• Journal of the Korea Organic Resources Recycling Association
• /
• v.25 no.1
• /
• pp.15-21
• /
• 2017

In the present work, the synergistic effect of seaweed addition on organic acid production from sludge was investigated. The batch experiment was conducted at various mixing ratios of sewage sludge and seaweed (100:0, 75:25, 50:50, 25:75, 0:100 on a COD basis) under the substrate concentration of 20 g COD/L. The fermentation temperature was conducted under mesophilic condition ($35^{\circ}C$) and a heat-treated ($90^{\circ}C$ for 20 min) anaerobic digester sludge was used as a seeding source to suppress the methanogenic activity, The results showed that the amount of organic acid production increased as the content of seaweed increased: organic acids were 1.45, 3.22, 4.28, 5.24 and 4.82 g COD/L for the mixing ratio of 100:0, 75:25, 50:50, 25:75 and 0:100 respectively. The synergistic effect was calculated based on the organic acid production of individual sludge and seaweed, and was found to be 0.92, 1.14, 1.26 g COD/L at the mixing ratio of 75:25, 50:50 and 25:75, which indicates that 40% of synergy was obtained when 25% of seaweed was added. The synergistic effect could be ascribed to the high C/N ratio and biodegradability of seaweed.

• Asian Journal of Turfgrass Science
• /
• v.25 no.1
• /
• pp.59-68
• /
• 2011

Research was initiated to investigate the effect of high water-absorbing polymer on turf grass quality of three major turfgrasses. A total of 12 treatment combinations were used in the study. Treatments were made with different rates of sand, soil organic amendment (SOA), and water-swelling polymer (WSP). Visual turf grass quality was evaluated in creeping bentgrass (Agrostis palustris Huds., CB), Kentucky bluegrass (Poa pratensis L., KB), and zoysiagrass (Zoysia japonica Steud., Zoy) grown under greenhouse conditions. Significant differences were observed among the treatments in CB, KB, and Zoy. Visual quality ratings varied with mixing rates of SOA and WSP, being maximum 5.6 in differences among them. At the end of study it ranged from 0.3 to 9.6 in CB, 0.3 to 4.0 in KB, and 0.9 to 5.8 in Zoy. Turfgrass quality pattern changed with time after seeding among treatments influenced by WSP rates. From this study, a proper rate of WSP is considered to be 5%, 5~10%, and 5% for CB, KB and Zoy, respectively. In general, overall treatment effect of WSP on turfgrass quality was highly associated with SOA 20% in three turtgrass species. When mixing sand with SOA and WSP for rootzone soil, a proper rate of SOA is considered to be 15 to 20% for CB and KB, while 20% for Zoy of warm-season grass. A further study would be required to investigate the effect of varied, gradual mixing rates of WSP on growth characteristics of turfgrasses grown on mixtures of sand, SOA, and WSP before a field application.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.204-204
• /
• 2017

In recent years the growth rates of world agricultural production and crop yields have slowed because of rapid urbanization but the agriculture mechanization implies the use of various power sources and improved farm tools and equipment to enhance the efficiency of utilization of various crop input. Therefore the current study was conducted to investigate the growth characteristics of seedlings treated with plant growth regulators for the production of seeds suitable for mechanical formulations of soybeans and red beans. The seeds of Uram bean and Arary red bean were sown in 128 well plug tray as the testing varieties. Three growth inhibitors such as 0.05% hexaconazole, prohexadion-calcium, and 0.1% diniconazole were treated and fifteen representative plants were collected from each treatment at 2, 5, 7, 13, 16, 17, 19, and 20 days interval after treatment. The collected plants were examined for the growth atributes such as plant height, root length, leaf area and chlorophyll. The growth promoter was treated at the 13th day after treatment with growth inhibitor and treated with 0.1% concentration of Pomina ($GA_{4+7}$ 1.8% + 6-benzylaminopurine 1.8%) and Nonaji (gibberellic acid 2% + $GA_{4+7}$ 2%). Initially the growth data was recorded to examine the effect of growth inhibitor, while after treatment with growth promoters, the growth attributes were recorded at 4th and 7th day. As a result of measuring the growth parameter of soybean, the inhibitory effect was shown in the aerobic treatment at the ground level at the 7th day after treatment. At the 4th day of growth promoting agents treatment, the stimulation effect of non - treated plants was greater than that of formalin treatments. As a result of measuring the growth attributes of red bean, In the latter part of the growth, at the 4th day after the growth promoter treatment. This study was able to confirm the effective growth regulators and treatment periods for each crop, and it was possible to control the growth of seedlings. Based on these results, it can be expected that the basis of seedling production technology of crops which is necessary for sowing and transplantation mechanization of agriculturle field can be established.

• Weed & Turfgrass Science
• /
• v.3 no.1
• /
• pp.19-28
• /
• 2014

Research was initiated in greenhouse to investigate effects of polymer, calcium, perlite and chitosan on the growth of Kentucky bluegrass (KB). A total of 24 treatment combinations were used in the study. Treatments were made of water-swelling polymer (WSP), calcium, perlite, and chitosan in soil organic amendment (SOA). Significant differences were observed in germination rate, turfgrass coverage, turfgrass density and top growth among treatments. Germination rate, density and plant height varied with time after seeding. A proper mix of WSP is considered to be lower than 3% for turfgrass coverage and density. Regarding survival capability and top growth, however, it was good under 6%. Overall KB growth was more influenced by calcium and perlite than chitosan. Calcium and perlite were the most effective elements for early survival capacity and turfgrass density, respectively. But no effect was found by chitosan. Top growth increased with three elements, being perlite > calcium > chitosan. The chitosan was effective in early germination, but there was no effect on top growth until 3 weeks, when compared with others. A further study is needed for investigating the effect of these materials on the growth characteristics in mixtures of sand and SOA before a field application.

• Korean Journal of Weed Science
• /
• v.12 no.2
• /
• pp.183-187
• /
• 1992

This study was conducted to evaluate the effect of systematic herbicide application and polyethylene(PE) film mulching in direct seeded Angelica gigas Nakai. Freshly-collected-seed showed 86% of emergence rate and required 18 days of emergence duration. Cold treatment of seeds increased emergence rate by more than 90% and shortened 2 days of emergence duration. Paraquat) 1,1'-dimethyl-4,4'-bipyridylium dichloride was the most effective when applied just before emergence of A. gigas and provided 96% of emergence rate and 91% of weeding effect when applied 23 days after seeding. Soil applied herbicides used did not cause any phytotoxicity on emergence with application of 2-fold recommended rate and gave more than 90% of weeding effect. Black PE film mulching gave excellent emergence rate and weeding effect, and shortened emergence duration by 8 days.

• Korean Journal of Agricultural Science
• /
• v.38 no.1
• /
• pp.17-23
• /
• 2011

This research was conducted to investigate the influence of application rate of liming fertilizers on changes in soil chemical properties and growth of 'Red Madness' petunia in plug production. To achieve this, dolomite (DO) with 0, 1.0, 3.5, 8.0 or 13.0 $g{\cdot}L^{-1}$ and calcium carbonate (CC) with 0, 2.0, 2.5, 3.0, 3.5, or 4.0 $g{\cdot}L^{-1}$ were incorporated into peatmoss + vermiculite (1:1, v/v) during the root substrates formulation. The treatments of 3.5 $g{\cdot}L^{-1}$ of DO and 2.5 or 3.0 $gL^{-1}$ of CC had acceptable ranges of pH and EC in soil solution such as 5.6~6.2 and 0.7~1.0 $dS{\cdot}m^{-1}$, respectively. The faster rising of pH was observed in root media containing CC rather than those of DO. This indicates that the solubility of CC is higher than DO. The soil Ca concentrations in all treatments of CC were 1.8 times as high as those of DO. The treatments of 3.5 or 8.0 $g{\cdot}L^{-1}$ of DO had the highest soil Mg concentrations, but all treatments of CC had lower soil Mg concentrations than control treatment indicating that additional application of Mg fertilizers are required. The elevated application rate of DO or CC resulted in the increase of fresh and dry weight. But plant heights were not influenced by application of liming fertilizers. The results of tissue analysis showed that application of DO or CC influenced the $PO_4{^-}P$, Ca and Mg contents, but not influenced the contents of other nutrients such as N, P, Fe, Mn, Zn and Cu.

• Horticultural Science & Technology
• /
• v.19 no.4
• /
• pp.511-514
• /
• 2001

Pelleting the seeds often reduces seed germinability. In an effort to alleviate this problem, the seeds of four carrot cultivars were, before pelleting, either solid-matrix primed (SMP) with Micro Cel-E or osmotically-primed with polyehtylene glycol 8000. Some batches were imbibed in 100-ppm $GA_3$ solution. In laboratory tests, pretreatment of the seeds increased the precentages of germination by as much as 50% of the controls, indicating the increase of the germination speed by 1.9 to 4.6 days as determined by the $T_{50}$ values. In field tests conducted in the year of 2000 and 2001, however, effects of SMP were not observed. There was no significant difference between the SMP seeds and the controls of the percentages and $T_{50}$ values. The emergence of the seedling in the field was affected greatly by soil water concentration.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.4
• /
• pp.360-365
• /
• 1993

The infant seedling of rice(8-to 10-day-old) has often suffered from submergence just after transplanting due to the too short seedling height, 5 to 8cm, This experiment was conducted to elucidate the effect of gibberellic acid($GA_3 : 25% soluble liquid) with the application methods of foliar spray and seed-soaking on the elongation of seedling height of infant rice seedling in machine transplanting, We used a japonica rice variety, Hwaseongbyeo, and the seeding rate was 200g per seed tray(30$\times60$\times3cm). Generally,$GA_3 and Metalaxyl increased the elongation of seedling height of infant seedling while Tetracycle decreased the seedling height, To increase the seedling height of infant seedling, the foliar spary application of $GA_3 was better than seed-soaking treatment. The optimum concentration of $GA_3 for the foliar spray was about l0ppm and the optimum application time of $GA_3 was 3 to 4 days after sowing.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.43 no.2
• /
• pp.66-70
• /
• 1998

Four introduced forage rape (Brassica napus) cultivars, 'Akela', 'Ramon', 'Sparta', and 'Velox' and a leading rapeseed cultivar, 'Hallayuchae' were grown at nitrogen (N) rates of 0, 100, 250, 300, 350, and 400 kg/ha to (i) select forage rape cultivars adapted best to Cheju area, and (ii) determine the optimum N rate for the best cultivars. Days from seeding to flowering across the cultivars increased 190 to 195 days as N rate increased from 0 to 400 kg/ha. Average days to flowering of six cultivars ranged from 182 to 198 days. Plant height increased as N rate increased up to 300 kg/ha and then decreased with a further increase in N rate and ranged from 159 to 174 cm among the cultivars. The optimum N rate for the greatest dry matter yield of five cultivars ranged from 222 to 258 kg/ha. Sparta showed the greatest dry matter yield (35.79 Mg/ha), followed by Akela, Hallayuchae, Velox, and Ramon. As N rate increased, crude protein content linearly increased but crude fiber content declined curvilinearly. Akela and Sparta had higher protein content than the other cultivars did. The forage cultivars had lower crude fiber content than the oilseed cultivar Hallayuchae did. Our results demonstrated that Sparta was best adapted to Cheju area and the optimum N rate for Sparta was about 220kg/ha.

• Korean Journal of Soil Science and Fertilizer
• /
• v.15 no.4
• /
• pp.251-257
• /
• 1982

Fatty acid and sterol composition of soybean seedlings was investigated by treatment of light irradiation time. The results obtained were as follows; 1. In hypocotyl of seedlings, the proportion of linoleic and linolenic acid was in creased with increasing light irradiation time, while those of palmitic and stearic acid was decreased. 2. In root of seedlings, the proportion of palmitic and linolenic acid was decreased with increasing light irradiation time, but those of stearic and oleic acid was in creased 2 days after germination. 3. Throughout their growth, the main sterol of cotyledon was the stigmasterol but that of in hypocotyl and roots was sitosterol. 4. On 6 days after planting, the content of sitosterol was the highest in hypocotyl of seedlings recieved 24-hour irradiation. 5. The proportion of sitosterol in root was decreased with growth duration under the dark and 24 hour-irradiation condition while increased under 16 hour irradiation.