• Horticultural Science & Technology
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• v.33 no.1
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• pp.47-54
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• 2015

This research was conducted to investigate the changes in moisture retention capacities of expanded rice-hull (ERH)-based root media and their influences on the growth of mother and daughter plants in vegetative propagation of 'Seolhyang' strawberry. The proportion of water at the container capacity of ERH medium was in the range of 20 to 23%. This range was lower than the 60 to 66% of strawberry-specialized medium, the 30 to 34% of soil mother material (SMM) and the 30 to 35% of loamy sand. The moisture content of ERH was reduced to 10 to 12% at 8 hours after irrigation, and there were large variations among replications of ERH medium. Among four kinds of root media formulated to contain ERH, the medium of ERH + coir dust (CD) (55 + 45%, v/v) had 26.5 and 32.5% water contents at 20 and 40 days after irrigation to daughter plants, respectively. The m edia o f ERH + sandy loam (S L) and E RH + S MM showed similar trends i n moisture r etention. The pH and EC i n the all root media tested were in the range of 6.7 to 7.1 and 0.03 to $0.08dS{\cdot}m^{-1}$, respectively. The pHs and ECs measured at 20 and 40 days after irrigation were not significantly different in each root medium. Among the root media formulated to contain ERH, the growth of daughter plants was the highest in the treatment of ERH + SL (55 + 45%, v/v). As the blending rate of coir dust was elevated in the ERH + CD media, moisture retention capacity increased gradually, but the growth of daughter plants became worse even though the medium showed higher moisture retention capacity than other root media tested. The growth of roots and aboveground tissues of daughter plants deteriorated in the root media formulated by blending ERH + perlite (PE) at various ratios. The results of this research suggest the optimum formulations of root media and management of moisture content in raising of strawberry daughter plants when ERH is a component of root media.

• FLOWER RESEARCH JOURNAL
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• v.16 no.1
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• pp.36-43
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• 2008

This purpose of this study was to examine the effect of planting density, growing medium and strength of a nutrient solution (National Horticultural Research Institute's nutrient solution: HRI's) on the growth and development of Oriental hybrid lily 'Le Reve' in a box cultivation. The planting density with 14, 18 and 22 bulbs had sprouting one day earlier than other treatments. Planting density of 22 bulbs flowered first, while six bulbs flowered the last, indicating that higher planting densities led earlier flowering. The increasing planting density increased stem length of cut flowers. On the other hand, cut flower quality was improved when the planting density was lower. The incidence of physiological disorders such as blasting was more frequent in planting density of 22, 18, and 14, indicating that higher planting densities caused higher incidences of physiological disorders. All planting densities except 22 bulbs displayed superior results in width, weight, number, and scale weight of the bulbs. Greater planting densities led to inferior bulb enlargement and an increased decomposition rate. pH decreased in all treatments after the bulb enlargement and decreased more as the planting density increased. Contents of P, K, Ca, and Mg increased, while contents of K and Ca decreased, as the planting density increased. The rice hull+coir (1:1, v/v) treatment was better than others, but did not show that much of a difference. Moreover, in bulbs enlargement after cut flower harvest, lily medium and perlite+peat moss treatments showed superior results, and decomposition rate was the greatest in the rice hull+coir (1:1, v/v) treatment. In the HRI's solution strength treatment from the period of flower bud emergence to flower harvest, higher solution strengths gave better cut flower quality in terns of length, weight, and number of flowers. The non-treated control and one third strength of a HRI's solution hastened flowering, indicating that lower strengths led to earlier flowering. According to the results of leaf analysis as affected by solution strength during the flower harvest, absorption rates of N and K were greater when the strength was higher, and Ca and Mg showed the same tendency. On the other hand, the absorption rate of P was the lowest in all treatments.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.4
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• pp.296-306
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• 2014

This study was conducted to survey and analyze the quantity of various organic wastes and to vitalize the utilization of agri-food by-products as raw materials for Total mixed ration (TMR), to improve feed cost savings and the quality of animal products. On-the-spot obstacles for animal farmers, along with legal and institutional alternatives are presented. The results are as follows. First, organic wastes in Korea are managed by the Allbaro system created in the Wastes Control Act, which processes 10,488 tons of cooking oil waste, 832,493 tons of animal and plant residues, 5,740 tons of animal carcasses, 1,171,892 tons of animal residues, and 2,172,415 tons of plant residues including 12,905 tons of rice hull and bran, for a total of 4,205,931 tons. Raw materials for TMR, namely rice hulls and bran as well as plant residues, accounted for 51.7% of the total national organic waste. The top 10 municipalities process 76~100% of all organic wastes and a supply management system is needed for the waste. Second, the 10 major agri-food by-products used as raw materials for TMR are bean curd by-product, rice bran, oil-cake, brewers dried grain, Distiller's Dried Grains with Solubles (DDGS), barley bran, soy sauce by-product, citrus fruit by-product, mushroom by-product and other food by-product (bread, noodles, snacks, etc.). Third, the biggest difficulties in using agri-food by-products are legal obstacles. Because agri-food by-products are regulated as industrial wastes by the Waste Control Act, animal farmers that wish to use them have legal reporting obligations including the installation of recycling facilities. To enable the use of agri-food by-products as raw materials for TMR, waste management system improvements such as 'the end of waste status' and the establishment of more than 10 public distribution centers nationwide are deemed essential.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.764-769
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• 2010

We investigated influence of continious application of gypsum (G: $CaSO_4{\cdot}2H_2O$), popped rice hulls (H) and zeolite (Z) on soil aggregation of reclaimed sandy loam soils. The application rates amended to fine sandy loam from reclaimed soils at Kyehwado were varied as follows:1550 (G1), 3100 (G2), 6200 (G3), 1000 (H1), 2000 (H2), 3000 (H3), and 200 (HZ1), 400 (HZ2) and 800 (HZ3) added to 1500(H) kg $10a^{-1}$, respectively. Soil aggregates were analyzed for 60, 90 and 120 days after treatments (DAT). At 60 DAT, The amount of aggregate from soil samples treated with gypsum was slightly increased with G1 while the aggregation was decreased by 4.66% for G3 for soil aggregates than thar of control. The treatments of H or HZ were effective in soil aggregation. The effect of treatment was in the order of H > HZ > G. At 90 DAT, increasing amount of gypsum attributed to decrease in soil aggregates. Therefore, we could conclude that suitable amounts of gypsum for soil aggregation in fine sandy loam might be 1550 kg $10a^{-1}$ or less. H1 increased aggregation by 7% for aggregate size between 1.0 and 2.0 mm. HZ1 was most effective in aggregation by 52.78% among the treatments while H2 and HZ3 51.50% and 48.51% at 120 DAT, respectively. As a result, we found that the effect of the treatment for soil amendments was in order of H > HZ > G.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.1
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• pp.24-29
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• 1984

Seedling yield of panax ginseng depended on soil water in a modified Yang-jig seedbed with rice hull mulch and peat application which increased soil water content. Water dependency tended to increase with the increase of potassium in soil. Effect of potassium on water dependency seemed to be constant in certain range of soil water which might be the optimum water for seedling growth. Partial correlation coefficient between seedling yield and water was significant in relation to organic matter (OM), Mg and Ca. The best multiple regression of seedling yield was with $H_2O$, K and Ca. Available phosphorus (P) in soil increased with low level of peat but decreased with high level or with mulching. There was interaction between mulching and peat for P. There was significant linear relation between two of pH, $H_2O$, Ca, Mg, K, OM except between K and $H_2O$ or pH. Ammonium nitrogen negatively correlated with Mg Quadratic relation held between $NO_3-N$ and K or $NH_4-N$ and between P and K+Ca+Mg. Quadratic relation was more significant than linearity between soil factors. Mulching increased stem length. Leaf area index ranged from 1.06 to 1.67. Leaf area per plant ranged $16.0-18.8cm^2$.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.189-196
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• 2015

This study was performed to identify the effect of mixed bed soil on growth of aerial parts and root zone of daughter plants for nursery field strawberry seedling raising with expanded chaff. The plant height and leaf area of daughter plants were highest or largest in the mixed soil of ERH +RH (100:0, v/v), followed by ERH+RH (75:25). The higher the mixing ratio of RH, the shorter the plant height or the smaller the leaf area. A similar tendency was observed in fresh weight. Within a root diameter of 0-0.4 mm and a root height range of 0.4-0.8 mm, root surface area and volume were statistically significantly better with treatment of ERH+RH (100:0, v/v) compared to those of roots treated with ERH+RH (75:25), ERH+RH (50:50) and ERH+RH (25:75). The growth rate of aerial parts and root zone of daughter plants were noticeably lower in two mixing ratios of 50:50 and 25:75. According to the mixing ratios of ERH+CD surface treatment, the number of roots was greatest in plants treated with ERH+CD (80:20, v/v) and ERH+CD (85:15) on August 1. However, the number of roots was highest in plants treated with ERH+CD (85:15, v/v) on August 15. Root length was longest in the plant with no treatment, and drastically shortened from ERH+CD (90:10, v/v) in both surface and mixed treatment. Although root weight showed a significant difference in ERH+CD (90:10, v/v) treatment, its increase was gradual. The rate of root growth was highest in ERH+CD (85:15). These study findings suggest that the content ratios of mixed soil ERH+RH (75:25, v/v) or below and ERH+CD (85:15) are thought to be desirable for the production of high quality seedlings.

• Korean Journal of Environmental Agriculture
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• v.9 no.1
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• pp.53-59
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• 1990

Root zone environments in hydroponics are very important factors in crop growth, development and quality. In Korea, improvement of root zone temperature is required because of the continental climate. Therefore, this investigation was carried out to clarify the difference of root zone environments in different hydroponic systems under different climates. Tomato plants were grown in nutrient solutions at Seoul City University and Allen Cooper's. Hydroponic systems in this experiment were aeroponics, nutrient film technique(NFT), rockwool culture, sand culture and smoked rice hull culture(SRH). The decrease in temperature rapidly occured in sand culture while slowly in rockwool culture in low air temperature periods. The internal temperature of substrates of hydroponic bed were slightly changed in rockwool culture under high air temperature periods, while the duration of high temperature was longest in NFT. Electrical conductivity and pH of nutrient solution showed great changes in rockwool and aeroponics. Along the bed, the content of dissolved oxygen in nutrient solution had a tendency to decrease in NFT and DFT(Deep flow technique), while didn`t a change with aeroponics. Root activity measured by triphenyl tetrazolium chloride (TTC) was highest with aeroponics, followed by rockwool culture and NFT.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.2
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• pp.55-58
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• 2004

The objective of this study was to get information about water retention characteristics of horticultural substrates used in Korea determined by European standard method. Water retention curves were prepared at water volume (v/v, %) in relation to -10 cm, -50 cm, -100 cm water pressure head. Water retention curves showed different properties depending upon the type, the place of origin, particle size, and manufacturing processes of substrates. Peat and coir had easily available water content in the range of 30-40% and showed high water holding capacity, water buffering capacity, and aeration for plant growth. However, bark, sawdust and rice hull showed low water holding capacity about below 10%. The easily available water content of perlite and clay ball was low about 0.1-13.8%, whereas that of vermiculite and rockwool granulate was high about 25.9-52.0%. Understanding water retention characteristics of growing substrates is very important in cstablisliing optimum condition for plant growth. Further study on water retention curves for more substrates, mixture and growing media is needed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.208-212
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• 1993

Since ramie suckers distribute soil surface layer within 10cm depth, some of them are dead from low soil temperature in winter. An experiment was conducted to investigate the effects of various mulching methods on safe overwintering of sucker at three or four years old, fully-grown ramie plots. The sprouting dates of ramie was March 28 in transparent vinyl mulching(TPEF), April 1 in transparent vinyl mulching over cover of straw, manure or rice hull at the amount of 500kg /10a (CM), and April 6 in black vinyl mulching(BDEF). These treatments showed earlier sprouting date from 9 to 18 days than the conventional mulching with 1000 kg straw /10a the sprouting date of which was April 15. TPEF treatment showed the earliest but ununiform sprouting. In contrast, sprouts in CM treatment was uniform but emerged somewhat later compared with the treatment of TPEF. The number of stems per unit area increased 50 percent more in TPEF, and 35 to 39 percent more in CM than the treatment of conventional mulching.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.338-341
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• 2001

A new passive nutrient supplying system (PNS) was designed. The experiment was conducted to compare PNS with automatic hydroponic system (AHS) by investigating the growth characteristics of muskmelon (Cucumis melo L.) in spring and summer. No significant differences in growth characteristics of leaf area and shoot dry weight were observed between PNS and AHS. However, better netting of melon fruit was shown in PNS. Sugar content of melon fruit was also $1.0-2.0Brix^{\circ}$ higher in PNS than in AHS. The suitable substrate for melon culture with PNS was the mixture of perlite 70% and rice hull 30%. These results suggested that new PNS could be introduced to growers without any loss of fruit yield and quality of muskmelon.