• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.57-63
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• 2007

Due to the strong influence of nitrogen(N) on plant productivity, a vast amount of N fertilizers is used to maximize crop yield. Over-use of N fertilizers leads to severe pollution of the environment, especially the aquatic ecosystem, as well as reducing farmer's income. Growing of N-efficient cultivars is an important prerequisite for integrated nutrient management strategies in both low- and high-input agriculture. Taking maize as a sample crop, this paper reviews the response of plants to low N stress, the physiological processes which may control N-use efficiency in low-N input conditions, and the genetic and molecular biological aspects of N-use efficiency. Since the harvest index(HI) of modern cultivars is quite high, further improvement of these cultivars to adapt to low N soils should aim to increase their capacity to accumulate N at low N levels. To achieve this goal, establishment and maintenance of a large root system during the growth period may be essential. To reduce the cost of N and carbon for root growth, a strong response of lateral root growth to nitrate-rich patches may be desired. Furthermore, a large proportion of N accumulated in roots at early growth stages should be remobilized for grain growth in the late filling stage to increase N-utilization efficiency. Some QTLs and genes related to maize yield as well as root traits have been identified. However, their significance in improving maize NUE at low N inputs in the field need to be elucidated.

• Journal of Bio-Environment Control
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• v.17 no.3
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• pp.210-214
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• 2008

This experiment was carried out investigation of optimum concentration of supply nutrient solution in hydroponics of sweet pepper using coir substrates (coconut dust fiber=70% : 30%, v/v). During the growing period, it was found out that the electric conductivity (EC) would increase in proportion to the supply nutrient concentration but it was in inverse proportion to the moisture content. The pH of drainage was stable, while EC was high showing EC $7.3\;dS{\cdot}m^{-1}$ in EC $4.0\;dS{\cdot}m^{-1}$ of supply nutrient concentration. Also, standard deviation and coefficient of variation were high. Plant length was no difference by the supply nutrient concentration. Photosynthesis rate was generally high in supply nutrient concentration EC$4.0\;dS{\cdot}m^{-1}$. Fruit weight was heavy in supply nutrient concentration EC $4.0\;dS{\cdot}m^{-1}$, fruit shape was close to a regular square in supply nutrient concentration EC $3.5dS{\cdot}m^{-1}$.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.1
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• pp.1-7
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• 2014

The objective of this study was to determine the effect of single and co-inoculation of plant growth promoting bacteria (PGPB) on early plant growth in Saemangeum reclaimed soil. Plant growth promoting Brevibacterium iodinum RS16 and Methylobacterium oryzae CBMB20 were inoculated on maize (Zea mays L.) and sorghum-sudangrass hybrid (Sorghum bicolor L.) grown in Saemangeum reclaimed soil. Single and co-inoculation of B. iodinum RS16 and M. oryzae CBMB20 increased plant height, dry biomass accumulation and macro-nutrient accumulation of maize and sorghum-sudangrass hybrid. M. oryzae CBMB20 treatment increased plant height in maize by 41.2% at 30 days after sowing (DAS), shoot dry weight and total dry weight compared to non-inoculated treatment. Macro-nutrient accumulation (N and P) in maize roots was significantly increased with co-inoculation treatment, K and Ca content was significantly increased at B. iodinum RS16 treatment compared to non-inoculated treatment. Macro-nutrient accumulation (P, K, Ca and Mg) in shoot was higher with M. oryzae CBMB20 treatment compared to non-inoculated treatment. In case of sorghum-sudangrass hybrid, co-inoculation treatment showed 33.7% increase in plant height compared to non-inoculated treatment at 30 DAS. M. oryzae CBMB20 treatment increased root dry weight and total dry weight, macro-nutrient accumulation in roots and N, Ca and Mg accumulation in shoot compared to non-inoculated treatment. P and K accumulation in shoot was significantly increased at co-inoculation treatment compared to non-inoculated treatment. This pot culture experiment demonstrated that single and co-inoculation of B. iodinum RS16 and M. oryzae CBMB20 increased the early growth and nutrient accumulation of maize and sorghum-sudangrass hybrid.

• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.71-77
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• 2012

The performance and characteristics of nutrient removal in wetlands influenced by plant type. We tested a floating plant, Eichhornia crassipes, and a submerged plant, Ceratophyllum demersum, under the same environmental conditions to understand the differences in nutrient uptake by these different plant forms. The total nitrogen and phosphorus in the water decreased in the following order: Water Only < Water + Soil < Floating Plants ${\approx}$ Submerged Plants and Water Only < Water+Soil < Floating Plants < Submerged Plants. Nitrogen and phosphorous concentrations increased in both plants; however, the phosphorous concentration was greater in C. demersum than E. crassipes. The submerged plant exhibited higher phosphorus uptake per unit biomass than the floating plant, but nitrogen uptake did not differ significantly. These results suggest that the presence of soil influences nitrogen and phosphorus removal from water, and that wetland plants play an important role in the assimilation and precipitation of phosphorus. Understanding the differences in contaminant removal performance and characteristics of various plant forms can help in the selection of diverse plants for constructed wetlands to improve water quality and provide ecosystem services such as wildlife habitat and landscape enhancement.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2006.05a
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• pp.291-295
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• 2006

• Plant Resources
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• v.8 no.1
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• pp.75-79
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• 2005

TO select the most suitable crop and variety of forage for nutrient quality at the southern part of Korea, the crop of wheat, barley and rye were grown from Oct. 1999 to June 2000. Paldanghomil variety of rye crop was shown to have the highest chemical components in comparison to other varieties of crops used in this experiment. It showed relatively high content of crude protein and in vitro dry matter digestibility (IVDMD) and low content of NDF, ADF, cellulose and lignin. Therefore, it was concluded that paldanghomil of rye crop was the most suitable variety with high weight and high nutrient quality for forage in the southern part of Korea. The heritabilities of all nutrient quality characters were estimated to be high.

• Journal of Bio-Environment Control
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• v.10 no.2
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• pp.101-105
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• 2001

Plant roots are affected by the root zone environment rather than substrate material itself. It is important to provide a suitable environment for the roots by amending the substrate and adjusting supply of the nutrient solution. In an expanded rice hull substrates, 1.5 L nutrient solution was supplied on each day at different frequency. In rice hull substrate, plant growth and yield were the greatest in the treatment where a 1.5L nutrient solution was supplied as 24 equal aliquots, wheres in perlite substrate plant growth and yield were the greatest in the treatment with 16 aliquots. Nitrogen deficiency symptoms caused by early decomposition of rice hulls by microorganisms was recovered by increasing solution EC from 1.7 to EC 2.0 dS.m$^{-1}$ for 25 days after planting. Plant growth and yield increased in the treatment of Ec 3.0 dS.m$^{-1}$ , but the cause for this increase is not clear.

• Journal of Practical Agriculture & Fisheries Research
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• v.18 no.1
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• pp.37-45
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• 2016

In order to obtain the optimum application time of liquid pig manure (LPM) for growth and nutrient contents of green manure crops (GMCs), the growth and nutrient characteristics of GMCs were evaluated under different application times of LPM in pot experiment. GMCs were sown in Sept. 1, 2012. LPM was treated in soil surface at 15 days before sowing (15DBS), at 0 days after sowing (ASD) and at 25 days after sowing (25DAS). At 60 days after seeding, plant heights of barley and hairy vetch were higher in 15DBS treatment than those in other treatments. Biomass of barley was higher in the order of 15DBS (50.2g plant^-1) > ASD (49.8g plant^-1) > 25DAS (48.5g plant^-1) > control treatment (37.5g plant^-1). Biomass of hairy vetch in 15DBS treatment was higher than that in other treatments. Nutrient contents of barley and hairy vetch were not different regardless of LPM application times. On the other hand, the amounts of nutrients uptake in 15DBS treatment were higher than those in other treatments. Therefore, in considering growth status and nutrient contributions of GMC, the optimum application time of LPM was 15DBS.

• Journal of Ecology and Environment
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• v.42 no.4
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• pp.259-264
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• 2018

Background: Revegetating landfills can be a challenging task as the reclaimed soils are typically dry and have low nutrient content. Therefore, selecting suitable plant species is important for initial revegetation. The issue with current practices (in Korea) is that alien plant species have been typically selected for revegetation projects. In this context, this study selects and tests a set of native plant species for landfill revegetation, accompanied by the assessment of the landfill soils. Results: The soil of the landfill (landfill location) was in a very poor condition with high bulk density and low organic matter and nutrient contents. Among 10 tested species, only Brassica campestris showed high coverage and a sufficient number of individuals in study quadrats sown with seeds. Results suggest that plant species with heavy seeds are the only ones that can adapt to the environment of a typical landfill due to the site's aridity and low nutrient content. The reason is due to such species' superior wind resistance and the capacity to provide sufficient energy for the initial growth of the plants for survival in such landfill environment. Conclusions: This study recommends selecting plant species (1) with arid-adapted features and (2) whose seed weight is sufficiently heavy for survival at landfills or areas with a similar condition for future revegetation.

• Journal of Environmental Science International
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• v.22 no.12
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• pp.1643-1650
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• 2013

This study investigated water quality of effluents and stream from the sewage treatment plants located at Gumi Complex 4, Gumi, and Wonpyeong in Gumi. Downstream region was found to increase the concentration of nutrients for sewage treatment plant effluent. Both phosphorus and nitrogen were accounted most as soluble form. In particular, the high ratio of dissolved effluent of sewage treatment plants were investigated. In the streams, Phosphorus concentration was high during rainy season and nitrogen concentration was high in the dry season. Sewage treatment plant effluent was relatively less microbial activity and nutrient concentrations were higher in the winter. TN/TP ratio was the highest in the upstream region and the lowest in the sewage treatment plant effluent. The effect of the nutrient matter from a discharge of a sewage treatment plant on rivers varied depending on the size of the river and the treatment plant. However, the influence of the concentration was greater than that of flowrate. Sewage treatment plant effluent loads phosphorus, nitrogen accounted for 8% and 6% respectively at the point N3 of the Nakdong river.