• Title/Summary/Keyword: Planting Density

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The Limiting Current Density and the Regeneration of a Heterogeneous Ion Exchange Membrane in a Nickel Plating Rinse Waters Treatment Process by Electrodialysis (전기투석에 의한 니켈도금 폐수처리 공정에서 한계전류밀도와 불균질 이온교환막의 재생)

  • 윤용수
    • Journal of environmental and Sanitary engineering
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    • v.16 no.2
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    • pp.38-46
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    • 2001
  • In this work, the heterogeneous ion exchange membrane was used in a electrodialysis apparatus to treat a Ni planting rinse water because the heterogeneous ion exchange membrane was excellent efficiency as compared with low manufacturing cost, was easy to make, and had a good mechanical properties. For a regeneration of membrane and to obtain the optimal condition for a scale-up of apparatus after treating Ni plating rinse water, we would find about the limiting current density and the concentration polarization. When the Ni plating rinse water 150mg/L was treated with the electrodialysis apparatus using the heterogeneous ion exchange membrane, the limiting current density was about $1.49{\;}mA/\textrm{cm}^2$. And the limiting current density increased with the flow rate and concentration of Ni plating rinse water. We recognized that the used membrane could be reused by periodic backwashing because efficiency was constant when the membrane was backwashed after treating wastewater.

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Effects of Foliar Application of Chitosan and Wood Extraction on Rooting and Tuber Formation of Plug Seedlings in Potatoes (Chitosan과 목초액 엽면살포에 의한 감자 플러그 삽목표의 발근 및 괴경형성효율)

  • 송창길;강태균
    • Korean Journal of Organic Agriculture
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    • v.8 no.1
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    • pp.89-99
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    • 1999
  • To do mass multiplication of plug seedlings in potatoes, apical stem cuttings originated from virus-free microtubers were cut to one-two internodes and transplanted into the plug-tray. After 10days, we applied Chitosan and Wood Extraction on rooting and tuber formation of plug seedlings. To improve field adaptability of plug seedlings, rooted cuttings with a height of 20cm after 20days of cutting were transplanted ito the fields, We applied 500~2000ppm Chitosan on growth characteristics and tuber formation of that. The above and underground growths, such as plant height and number of leaves were significantly more vigorous after treatment with 500~1,000ppm Chitosan and 2,000ppm Wood Extraction, the spray treatment was carried out five times at intervals of four days after ten days of transplanting. T-N, K, P, Mg and Na, were higher as the concentrations of chitosan and Wood Extraction were higher. The growth and tuber yield in plug seedlings planting plot and seed potatoes planting plot were effectively highter as foliar application of Chitosan(500~2,000ppm) was done after planting the plot. T-N content in leaves and tuber was higher as the concentration of Chitosan was high. A similar tendency was shown in K, P and Mg. In the small tuber(under 30g), the number of tubers and tuber yield were relatively increased in the seed potatoes planting plot, but the large tubers(over 80g) yield was higher in the plug seedlings planting plot, and in order to increase tuber yield in plug seedlings it was necessary to add plant density to the field.

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Physico-Chemical Properties of the Recycled Waste Soils from Construction Site as Planting Soil (건설폐토석의 식생용토로서의 이화학적 특성)

  • Kim, Won-Tae;Yoon, Yong-Han;Park, Bong-Ju
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.10 no.5
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    • pp.31-39
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    • 2007
  • This study was carried out to evaluation the recycled waste soils from construction site for planting soil. For this purpose, the concentrations of polluted materials and the physico-chemical properties were measured at recycled soil samples of an industrial waste treating company in the Metropolitan landfill area. The concentrations of polluted materials did not exceed to the standard critical levels of soil pollution in all analyzed items. The measures of the samples soil texture (loamy sand), bulk density (1.09~1.32g/$cm^3$), saturated hydraulic conductivity ($1.6{\times}10^{-3}{\sim}1.8{\times}10^{-3}$cm/sec), solid phase distribution (0.4~0.5$m^3/m^3$), porosity (0.5~0.6$m^3/m^3$), Ex. $K^+$ (1.0~1.2cmol/kg), Ex. $Mg^{2+}$ (0.2~0.6cmol/kg) were identified as not worse than those of conventional planting soil. But the sample soils have serious problems for planting soil such as high levels of pH (9.6~11.5), EC (0.78~1.84ds/m) and Ex. $Ca^{2+}$ (25.6~34.5cmol/kg), low level of organic matter (0.2~0.3%). It is required to improve pH, EC and Ex. $Ca^{2+}$ of sample soils. Consequently, the results suggested a high potential of recycling of the wastes soils for planting soil.

Growth, Yield, and Quality of Vegetable Soybean and Their Responses to Different Planting Dates (풋콩품종의 생육, 수량 및 외관품질 특성과 파종기의 영향)

  • Kim, Hong-Sig;Koh, Mun-Hwan;Kim, Seok-Dong;Hong, Eun-Hi
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.2
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    • pp.228-235
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    • 1995
  • This study was conducted to obtain the basic informations for developing new varieties and cultural techniques for vegetable soybean at the Crop Experiment Station, Rural Development Administration, Suwon, Korea in 1992. Two vegetable soybean varieties, 'Hwaeom-putkong' and 'Seokryangputkong', and the other 'Jangyeobkong' for soy-paste were planted at three planting dates(April 15, May 15, June 15). The characteristics of growth, yield, and quality were compared between vegetable and soy-paste soybean genotypes in response to different planting dates.Vegetable soybean varieties, 'Hwaeomputkong' and 'Seokryangputkong' were more resistant to lodging, earlier in maturity, higher in the density of pod set on stem and percentage of poded nodes, and larger in grain size than Jangyeobkong for soy-paste. Earlier planting (April 15) of vegetable soybean varieties increased the yield of green pod as well as improved quality in number of green pods per 500g and length and width of green pod.

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Induction of Systemic Resistance in Watermelon to Gummy Stem Rot by Plant Growth-Promoting Rhizobacteria

  • Lee, Yong-Hoon;Lee, Wang-Hyu;Shim, Hyeong-Kwon;Lee, Du-Ku
    • The Plant Pathology Journal
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    • v.16 no.6
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    • pp.312-317
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    • 2000
  • The selected five plant growth-promoting rhizobacteria (PGPR) strains, WR8-3 (Pseudomonas fluorescens), WR8-6 (P. putida), WR9-9 (P. fluorescens), WR9-11 (Pseudomonas sp.), and WR9-16 (P. putida) isolated in the rhizosphere of watermelon plants were tested on their growth promotion and control effect against gummy stem rot of watermelon. Strains, WR8-3 and WR9-16 significantly increased stem length of watermelon, and there was a little increase in leaf area, fresh weight and root length when strains, WR8-3, WR9-9 and WR9-16 were treated. Generally, seed treatment was better for plant growth promotion than the soil drench, but there was no significant difference. Seed treatment and soil drench of each bacterial strain also significantly reduced the mean lesion area (MLA) by gummy stem rot, but there was no significant difference between the two treatments. At initial inoculum densities of each strain ranging from 10$^6\;to\;10^{15}$ cfu/g seed, approximately the same level of disease resistance was induced. But resistance induction was not induced at the initial inoculum density of 10$^3$ cfu/g seed. Resistance was induced by treating the strains, WR9-9, WR9-11 and WR9-16, on all of four watermelon varieties tested, and there was no significant difference in the decrease of gummy stem rot among varieties. Populations of the strains treated initially at log 9-10 cfu/g seed, followed with a rapid decrease from planting day to 1 week after planting, but the population density was maintained above log 5.0 cfu/g soil until 4 weeks after planting. Generally no or very weak in vitro antagonism was observed at the strains treated excepting WR9-11. Rifampicin-resistant bacteria which had been inoculated were not detected in the stems or leaves, which suggesting that the bacterium and the pathogens remained spatially separated during the experiment. This is the first report of rsistance induction in watermelon to gummy stem rot by PGPR strains.

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Effects of Nitrogen Level and Planting Density on Chemical Properties in Korean Native Tabacco Varieties (재래종연초의 화학특성에 미치는 질소시비량 및 재식밀도의 영향)

  • 정형진;김길웅;박수준
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.34 no.3
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    • pp.288-295
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    • 1989
  • This study was conducted to establish the most appropriate nitrogen levels and planting densities which can attribute to increase of aromatic substances in tobacco variety, Hyangcho, maintaining its original aroma. An increase of nitrogen fertilization from 3 to 12 kg per 10a increased total alkaloid content 2.0% to 3.3%, while an increased nitrogen fertilization decreased the contents of total sugar, starch, fatty acid etc., Which seem to be the positive components relating to tobacco aroma the contents of alkaloids were decreased and total fatty acids were increased as the planting densities increased. The higher contents of 2. 3-methylbutanoic and 3-methylpentanoic acid was obtained at the density of 3 plant per pit (12,498 plant/10a). The components determined in the neutural fraction such as solanone, furfural, furfurylalcohol and benzyl alcohol were presented in higher amount at the higher densities. The volatile acids such as 2. 3-methylbutanoic acid 3-methylpentanoic acid decreased and also the contents of butanol, furfutal, furfuryl alcohol, hexanol, cinnamil, acetophenone, benzyl acetate and solanone etc., were decreased as the nitrogen level increased from 3 to 12 kg per l0a.

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Comparison of Growth Characteristics Between Natural and Plantation Stand on Acer okamotoanum (자생지와 조림지에서의 우산고로쇠나무 생장특성 비교)

  • Yoon, Jun-Hyuck;Kwon, Su-Duk;Jeon, Kwon-Seok;Kang, Jeong-Hee;Cho, Min-Gi;Moon, Hyun-Shik
    • Journal of agriculture & life science
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    • v.46 no.1
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    • pp.83-90
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    • 2012
  • This study was undertaken to analyze 1) the growth characteristics for the optimal planting density and 2) reached ages of sap tapping for the planting timing of Acer okamotoanum in natural and plantation stand. Soil in natural stand was significantly more fertile than that of plantation stand. Early growth of A. okamotoanum in plantation stand was affected by planting density. Results showed that there was a positive relationship between the DBH and crown width in both natural and plantation stands. Reached ages by DBH were no significant difference in natural stands. Reached ages on DBH 10 cm were approximately 19 and 9 in natural and plantation stands, respectively.