• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.413-419
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• 2009

The appropriate dripper position in perlite bag was investigated for tomato production. Drippers were laid at 5(F5), 15cm (F15) away from the stem base or 5cm at first and then moved to 15cm later (M5-15). Roots were developed more near the stem base in F5, while less in F15. Roots were distributed evenly in M5-15. In vertical distribution of water in perlite bag, water content was higher as it went deeper with the variation by dripper positions. Yield was high in F15 and low in F5. In conclusion the position of dripper is the best at 15cm from the stem base in perlite bag culture in view of root distribution and yield.

• Journal of Bio-Environment Control
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• v.16 no.1
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• pp.40-46
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• 2007

This study was conducted to clarify the effects of the different substrates in terms of perlite (100%), peat moss (100%), granular rock wool (100%) and mixing perlite (50%) with peat moss (50%) on the growth responses and mineral contents of hydroponically grown Plantago asiatic in aggregate culture. Overall early plant growth such as plant height, stem diameter, number of leaves, root length, fresh and dry weight of shoot and root were increased in the order of that miked perlite and peat moss (50%:50%, v/v)>peat moss (100%)>granular rock wool (100%)>perlite (100%). Ca and Mg contents in plants became highest in the plants grown in the peat moss, however, Mg and Na in the granular rock wool. $P_2O_5$ content in plants were most increased in proportion to the plant growth increment in the peat moss (100%) and the mixing substrates of perlite and peat moss (50:50, v/v).

• Journal of Bio-Environment Control
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• v.10 no.2
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• pp.88-94
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• 2001

Physical and chemical properties, the salt accumulation and leaching of salt by water of coal fly ash ball (ash ball) were evaluated in comparison with perlite and granule rockwool (rockwool). Bulk density, particle density, solid phase, and porosity of ash ball were 0.93 g.cm$^{-3}$ , 2.29 g.cm$^{-3}$ , 40.6%, 59.4%, respectively. The bulk density of ash ball was greater, while porosity was smaller, than that of perlite and rockwool. Saturation moisture capacity was 52% in ash ball, 71% in perlite, and 90% in rockwool. Water contents after drainage for 1 hr of ash ball, perlite, and rockwool were 21%, 27%, and 80%, respectively. Water content of small granules (3-5 mm) of ash ball was 5% greater than that of large (7-15 mm) grannules. The ash ball was a weak alkali substrate with pH 7.6, but not electric conductivity (EC), of the nutrient solution supplied to ash ball slightly increased. When the absorption of mineral ions to substrates were analyzed, ash ball and RW absorbed mainly PO￣$_4$. On tomato culture, salt accumulation in ash ball substrate was similar to that in perlite. Most of the salts in the ash balls were removed by submerging the substrate eight times in distilled water. It is concluded that water holding capacity of ash ball substrate was lo as compared to other substrates, but air permeability, and water diffusion was excellent, making control of medium water content easy.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.228-232
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• 2007

We have also clarified the effects of the different substrates; (perlite, peatmoss and granular rock-wool) on the plant growth and the mineral contents of Campanula takesimana until 70 days after transplanting. Overall plant growth in terms of plant height, stem diameter, number of leaves, root length, fresh and dry weight of shoot and root were increased in the order of that mixed perlite and peat moss (50 : 50, v/v)>peat moss (100%)>perlite (100%)>granular rock wool (100%). Mineral contents in plants were much more in the order of potassium $(15.38-43.91cmol^+/kg)$, calcium $(5.48-7.78cmol^+/kg)$, magnesium $(4.38-6.55cmol^+/kg)$ and sodium $(1.25-1.69cmol^+/kg)$. The higher mineral contents of plants were also most made in the mixed substrates of perlite and peat moss (50 : 50, v/v).

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.292-299
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• 2022

This study was conducted to analyze physical and chemical properties of horticultural substrates and response of hydroponically grown two cultivars of 'Namcheon' and 'Somirang' perilla by four different substrates: coir (chip:dust = 5:5), perlite, granular rockwool, and commercial mixed substrate (cocopeat:peatmoss:vermiculite:perlite: zeolite = 50:25:10:10:5). There were no significant differences in EC and pH according to substrates. Container capacity was the greatest in granular rockwool, and it showed appropriate levels in mixed substrate and coir. Air space was higher in coir and perlite than the other treatments. Bulky density reached a proper standard in all substrates excepting coir. The leaf length and width of 'Namcheon' indicated the most in mixed substrate, though the value of 'Somirang'was greatest in coir substrate. The leaf weight of both cultivars was highest in mixed substrate, and relatively low in coir and perlite. The total yield of leaves was separated by two groups: higher group, which are mixed substrate and granular rockwool, and lower group, which are coir and perlite. There was a large gap by 28% between these two groups. Therefore, this study suggests that substrates with high water holding capacity such as mixed substrate or granular rockwool are most suitable for the hydroponic cultivation of perilla, which require sufficient moisture supply to the root zone.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.257-263
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• 2006

This experiment was conducted to investigate the optimal media for 'Pechika' ever-bearing strawberry grown in hydroponic culture system in summer highland. Three mixed media (1:1, v/v) of peatmoss with perlite, rice hull, and granular rockwool, and four solution strengths of EC 0.5, 0.75, 1.0 and $1.25 dS{\cdot}m^{-1}$ were tested. Root zone temperature in peatmoss+perlite media was 1 to $3^{\circ}C$ lower than in the other media. The culture medium of mixing to peat moss and perlite was most effective in producing good yield and fruit quality. The culture medium of mixing to peat moss and perlite was the highest about 1,632kg/10a to yield yearly average, but was very undulating 732 kg/10a to yield in 2004 year and 3,013kg/10a in 2003 year. The deformed fruits were increased when the solution strength was increased, especially in EC $1.25dS{\cdot}m^{-1}$. The soluble solids and the acidity content of fruits were increased with higher solution strength regardless of media. The uptake of Ca and Mg was inhibited at higher solution strength, and the uptake of N, P and K was promoted. Therefore, the culture medium of mixing to peat moss and perlite was the most suitable culture medium to product strawberry in summer, because it had the highest yield even though fruit quality among treatments was not significant.

• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.159-166
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• 1995

This experiment was aimed to investigate the growth and yield responses of hydroponically grown cucumber as affected by cultural containers and substrates using perlite and mixtures with perlite. Containers used in this experiment were bed and box made of styrofoam, PE film and Wagner pot and substrates used were perlite, peatmoss, rice hull and carbonized rice hull. The results obtained were as follows : Based on the growth and yield responses determined from the leaf area and total fruit weight, bed and box made of styrofoam was considered the best containers among tested for cucumber hydroponics. Recommendable substrates for hydroponically grown cucumber using perlite were evaluated in the order of perlite, perlite with rice hull and perlite with carbonized rice hull in styrofoam bed and box. Increase in marketable yield and decrease in abnormal fruits was observed in the mixed substrates with rice hull or carbonized rice hull when compared to perlite single media.

• Journal of Bio-Environment Control
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• v.9 no.1
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• pp.20-26
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• 2000

This study aims at analyzing physical and chemical properties of perlite substrate. Particles of substrate were divided into five categories In size: gravel, very-coarse, coarse, medium and fine grade. Particles of very-coarse and greater grades in perlite substrate occupied 98.5％ of total particles. The air phase of total particles was distributed between 76.8％ and 87.7％ with especially showing that of very-coarse grade was lower than that of coarse or smaller one. However, the liquid and solid phases were vice versa. The cation exchange capacity (CEC) measured was highest in the fine grade. In drainage experiments, the water being drained from the substrate increased with the ratio of drain area, and the 65~70％ of total water reduced within five minutes after irrigation. The drained volume was proportional to the depth of the substrate, which contained about 2mL.cm$^2$：by depth (cm). Due to quick reduction of the water in the substrate, the pF value increased in four minutes after irrigation and showed the highest negative correlation ($R^2$＝0.997) with the moisture content of the substrate. The physical and chemical properties including drainage characteristics analyzed in this study can be, therefore, utilized to control the moisture content of perlite substrate, efficiently.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1999.11a
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• pp.71-74
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• 1999

농업ㆍ원예분야에서 다공질 재료를 인공배지로 이용하기 위하여는 수분관리의 용이성, 우수한 양분의 유지, 통기성 및 보수성이 요구된다. 이들 성질을 만족시키는 재료로는 점토, 벤토나이트, 질석(vermicutite), 펄라이트(perlite) 및 락-울(rock-wool) 등이 이용된다. 인공배지 재료로 널리 사용되는 펄라이트와 락-울의 원료는 중국 및 호주 등지로부터 수입에 의존하고 있어 양액재배 농가에 커다란 부담이 되며 건습조절이 곤란하여 배지 내 수분함량의 조절이 용이하고 양액사용이 간편한 배지 및 폐기처리시 환경문제를 야기하지 않는 반영구적이며 자연친화형의 배지의 개발이 절실히 요구되고 있다. (중략)

• Journal of agriculture & life science
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• v.44 no.5
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• pp.9-13
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• 2010

This study was conducted to identify the possibility of utilization of coconut substrates for nutrition culture of cut-chrysanthemum. The materials of substrate were composed of dust, fiber, and chip from coco-nut fruit. Dust was used in dust (100%), and dust+chip and +fiber were used in the ratio of 7:3 (v:v), respectively, as coconut mixture substrate. Perlite was used as control in this experiment. Water content in the perlite medium was lower than in dust substrate. The pH of all coconut substrates ranged from 6.5 to 5.8, whereas perlite substrate ranged from 7.3 to 6.7. While, EC of dust substrates shown to be highest but perlite substrate was lowest. The growth of chrysanthemum such as stem length, leaf area, and dry matter showed better results in coconut substrates than that of perlite and dust. However, there was no differences days to in flowering among treatments.