• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.3
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• pp.35-45
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• 2021

Digestate or slurry produced from anaerobic digestion is mostly applied to crop lands for its disposal and recovering nutrients. However, minimizing nitrogen losses following field application of the digestate is important for maximizing the plant's nitrogen uptake and reducing environmental concerns. This study was conducted to assess the effects of three different biogas digestate application techniques (sawdust mixed with digestate (SSD), the hole application method (HA), and digestate injected in the soil (SD)) on nitrate leaching potential in the soil. A pot laboratory experiment was conducted at room temperature of 25 ± 2 ℃ for 107 days. The experimental results showed that sawdust application method turned out to be appropriate for quick immobilization of surplus N in the form of microbial biomass N, reflecting its lower total nitrogen and NH₄-N contents and low pH. The NH₄-N and total nitrogen fate in the soil fertilized with manure showed no statistically significant (p > 0.05) differences between the different methods applied during the incubation time under room temperature. In contrast, NO₃-N concentration indicates significant reduction in sawdust treatment (p < 0.05) compared to the control and other application methods. However, the soil sawdust mixed with digestate was more effective than the other methods, because of the cumulative labile carbon contents of the amendment, which implies soil net N immobilization.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.24-30
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• 2015

This study was conducted to select proper light intensity, pot media, and fertilization level for potted Hepatica asiatica Nakai native to Korea. The plants were grown under various light intensities (shading rate, 52, 82, 90, 97%) imposed by shading net. Plants grown with 52% shading showed a low survival rate (65%). Survival rate increased as shading increased, with over 80% survival in shading above 90%. Growth indexes such as fresh weight and leaf number did not show any significant difference between shading treatments. Plants grown in a soil mixture of decomposed granite:fertilizer-amended media:Kanumatsuchi (60:10:30, v/v/v) or river sand:fertilizer-amended media:bark (50:20:30) showed over 85% survival. However, plants grown in a soil mixture of river sand:fertilizer-amended media:Kanumatsuchi (50:30:20) or upland:river sand (40:60) showed very low survival, below 60%. Leaf number and plant height were the highest in a soil mixture of decomposed granite:fertilizer-amended media:Kanumatsuchi (60:10:30) as well. To select a proper fertilization level for H. asiatica, hyponex solution diluted 1,000- or 2,000-fold were applied weekly or biweekly. The survival rate was lowest at weekly application with 1,000-fold diluted solution, and no significant difference was observed between other treatments. In conclusion, H. asiatica exhibits preferences for very low light intensity and soil with air permeability, and is adaptable to a broad range of fertilization levels.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.279-290
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• 2021

This study evaluated the economic feasibility of facility farms according to the introduction of the ultra-high density pot cultivation (UHDPC) for mango. The basic model was selected as a representative farmhouse case in the Jeonnam region, and seven scenarios for conventional crops were tested. The economic feasibility of crop switching was analyzed through partial budget analysis (PBA). The PBA analysis results were supplemented by adding a sensitivity analysis and a break-even point (BEP) analysis. As a result of the analyses, it was found that crop conversion was economical because the increase in the profit coefficient was greater than the increase in the loss coefficient due to the introduction of mango for all conventional crops. The economics of introducing mango was more sensitive to changes in gross income than to changes in cost items. The results show the detailed conditions of crop selection according to the conditions and preferences of individual farms by presenting the direction of increase and decrease by budget item and information on the amount of increase or decrease. In particular, the BEP analysis result, which is about half of the farms case, is significant in that it presents the minimum target value according to production and market risks.

• Korean Journal of Plant Resources
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• v.20 no.1
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• pp.69-72
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• 2007

This study was performed to determine the effect of nutritional concentrations and fertilization intervals on growth of native pteridophyte (Pteris multifida, Cyrtomium falcatum, Cheilanthes argentea). Nutrient concentrations were treated with non-treat, 500X, 1,000X and 2,000X solution, and fertilization periods were treated in everyday, 5, 10 and 20day respectively, under the 30% shading net. Pteris multfida appeared to be very good for growth by fertilizing at intervals of 10 day with nutrient concentration of 2,000X drainage solution. The growth of Cyrtomium falcatum was the best in the treatment of $1,000{\sim}2,000X$ concentration for 10 days while that of Cheilanthes argentea was the highest in the treatment of 1,000X concentration for 5days.

• Korean Journal of Environmental Agriculture
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• v.17 no.4
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• pp.358-361
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• 1998

This study was carried out to develop a short term hardening method of tree seedlings of Rhus chinensis Mill., Evodia daniellii Hemsley and Parthenocissus tricuspidata(Sieb. et Zucc.) Planck for afforestation on a concave and a crack of cut-rock slope. The seedlings were grown in a cylinder shaped pot made of polyvinyl net with the soil media of peatmoss, vermiculite, clay, compost, fertilizer, and absorbant(40:25:19:15:1:0.1, v:v). They were cultivated in a greenhouse for four months and in field condition for two months. During the last three months of the growing period the seedlings were hardened by periodic desiccation and irrigation in 4 to 10 days interval. The hardened seedlings showed lower leaf water potential, higher leaf osmotic pressure, and lower T/R ratio than those before the hardening. The hardened seedlings survived well on the soil medium in the concave of cut-rock slope.

• The Korean Journal of Ecology
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• v.14 no.2
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• pp.211-230
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• 1991

The germinatin of e. annuus continued from the middle ofmay to mid-october. The maximum germination occurred on the mid-july. The period bloom of was distingushed amongs the different growth forms ; a orm pr of biennial and a form of pr perennial flowering from the mid-may to mid-september, and a form ps biennial blossom from the beginning of October to earlynovember. the dispersal of seed for(a form pr)occurred from early June to the mid-september. A rotte, germinating from summer to autumn, could classified into several growth forms; individuals without a critical leaf area for bolting until september and October, become a form ps of biennial, whicth did not proceed toreproductive growth unitl the next year, even thought wintering. individuals flowered on 3 years after germination become a form pr of perennial. The growth formular of aform pr of bennial, grown in a pot was w=20.2[1+$3.36{\times}10^3$(-0.062t)]$^{-1}$. The maximum relative growth rate(rgr) was 0.062g/g/day and the maximum net assimlation rate(nar) 0.089g/g/day. Therelative growth among each organ was shown as R=0.12 $T^{1.15}$between the avove-ground part(t) and the below- ground part(r). the relation between the avove-ground part(t) and the ratio of stem weight(wi) was ws/wi=2.56 $T^{0.35}$. n.p.k. was largely distributed on a leaf throughoutthe total growth period. while growing, it tended to decrease on the vegetative organ gut vice versa on the reproductive organ. however, nitrogen was more widely distributed on a leaf then in the reproductive organ.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.3
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• pp.9-14
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• 1980

This experiment was carried out to examine the effect of water stress at anthesis on the grain maturation and to interpret the immediate and resulting growth response in barley. The dry weight of root, stem, internode, flag leaf and grain under water stress was remarkably more reduced than that under no-water stress, respectively. Water stressed plants had heavier grain dry weight during 7.14 days after water stress than that under no-water stress, but this early response was reversed significantly in the later period. The relative turgidity of organs except grain under water stress was severely lowered than that under no-water stress. The net photosynthsis by rewatering after water stress had been kept at the lower level than that under no-water stress ti1l the late maturation.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3641-3649
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• 2022

A simple solvothermal reaction was used to prepare a 3-aminopropyl-functionalized silica-gel-based adsorbent for adsorbing Pd(II) from the nitric acid solution. Scanning electron microscopy, fourier transform infrared spectroscopy, and thermogravimetry analysis were performed on the as-synthesized adsorbent to demonstrate the successful introduction of Schiff base groups. Batch experiments were used to investigate the effects of contact time, nitric acid concentration, solution temperature, and adsorption capacity. It is worth noting that the prepared adsorbent exhibited a higher affinity toward Pd(II) with the uptake approximately 100% even in a 2 M HNO₃ solution. At an equilibrium time of 5 h, the maximum adsorption capacity of Pd(II) was estimated to be 0.452 mmol/g. The adsorbed Pd(II) could be completely eluted by dissolving 0.2 M thiourea solution in 0.1 M HNO₃. Using a combination of particle-induced X-ray emission analysis and an X-ray photoelectron spectrometer, the adsorbed Pd was found to be uniformly distributed on the surface of the prepared adsorbent and the existing species were Pd(II) and zero-valent Pd(0). Due to the desirable performances, facile preparation method, and abundant raw material source, the prepared adsorbent demonstrated a high application potential in the recovery of Pd(II) from simulated high-level liquid waste treatment.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.1
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• pp.1-9
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• 2022

In this study, the selection action on the mesh in the net pot for whelk (Buccinum opisthoplectum) is experimentally considered, and the selectivity was compared by the SELECT model and the Nashimoto's method with the probability model according to the contact shape of the mesh and the whelk. The experiments of the mesh size selectivity was conducted for two mesh sizes: 70 mm (inner stretched size 65.4 mm) and 44 mm (inner stretched size 39.5 mm). Selectivity experiments were conducted three times in total for each mesh size used 264 whelks. In addition, Nashimoto's method analyzed the retention probability using probability model for whether the mesh passed or not based on the carapace width of the whelk. As a result of the selectivity analysis, the 50% selection carapace width for the mesh size of 70 mm was similar to 43.62 mm in the SELECT model and 42.64 mm in the Nashimoto's method. However, the 44 mm mesh with relatively small mesh size showed differences of 40.01 mm and 26.80 mm, respectively. As for the mesh size selectivity of whelk, it was found that the smaller the mesh size, the lower the selectivity. In addition, in the selectivity study on the mesh size of whelk, an evaluation method that closely considers the contact shape between the mesh and the target species is required.

• Journal of Ecology and Environment
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• v.47 no.3
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• pp.85-102
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• 2023

Background: Ecophysiological characteristics of Rosa rugosa were analyzed under different environmental factors from May to October 2022. Photosynthesis, chlorophyll fluorescence, chlorophyll content, leaf water content (LWC), osmolality, carbohydrate content, and total ion content were measured to compare the physiological characteristics of R. rugosa at two study sites (i.e., in large pots and in the Goraebul coastal sand dune area). Results: When R. rugosa was exposed to high temperatures, photosynthetic parameters including net photosynthetic rate (P_N) and stomatal conductance (g_s) in both experiment areas declined. In addition, severe photoinhibition occurs when R. rugosa is continuously exposed to high photosynthetically active radiation (PAR), and because of this, relatively low Y(II) (i.e., the quantum yield of photochemical energy conversion in photosystem II [PSII]) and high Y(NO) (i.e., the quantum yield of non-regulated, non-photochemical energy loss in PSII) in the R. rugosa of the pot were observed. As the high Y(NPQ) (i.e., the quantum yield of regulated non-photochemical energy loss in PSII) of R. rugosa in the coastal sand dune, they dissipated the excessed photon energy through the non-photochemical quenching (NPQ) mechanism when they were exposed to relatively low PAR and low temperature. Rosa rugosa in the coastal sand dune has higher chlorophyll a and carotenoid content. The high chlorophyll a + b and low chlorophyll a/b ratios seemed to optimize light absorption in response to low PAR. High carotenoid content played an important role in NPQ. As a part of the osmotic regulation in response to low LWCs, R. rugosa exposed to high temperatures and continuously high PAR used soluble carbohydrates and ions to maintain high osmolality. Conclusions: We found that F_v/F_m was lower in the potted plants than in the coastal sand dune plants, indicating the vulnerability of R. rugosa to high temperatures and PAR levels. We expect that the suitable habitat range for R. rugosa will shrink and move to north under climate change conditions.