rate of dolomite in three root media, peatmoss+vermiculite (1:1, v/v), peatmoss+composted rice hall (1:1, v/v), and peatmoss+composted pine bark (1:1, v/v). All root media contained polyacrylic acid sodium salt (PASS) at a rate of $4.5g L^{-1}$. In crop growth at 40 and 80 days after transplanting, elevated application rates of dolomite up to $6.0g L^{-1}$ in three root media increased fresh and dry weights per plant. But the treatment of $9.0g L^{-1}$ had less fresh and dry weights than those of $6.0g L^{-1}$. Tissue phosphorus content decreased and those of Ca and Mg increased by the elevated application rates of dolomite. Elevated application rates of dolomite in three root media resulted in the increase of pH, EC, and the concentrations of K, Ca, and Mg at 43 days after transplanting. Those at 80 days after transplanting were also increased, but the differences among treatments were less significant as compared to those at 43 days after transplanting. From the results of dry weight in potted chrysanthemum 'Lima Honey', the proper application rate of dolomite to three root media containing PASS at a rate of $4.5g L^{-1}$ were $6.0g L^{-1}$.

• Journal of Bio-Environment Control
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• v.15 no.1
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• pp.21-34
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• 2006

This research was conducted to determine the plant growth and nutrient contents of potted chrysanthemum 'Lima Honey' as influenced by application rate of fused superphosphate (FSSP) in three root media, peatmoss+vermiculite (1:1, v/v; PV), peatmoss+composted rice hall (1:1, v/v; PR), and peatmoss+composted pine bark (1:1, v/v; PB). All root media contained polyacrylic acid sodium salt at a rate of $4.5g L^{-1}$. The treatment of $1.4g L^{-1}$ in PV and those of $0.7g L^{-1}$ in PR and PB had the greatest fresh and dry weights in each root medium at both 43 and 80 days after transplanting. Elevated application rates of FSPP increased tissue contents of N, P, and K at both 43 and 80 days after transplanting in PV medium. However, the differences in tissue contents of N, P and K in PR medium were less significant among treatments of FSPP. The pre-planting FSPP also less affected the tissue contents of nutrients at 80 days after transplanting as compared to those at 43 days after transplanting. Elevated application rates of FSPP in PV medium increased EC and the concentrations of $NO_3,\;P_2O_5$, K, Ca, and Mg in soil solution of root media at 43 days after transplanting. The EC in PV medium at 80 days after transplanting was higher than that at 43 days after transplanting. The EC in all root media at 80 days after transplanting was not different among treatments of FSPP.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.6
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• pp.729-735
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• 1996

This study was carried out to investigate the effect of Germaniwn(Ge) treatment in the culture media on the Ge absorption by the callus induced from brown rice cv. Dongjinbyeo. MS medium was more effective on the growth ratio of callus and the content of Ge and some inorganic elements except K in callus than N$_{6}$ medium. The more Ge treatment in the N$_{6}$ or MS medium, the more Ge absorption by the callus, but the growth ratio of callus and the content of Ca, Mg, and K in callus were decreased. The content of Fe, Mn, Zn, and Cu was increased under treatment up to 100～200mg /$\ell$ Ge, but tended to be decreased under treatment more than that of Ge concentration. Under treatment less than 150mg /$\ell$ Ge, GeO$_2$(inorganic Ge) was more effective on the Ge absorption by callus than Ge-132(organic Ge), but Ge-132 was more effective on the Ge ab-sorption by callus and the activity of callus in case of treatment more than 150mg /$\ell$ Ge. The lower pH of culture medium, the higher Ge content in the callus. When callus was cultured on medium supplemented with Ge and 0.1～1.0mM of citric acid or myo-inositol, content of Ge and some inorganic elements in callus, as well as growth and dry weight of callus, were tend to increase in comparison to control, but myo-inositol was more effective on them than citric acid.cid.