• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.25-31
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• 1995

This study was carried out to investigate the effect of the concentration of nutrient solution on the growth of tomato(Lycopersicon esculentum Mill. cv. seokwang) in substrate culture. The substrates used in the experiment were perlite, vermiculite, and peatmoss. Tomato plants were treated with different concentrations of nutrient solution, viz. 0.5, 1.0, 2.0, 3.0, and 5.0mS/cm at seedling stage and transferred to different treatments, 1.0, 2.0, and 3.0mS/cm after transplanting in each substrate. As the concentrations of nutrient solution increased from 0.5 to 3.0mS/cm at seedling stage, the $CO_2$ assimilation rates of seedlings increased in all three substrate culture. Beyond this range, the $CO_2$ assimilation rates of seedlings decreased. By increasing the concentrations of nutrient solution, plant height, leaf length, leaf width, stem diameter, and top dry weight increased in perlite and were high at 2-5mS/cm in vermiculite. On the other hand, in peatmoss, the best result was shown at 3.0mS/cm. Therefore, the adequate concentration of nutrient solution on early growth of seedlings differed among substrates and was shown to be 3.0-5.0mS/cm in perlite, 2.0-5.0mS/cm in vermiculite, and 3.0mS/cm in peatmoss. Generally, as the concentrations of nutrient solution increased from 1.0 to 3.0mS/cm after transplanting, dry weight increased significantly in all three substrate culture. However, dry weights of tomato plants grown under high concentration of 5.0mS/cm slightly increased both at seedling stage and after transplanting.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.227-234
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• 2017

This study aimed to investigate the nutrient solution developed by based on nutrient-water absorption rate of strawberry 'Maehyang' by comparing growth and yield for 8 months with 5 kinds of nutrient solution with different ion composition. Strawberry plants were planted at elevated bed and supplied with five kinds of nutrient solutions (RDA), Yamazaki, PBG, University of Seoul (UOS) and NewUOS from one month onwards. Five types of nutrient solution were supplied to the strawberry plants associated with EC $1.0dS{\cdot}m^{-1}$, pH 6.0, $150{\sim}300mL{\cdot}plant^{-1}$ per day. At 60 days after planting, leaf width and leaf petiole of the strawberry plants showed significant differences among nutrient solution types and photosynthesis was higher in RDA and NewUOS nutrient solution and lower in PBG nutrient solution. The EC of the drainage on vegetative growth stage was $0.7{\sim}0.8dS{\cdot}m^{-1}$, which is lower than the supplied EC level, and to $1.0-1.2dS{\cdot}m^{-1}$, afterwards. The pH of the drainage was higher in Yamzaki solution as 6.2~6.8, while the pH of the UOS nutrient solution was lower in 5.1~5.2. Nitrate content was most absorbed in vegetative growth stage and after flower clusters development. The potassium uptake was highest at the NewUOS followed by UOS and Yamazaki nutrient solution. At six months after -planting fresh weight and dry weight of shoot and root were higher in UOS and NewUOS nutrient solution than other nutrient solutions, and the dry matter ratio was lower at 43.5% in Yamazaki nutrient solution and 30.6% in NewUOS nutrient solution than other solutions. Length, width, weight, and sugar content of the strawberries harvested from December to February were unaffected by treatment, but yield was higher in NewUOS nutrient solution due to increasing fruit number and average weight. From March to May, number of fruit was higher in Yamazaki nutrient solution. In conclusion, there was no difference in the growth of 'Maehyang' when 5 nutrient solutions were grown under hydroponics. But in order to improve the marketability, the NewUOS nutrient solution is appropriate to use from planting to February and it is suitable to use Yamazaki nutrient solution after March when temperature is high and the amount of fruit set per inflorescence.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.12
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• pp.1657-1662
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• 2004

The forage potential of mulberry (Morus alba) was evaluated under Malaysian conditions. The yield and nutrient composition of plant fractions of mulberry (whole plant, leaf and stem fractions) were determined at four harvest stages, namely, 3 (W3), 5 (W5), 7 (W7) and 9 (W9) weeks in a randomized block design. The study was conducted over a 9-month period to assess the persistence of the crop to repeated harvests. Fresh and dry matter (DM) yields of all plant fractions increased significantly (p<0.01) with increasing intervals between harvests, with highest DM yields at W9. The leaf to stem ratio declined significantly (p<0.01) from 5.2 (W3) to 0.9 (W9), indicating predominance of the stem fraction with advancing maturity. The nutritional composition of plant fractions was also significantly influenced (p<0.01) by advancing plant maturity at harvest. Crude protein (CP), ash and the metabolisable energy content of plant fractions declined significantly (p<0.01) from W3 to W9, while there was a corresponding significant increase (p<0.01) in the acid detergent fibre, neutral detergent fibre and acid detergent lignin. From this study it was concluded that the optimum stage to harvest the whole plant is 5 weeks, which is a compromise between yield, nutrient composition (CP and fibre components), and the annual number of cuts, with good crop persistence to repeated harvests. Fresh mulberry whole plant can provide a valuable supplemental source of nutrients to poor quality basal diets.

• Journal of Bio-Environment Control
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• v.20 no.1
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• pp.8-13
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• 2011

This research was carried out to investigate relationship between underground part environment control and growth or yield of sweet pepper in greenhouse as affected by covering materials. Daily amount of applied nutrient solution for research period in the greenhouse of plasticfilm house was more 1.6 times than that in glass house. But daily absorptance rate of nutrient solution and specific electrical conductance of rockwool between two greenhouses were not different in the range of 71.3-73.3% and $4.17{\sim}4.23dS{\cdot}m^{-1}$ respectively. Leaf area of sweet pepper, in leaf growth characteristics in two greenhouses, were $123.0cm^2$/leaf (in glass house) and $119.5cm^2$/leaf (in plasticfilm house), but the another (fresh and dry weight, dry matter) were not different. But weekly yield per square meter in glass house was more 1.3 times than that in plasticfilm house as $850g{\cdot}m^{-2}$ and $650g{\cdot}m^{-2}$, respectively. Effect of slab EC and absorptance rate of nutrient solution on leaf growth characteristics and yield between two greenhouses were not different. The results show when sweet pepper is cultured in greenhouse as affected by covering materials and above ground part environment, the plant growth and yield are little affected by underground part environment.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.365-371
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• 2007

Objective of this research was to investigate the effect of nitrogen concentrations in the fertilizer solution on growth and development of nutrient deficiency in leaf perilla (Perilla frutesens). The nutrient concentrations in above-ground plant tissue, petiole sap and soil solution of root media were also determined. Nitrogen deficiency resulted in dwarfed growth, small leaves, and bright yellow color of older leaves. The leaves of deficient plants became uniform yellowing in color and finally necrosis occurred on the deficient leaves. Elevation of N concentrations in the fertigation solution from 0 to 20 mM increased the crop growth in leaf length and width as well as fresh and dry weights of above ground plant tissue. That also resulted in the increase of chlorophyll contents. However, light toxicity symptoms such as abnormal leaf surface appeared on crops grown in 20 mM N fertilization. The plant growth was commercially acceptable in the treatments of 10 and 15 mM N. The plants with acceptable growth had 0.9 to 1.25% in N contents of above-ground plant tissue, 800 to $3,300mg{\cdot}kg^{-1}$ in the $NO_3-N$ concentrations of petiole sap, and 28.7 to $47.3mg{\cdot}kg^{-1}$ in the $NO_3-N$ concentrations of soil solution (1:2 extract) at 75 days after transplanting.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.537-545
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• 2012

Decay rate and nutrient dynamics during leaf litter decomposition of deciduous Quercus acutissima were compared between Gongju and Jinju for 33 months from December 2008 through March 2011. Percent remaining weight of Q. acutissima leaf litter after 33 months elapsed in Gongju and in Jinju was $41.2{\pm}0.4%$ and $28.3{\pm}0.6%$, and decay constant (k) was 0.39 and 0.61, respectively. Decomposition in Jinju was significantly faster than that in Gongju. This seemed to be related to higher temperature and precipitation in Jinju than those in Gongju during the experimental period. Initial C/N and C/P ratio of Q. acutissima leaf litter was 46.8 and 270.9, respectively. After 33 months elapsed, C/N and C/P ratios in Gongju decreased to 22.0 and 106.8, and those in Jinju decreased to 19.2 and 170.2, respectively. Initial concentration of N, P, K, Ca and Mg in Q. acutissima leaf litter was 8.31, 0.44, 4.18, 9.38, 1.37 mg/g, respectively. After 33 month elapsed, remaining N, P, K, Ca and Mg were 91.0, 85.4, 30.2, 47.9, 11.7% in Gongju, and 67.0, 54.2, 19.9, 30.0, 40.8% in Jinju, respectively. Except for Mg, remaining nutrients of decomposing leaf litter in Jinju were lower than those in Gongju. In case of N and P, initial immobilization was observed, however, only mineralization was observed in K, Ca and Mg during the whole experimental period.

• Journal of Bio-Environment Control
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• v.8 no.2
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• pp.108-114
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• 1999

This study was conducted to investigate the optimum environment for leaf lettuce (Lactuca sativa L. var. crispa) in a plant factory to increase mass-production efficiency of quality leaf lettuce. Transpiration rate and $CO_2$ assimilation rate were increased with increasing the photosynthetic photon flux density (PPFD). The highest fresh weight and dry weight were observed at the PPFD of 200 and 300 U moi $m^{-2}$ $s^{-l}$, respectively. The optimum aerial environment for the growth and quality of leaf lettuce in the plant factory was determined to be over 200 $\mu$mol $m^{-2}$ $s^{-1}$ for PPFB. Although the interaction between light intensity and nutrient level was not significant, the lettuce growth was the best under electrical conductivity (EC) of 1.8 mS $cm^{-1}$ / at high light intensity (250 $\mu$mol $m^{-2}$ $s^{-1}$ ) and EC of 2.4 mS cm-1 at low light level (150 $\mu$mol $m^{-2}$ $s^{-1}$ ) respectively.y.

• Korean Journal of Agricultural Science
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• v.43 no.2
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• pp.176-185
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• 2016

This research was conducted to evaluate various levels of dolomitic lime incorporated as pre-planting fertilizers on the growth of red-leaf lettuce. To achieve this, three root media were formulated by mixing coir dust with expanded rice hull (CD+ERH, 8:2, v/v), carbonized rice hull (CD+CRH, 6:4, v/v), and ground pine bark (CD+GRPB, 6:4, v/v). During formulation, equal amounts of essential nutrients, except dolomitic lime, were incorporated into all root media and the levels of dolomitic lime were varied from 0 to $7.5g\;L^{-1}$ at 1.5 g increments. Seedlings of red-leaf lettuces at the 3rd leaf stage were transplanted into each medium treatment. Crop growths were measured 5 weeks after transplant and soil solutions were collected every week and analyzed for pH, EC, and nutrient concentrations. The treatments showing the heaviest fresh and dry weights in CD+ERH, CD+CRH, and CD+GRPB were 4.5 g, 4.5 g, and $7.5g\;L^{-1}$ of dolomite, respectively. The pHs of three root media yielding the highest crop growths were in the ranges of 6.4 to 7.1. These ECs in CD+CRH medium were around $1.0dS\;m^{-1}$ higher than those of CD+ERH and CD+GRPB when application rates of dolomitic lime were equal. $K^+$ concentrations were higher than $Ca^{+2}$ and $Mg^{+2}$ concentrations until week 2 in three root media. But $Ca^{+2}$ and $Mg^{+2}$ concentrations were higher than $K^+$ concentrations after week 3 in all root media. The concentrations of $PO_4{^{-3}}$ in all root media got abruptly lower until week 2. These results indicate that appropriate levels of dolomitic lime, as pre-planting nutrient charge fertilizers in CD+ERH and CD+GRPB media, are 4.5 and $7.5g\;L^{-1}$, respectively.

• 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 Environmental Science International
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• v.26 no.1
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• pp.109-118
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• 2017

This study was conducted to investigate the effects of intermittent plasma and electrolysis treatments on lettuce (Lactuca sativa var. oak-leaf.), nutrient solution components ($NO_3{^-}-N$, $NH_4{^+}-N$, $PO{_4}^{3-}-P$, $K^+$, $Ca^{2+}$ and $Mg^{2+}$) and environmental parameters (electrical conductivity, total dissolved solids and pH). The recirculating hydroponic cultivation system consisted of planting port, LED lamp, water reservoir and circulating pump. Nutrient solution was circulated in the following order: reservoir ${\rightarrow}$ filtration-plasma or filtration-electrolysis ${\rightarrow}$ planting port ${\rightarrow}$ reservoir. The results showed that nutrient solution components and environmental parameters were changed by plasma or electrolysis treatment. Lettuce growth was not affected by the intermittent plasma or electrolysis treatment with 30 minutes or 90 minutes, respectively. The roots of the lettuce was damaged by excessive plasma and electrolysis treatment. Electrolysis treatment had greater effect on than plasma treatment because of the accumulation of high levels of TRO (Total Residual Oxidants).