• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.5
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• pp.153-162
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• 2001

A study was carried out to investigate the water balance and losses of nutrients at a paddy plot located at the southern Korea. The observed amount of precipitation, irrigation, runoff, evapotranspiration and percolation for the experimental paddy plot during cropping period were 1,030, 566, 701, 551. and 310 mm for 1999 and 1.214, 413, 710, 682, and 234 mm for 2000 year, respectively. The measured input quantities of N and P into the paddy field during cropping period were 122 to 140 kg N $ha^-1$ and 29 to 30 kg $P_2O_5$ kg $ha^-1$ by chemical fertilizer, 20 to 28 kg N $ha^-1$ and 0.35 to 0.36 kg P $ha^-1$ by precipitation, and 26 to 35 kg N $ha^-1$ and 0.57 to 0.72 kg P$ha^-1$ by irrigation water. respectively. The output amounts of N and P from paddy field were measured as follows. They were 48 to 52 kg N $ha^-1$ and 1.1 to 1.6 kg P $ha^-1$by runoff water, and 9 to 12 kg N $ha^-1$ and 0.04 to 0.05 kg $ha^-1$ by percolation water. When the runoff losses of nutrients were compared to applied chemical fertilizer. it was found that 34.3 % to 42.6 % of nitrogen lost via runoff while runoff losses of phosphorus account for 3.8 % to 5.3 % of the total applied amount. When the ratio was calculated between nutrients losses by percolation water and the applied of chemical fertilizer, two year results showed 6.4 % to 9.8 % for the nitrogen and 0.1% to 0.2% phosphorus, respectively.

• Journal of Forest and Environmental Science
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• v.32 no.3
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• pp.280-290
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• 2016

Stem diameter variability is an essential inventory result that provides useful information in forest management decisions. Little has been done to explore the modelling potentials of standard deviation (SDD) and coefficient of variation (CVD) of diameter at breast height (dbh). This study, therefore, was aimed at developing and testing models for predicting SDD and CVD in stands of Pinus caribaea Morelet (pine) in south west Nigeria. Sixty temporary sample plots of size $20m{\times}20m$, ranging between 15 and 37 years were sampled, covering the entire range of pine in south west Nigeria. The dbh (cm), total and merchantable heights (m), number of stems and age of trees were measured within each plot. Basal area ($m^2$), site index (m), relative spacing and percentile positions of dbh at $24^{th}$, $63^{rd}$, $76^{th}$ and $93^{rd}$ (i.e. $P_{24}$, $P_{63}$, $P_{76}$ and $P_{93}$) were computed from measured variables for each plot. Linear mixed model (LMM) was used to test the effects of locations (fixed) and plots (random). Six candidate models (3 for SDD and 3 for CVD), using three categories of explanatory variables (i.e. (i) only stand size measures, (ii) distribution measures, and (iii) combination of i and ii). The best model was chosen based on smaller relative standard error (RSE), prediction residual sum of squares (PRESS), corrected Akaike Information Criterion ($AIC_c$) and larger coefficient of determination ($R^2$). The results of the LMM indicated that location and plot effects were not significant. The CVD and SDD models having only measures of percentiles (i.e. $P_{24}$ and $P_{93}$) as predictors produced better predictions than others. However, CVD model produced the overall best predictions, because of the lower RSE and stability in measuring variability across different stand developments. The results demonstrate the potentials of CVD in modelling stem diameter variability in relationship with percentiles variables.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.59-61
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• 2005

In Korea, hundreds of abandoned and closed coal and metallic mines are present in the steep mountain valleys due to the depression of the mining industry since the late 1980s. From these mines, enormous amounts of coal waste were dumped on the slopes, which causes sedimentation and acid mine drainage (AMD) to be discharged directly into streams causing detrimental effects on soil and water environments. A limestone slurry by-product (lime cake) is produced from the Solvay process in manufacturing soda ash. It has very fine particles, low hydraulic conductivities ($10^{-8}{\sim}10^{-9}cm/sec$), high pH, high EC due to the presence of CaO, MgO and $CaCl_2$ as major components, and traces of heavy metals. Due to these properties, it has potential to be used as a neutralizer for acid-producing materials. A field plot experiment was used to test the application of lime cake for reclaiming coal wastes. Each plot was 20 x 5 m (L x W) in size on a 56% slope. Treatments included a control (waste only), calcite ($CaCO_3$), and lime cake. The lime requirement (LR) for the coal waste to pH 7.0 was determined and treatments consisted of adding 100%, 50%, and 25% of the LR. The lime cake and calcite were also applied in either a layer between the coal waste and topsoil or mixed into the topsoil and coal waste. Each plot was hydroseeded with grasses and planted with trees. In each plot, surface runoff and subsurface water were collected. The lime cake treatments increased the pH of coal waste from 3.5 to 6, and neutralized the pH of the runoff and leachate of the coal waste from 4.3 to 6.7.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.431-438
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• 1983

Experiments were conducted to know the effects of 15 years successive application of fertilizers and organic matters on the soil properties, plant growth and yield of rice. Application of fertilizers and organic matters for 15 years in same plots were increased soil pH, OM, and CEC, but decreased $SiO_2$ and Ca content in paddy soil. Organic matter application for 15 years was increased OM about 0.5% compare to non-applied plot. Particulary lime application was increased soil pH, $SiO_2$, Ca and CEC in paddy soil. NPK+compost and NPK+straw application were increased number of panicles and number of spikelets per unit area, but decreased ripening ratio compare to NPK applied plot. Average grain yield for 15 years in the non-fertilized, -N, -P, -K, NPK+compost, NPK+straw and NPK+lime applied plot was 47, 51, 88, 95, 113, 117, and 106% of yield conpare to NPK applied plot, respectively.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.78-82
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• 2005

Three of the genus Pseudomonas (P. aeruginosa, P. putida, P. syringae) show highly different phenotypic characteristics among them. Two of the three members are pathogenic and the other is non-pathogenic. Comparative analyses of the complete genomes can elucidate the genomic similarities and differences among them. We analyzed the three genomes and the genes of them to reveal the degree of conservation of chromosomes and similarity of the genes. The 2-dimensional dot plot between the pathogenic P. aeruginosa and non-pathogenic P. putida shared higher portion of the nucleotide sequences than other two combinations. Comparison of the nucleotide compositions by calculating the genome-scale plot of G+C contents and GC skew showed the variation of location. Comparison of the metabolic capabilities using the functional classification of KEGG orthology revealed that the differences in the number of genes for the specific functional categories resulted in the phenotypic differences. Finally combination of the analyses using the protein homologs supported the evolutionary distance of the P. putida obtained from other genome-scale comparisons.

• Korean Journal of Environmental Agriculture
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• v.22 no.1
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• pp.26-35
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• 2003

An investigation was carried out to evaluate the effects of pebble size on the small-scale sewage treatment apparatus by natural purification method that consisted of aerobic and anaerobic plot. pH and EC in both plots varied minimally regardless of pebble size. DO in aerobic plot increased as the pebble size decreased. That in the anaerobic plot was slightly less in comparison with that of the aerobic plot but varied minimally, $2.4{\sim}5.1\;mg/L$ regardless of pebble size. Under all experimental conditions, removals of BOD, COD and turbidity in anaerobic plot were more than 98, 91 and 98, 98% respectively. Removals of T-N and T-P increased as pebble size decreased. Under all experimental conditions, removals of T-N and T-P in anaerobic plot were about $45{\sim}59$ and $480{\sim}96%$, respectively. Judging from the above results, it should be considered that the optimum pebble size and pebble permeability in both plot was $2{\sim}4$ and $0.1{\sim}4\;mm$, respectively.

• Korean Journal of Medicinal Crop Science
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• v.23 no.4
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• pp.277-283
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• 2015

This study was conducted to investigate the selected chemical properties of soils in Saururus chinensis Baill (Chinese lizard's tail) cultivation fields to provide optimal fertilizer application rates and to examine the growth and pharmaco-consitituents of Saururus chinensis Baill as influenced by different amounts of nitrogen (N) fertilizer applications. Based on the results of selected soil chemical properties in 37 cultivation sites of the plant, soil pH, organic matter content, and exchangeable $K^{+}$ concentration were lower than optimal values for cultivating general medicinal crops even though relatively high standard deviations were found in some of the values. At the harvesting stage of the plant aerial parts, soil pH, electrical conductivity (EC), available $P_2O_5$, and exchangeable $Ca^{2+}$, $Mg^{2+}$, $Na^{+}$ decreased as comparing with those before transplanting the plant, whereas the concentration of exchangeable $K^{+}$ increased in the plot treated with N 100% and compost. Fresh weight of the plant aerial parts were highest, 492.5kg/10, in the N 100% treatment plot. Correlation equation between N levels treated (X) and yield of the plant aerial parts (Y) presented as $Y=-2.1609X^2+30.082X+344.12$($R^2= 0.7113$) and the optimal rate of N fertilizer application for the plant was 6.6kg/10a. Carbon concentrations in the plant were not different among the different N levels applied. N and K concentrations in the plant were highest in the plot of N 100% with compost applications, the highest P concentration was in N 100% plot, and the highest Ca and S concentrations were in N 200% plot. Quercetin and quercitrin were highest in the N 150% plot and tannin was highest in N 100% or N 100% with compost application plot.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.480-488
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• 2016

Soil microbes are widely well known to play an important role for sustainable agriculture in terms of crop healthy cultivation and environmental conservation. In this context, the distributional characteristics of soil microbes according to cropping systems were investigated under rice (R)-rice (R), rice (R)-barley (B)-rice (R), and soybean (S)-barley (B)-soybean (S) cropping condition to get basic informations for sustainable agriculture, where barley was grown for winter, in mid-mountainous loam paddy located at the altitude of 285 m above sea level in Sangju area from 2014 to 2015. Estimating from microbial communities by fatty acid methyl ester (FAME) method, a total biomass of bacteria, actinomycetes, and fungi in R-B-R plot was 37% and 40% higher than that in S-B-S and R-R plots, respectively (p < 0.05). In especial, bacteria and fungi were more in R-B-R plot than those in any other ones. B. japonicum, AMF, and mesophilic Bacillus sp. were also greater in S-B-S plot than those. In the community distribution, however, bacteria and actinomycetes showed comparatively high values in S-B-S plot relative to either R-R or R-B-R plot including rice, in which fungi outstanding. In the correlation between microbial biomass and soil properties changed by the cropping, bacteria was positively correlated with C:N ratio; actinomycetes with exchangeable Ca; fungi with available $P_2O_5$ (p < 0.05). While these microbes showed negative response to water stable aggregates of soil.

• Plant Resources
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• v.3 no.3
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• pp.200-205
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• 2000

This study selects Sunwol local group, Gusang local group and Yongjun local group to examine the appropriate amount of applied fertilizer in cultivating the double crop seed of Alisma plantago by transplantation in the southern area, improve and complements the double cropping techniques and contribute to stable production. While the plant height is 45,47 and 49cm and the number of leaves is 11.7, 12.5 and 14.4 at non-fertilizing plot, the plant height is 67, 72 and 75cm and the number of leaves is 15.8, 17.2 and 19.3 at all fertilizing plot and their growth is active and in the character of plant height and the number of leaves, especially in the groove of N-P$_{2}$O$_{5}$-K$_{2}$O= 30-15-45kg/10a, the mean plant height of Sunwol is 75cm and mean number of its leaves is 19.3, the mean plant height and number of leaves in Gusang are 72cm and 17.2 respectively and those of Yongjun are 67cm and 15.8 respectively. While the number of floral axis is 1,2 in non-fertilizing plot, that of the whole varieties in all fertilizing plot is 3, 4, 5 and the mean floral axis of Sunwol is N-P$_{2}$O$_{5}$-K$_{2}$O = 10-5-15, 20-10-30, 30-15-45 kg/10a and 18-0-18 of complex fertilizer and 21-17-17kg/10a and it is small in all fertilizing plot. The yield of dry root per 10a is high in all fertilizing grooves and especially in the groove of N-P$_{2}$O$_{5}$-K$_{2}$O = 30-15-45 kg/10a, it is 372.6kg, in the groove of 18-0-18kg/10a using complex fertilizer, it is 389.1kg and in that of 21-17-17kg/10a, it is 376.7kg.6.7kg.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.2
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• pp.49-60
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• 2014

This study was conducted to evaluate the effect of forest fire on natural distribution and regeneration of Pinus densiflora Sieb. & Zucc. in Goseong, Gangwon province, Korea. After 13 years of the last forest fire in 2000, five investigation plots ($10m{\times}10m$) in each of rocky land and ridge, the well-known location as a favorite site for natural distribution of P. densiflora, were set to investigate stand characteristic and soil environment including physico-chemical properties and moisture contents of soil. Also, five investigation plots in slope area were set and investigated as well. The concentration of organic matter, total nitrogen, and exchangeable nutrients ($K^+$, $Ca^{2+}$, $Mg^{2+}$) were highest in the slope while the soil in the rocky land showed the lowest concentration of organic matter, total nitrogen, available $P_2O_5$, and exchangeable nutrients ($K^+$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$). The soil in the slope only showed higher concentration of total nitrogen, $K^+$ and $Ca^{2+}$ than the unburned area in Goseong. Mean soil moisture contents in the rocky land (5.77%) were lowest while the slope (15.78%) and the ridge (15.27%) showed almost three times as much than the rocky land. P. densiflora was dominant in the rocky land and Quercus spp. were dominant in the ridge and slope. The average proportion of P. densiflora was highest in rocky land (58.4%, 14.6 trees per plot) followed by the ridge (25.2%, 7.8 trees per plot) and the slope (11.3%, 3.4 trees per plot) while the average height of P. densiflora was highest in slope (277cm) followed by the ridge and the rocky land. The height and crown width of Quercus spp. were higher than P. densiflora in the every plot. The results suggest that P. densiflora may be able to naturally regenerate and survive in the rocky land after the fire while P. densiflora in the ridge and the slope are suppressed by Quercus spp.