• 아시안잔디학회지
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• 제5권1호
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• pp.33-39
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• 1991

This experiment was carried out in order to study the changes of morphological characters of growth and thatch accumulation in perennial ryegrass as affected by the different levels of soil compaction and coring depth. Soil compactions were treated with 10, 20, 30 and 40kg power roller and artificial core depth were 2.5, 5.0, 7.5 and 10.0cm under the ground, respectively. And, artificial core space were fixed 84.5% in all soil compaction levels. The results obtained were summarized as follows: 1. Relationship between number of tillers and root weight was positive significant difference for soil compaction levels. 2. Relationships between shoot dry weight and thatch weight, and number of tillers were positively significant difference for artificial core depths. It may indicate that thatch accumulation depend on the growth of shoot, and increase of shoot dry weight as growth progressed may due to increase of number of tillers, respectively. 3. Soil compaction level of 20kg was greatly influenced on the growth of shoot in all artificial soil depths. Thus, shoot dry weight and number of tillers were obtained the highest value, but thatch and root weight were obtained the lowest values at the soil compaction level of 20kg. It was suggested that soil compaction of 20kg is very suitable rolling factor for turf maintenance. 4. Thatch weight was positively significant difference for the interaction of soil compaction levelXcoring depth.5. Thatch weight was positive significant correlated with root weight, and negative significant correlated with number of tillers by increase of soil compaction levels.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.492-497
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• 2008

The objective of this research is an investigation of engineering properties of weathered granite soil mixed with Phosphogypsum and recycled EPS beads as an light-weighted soil. A series of geotechnical laboratory tests including physical index test, compaction test, CBR test and direct shear test were performed for various mixing ratios. Based on the laboratory test results, it was found that the maximum dry unit weight of the light weight soil ranges $1.46{\sim}1.61g/cm^3$ and the maximum dry unit weight decreases about 11~19.3% with the increase of amount of the recycled EPS beads and the optimum moisture content increase. Since the CBR values of the light weight soil ranges 10.4~18.4%, the light weight soil mixed with Phosphogypsum and recycled EPS beads can be used as a light weight backfill material on the soft soil.

• 한국농공학회논문집
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• 제62권1호
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• pp.95-104
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• 2020

The purpose of this study is to develop a pipe type soil sampler that can easily collect soil cross section servey and soil samples to conduct ecological environment surveys while minimizing ecological disturbance in the area subject to soil survey. Furthermore, this study develop the exponential type estimation specific weight formula (ESWF) that uses pipe type soil sampler to easily carry out soil cross section survey and soil sample while estimating the specific weight of the area using water content and soil sample length variation ratio (SLVRs) and to obtain apparent specific gravity, hardness, and max. porosity which are used as growth of corps and ecological environment index. The calibration results of ESWF showed a high degree of significance, with NSE for actual specific weight (γ₀) and calibration estimation specific weight (γ_ec) 0.95, R² for 0.954, and RMSE for 0.051. The verification results of ESWF showed a high significance, with NSE for actual specific weight (γ₀) and verification estimation specific weight (γ_ev) 0.881, R² for 0.978, and RMSE for 0.055.

• 한국미생물·생명공학회지
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• 제42권1호
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• pp.32-40
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• 2014

본 연구에서는 도심 학교 운동장(soil A)과 화단(soil B, C, & D)에서 채취한 토양의 잠재적인 메탄 산화 및 생성능을 평가하였다. 토양 원시료 중 메탄 산화균 수를 정량 분석한 결과, 운동장 토양(soil A)는 $6.1{\times}10^3$ gene copy number/g dry weight soil이었으나, 화단 토양(soil B~D)는 $1.6-1.9{\times}10^5$ gene copy number/g dry weight soil이었다. 토양을 넣은 혈청병에 메탄 가스를 주입하여 잠재 메탄 산화능을 평가한 결과, 운동장 토양은 다른 토양보다 메탄을 산화하기까지 긴 유도기를 보였으나, 유도기 이후에는 화단 토양과 거의 유사한 메탄 산화능을 나타냈다. 또한 운동장 토양의 메탄 산화균 수는 $2.3{\times}10^7$ gene copy number/g dry weight soil까지 증가하여 화단 토양의 메탄 산화균 수($1.2-2.8{\times}10^8$ gene copy number/g dry weight soil)과 유의적 차이를 보이지 않았다. 교정에서 채취한 토양의 메탄 생성 거동도 메탄 산화와 유사한 패턴을 보였다. 토양 원시료의 메탄 생성균 수는 화단 토양($1.3-3.4{\times}10^7$ gene copy number/g dry weight soil)에 비해 운동장 토양($1.7{\times}10^5$ gene copy number/g dry weight soil)이 훨씬 적었다. 그러나 토양에 유기물을 첨가한 후 메탄 생성 현상이 발휘된 후에는 메탄 생성 균수는 운동장 토양과 화단토양 모두 $10^7$ gene copy number/g dry weight soil 수준이었다. 본 연구를 통해 도심 교정에서 채취한 네 종류의 토양은 모두 메탄 산화균 및 생성균을 가지고 있으며, 메탄 산화와 생성에 적합한 조건이 되면, 메탄 산화균 및 생성균의 개체군이 증가하여 메탄을 산화하거나 생성할 수 있는 잠재력을 지니고 있음을 알 수 있었다.

• 한국토양비료학회지
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• 제45권1호
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• pp.93-97
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• 2012

This study was conducted to evaluate the efficiency of various inorganic and organic materials to improve physical properties of soil. Saline sodic soil (saturation percentage = 40.36%, $EC_e=5.15dS\;m^{-1}$, $pH_s=8.70$, $SAR=18.84(m\;mol\;L^{-1})^{1/2}$, bulk density =$1.49Mg\;m^{-3}$) was collected, brought to wire house and filled in pots after laboratory analysis for various parameters. Different sources of organic nutrients like farm manure (FM), press mud, compost, poultry manure and sesbania green manure were analyzed for their chemical composition. The experiment comprised of 12 treatments replicated thrice; $T_1$: control (recommended NPK), $T_2:{\frac{1}{2}}$ recommended NPK, $T_3$: FM at 1.5% by soil weight, $T_4$: pressmud at 1.5% by soil weight, $T_5$: compost at 1.5% by soil weight, $T_6$: poultry manure at 1.5% by soil weight, $T_7$: sesbania green manure at 1.5% by soil weight, $T_8:T_2$ + FM at 0.75% by soil weight, $T_9:T_2$ + pressmud at 0.75% by soil weight, $T_{10}:T_2$ + compost at 0.75% by soil weight, $T_{11}:T_2$ + poultry manure at 0.75% by soil weight, $T_{12}:T_2$ + sesbania green manure at 0.75% by soil weight. These treatments were applied using completely randomized (CR) design and appropriate time was given to decompose these organic nutritional sources. Seeds of wheat cultivar Sahar-2006 were sown. After harvesting the wheat, soil samples were collected from each pot and analyzed for various physical properties like bulk density, porosity and saturation percentage. An improvement in physical properties (bulk density, porosity and saturation percentage) of soil was noticed with the application of various organic nutritional sources but role of compost alone ($T_5$) remained prominent.

• 한국초지조사료학회지
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• 제7권1호
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• pp.1-7
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• 1987

A pot experiment conducted to investigate the root elongation and weight of grasses, i.e. Orchardgrass, tall fescue and perennial ryegrass under the conditions adjusted pH of half vertical part of pot soil to seven levels from 2 to 8. 1. Root growth was drastically decreased as soil pH was lowed. 2. Higer the soil pH, longer the root length. Increase of soil pH to 6 increased the root length of orchardgrass, perennial ryegrass and tall fescue. 3. Regardless of grass species, most of roots distributed to the soil which adjusted pH from 6 to 7. 4. Dry weight of root was increased to pH 7 of soil in orchardgrass and perennial ryegrass and was 55 to 78% of production of pH 6 compared with soil pH 7. In case of tall fescue, dry root weight in the soil pH 7 was 69.8% of root weight growed in soil pH 6.

• 한국작물학회지
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• 제44권1호
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• pp.20-25
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• 1999

This experiment was conducted to elucidate the relation-ship between vertical distribution of rice roots and yield traits under field conditions. Eight IRRI's new plant type rices (NPTRs) were tested in a volcanic ash soil paddy field under dense (IO 10 cm) and common (20 20 cm) planting densities. These lines were evaluated to have more spikelet numbers per panicle (SNP), lower filled grain rate (FGR), and lower rough grain weight per hill (RGWH). In dense planting, rough grain weight per stem (RGWS) was increased due to heavier culm and leaf dry weight (CLDW), and both RGWS and CLDW were related with the percentage of root distribution (%RWI) in the 10~30 cm soil layer, while in common planting, RGWS was not closely related with CLDW. SNP was highly related with root dry weight (RDW) in the 0~10cm soil layer. FGR was mainly affected by ROW in the 10~30 cm soil layer under both planting densities. RGWS was positively correlated with top dry weight (TDW) and harvest index (HI), and TDW was positively correlated with RWI under common planting or %RWI under dense planting, and HI was positively correlated with RWI in the 10~30 cm soil layer only under dense planting. RGWS was closely related with root weight index by dry weight (RWI) in the 10~30 cm soil layer and %RWI in the 0~30 cm or 10~30 cm soil layer under dense planting, and with only RWI in the 10~30 cm soil layer under common planting. But RGWH showed the close positive relationship with RDW and RWI in the 10~30 cm soil layer under dense planting, while under common planting, it showed the close positive relationship with RWI and %RWI in the 10~30 cm soil layer or %RWI in the 0~30 cm soil layer. The deeper root system in rice, especially under dense planting, is important for high yield of NPTRs focusing on the increment of top mass production and harvest index.

• 한국환경복원기술학회지
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• 제26권5호
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• pp.47-56
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• 2023

The Quercus variabilis and Quercus dentata, which are said to be relatively drought tolerant among the important genus Quercus that represent deciduous broad-leaved forests in Korea. These two species are widely distributed worldwide in Korea, Japan and China (northern, central, western and eastern subtropical regions). This study compared the ecological niche breadth and overlap according to growth response in 4 soil moisture gradients for the two species and tried to reveal degree of competition and ecological niche characteristics. The ecological niche breadth was 0.977±0.020 for Q. variabilis and 0.979±0.014 for Q. dentata, the latter being slightly wider. And they were similar in 5 traits (stem length, leaf lamina length, leaf width length, stem weight, leaf petiole weight), Q. variabilis was more dominant in 4 traits (leaves number, stem diameter, leaf area, leaf petiole length), and Q. dentata was more dominant in 7 traits (root length, shoot length, plant weight, root weight, shoot weight, leaf weight, leaf petiole weight). The ecological niche overlap for soil moisture between the two species overlapped most in plant structure-related traits and least in photosynthetic organ-related traits such as petiole length. As a result of principal component analysis, degree of competition between the two species for soil moisture was more severe when the soil moisture condition was low than high. Among the measured traits that affect the two-dimensional distribution, 8 traits (Leaves number, Shoot length, Stem length, Plant weight, Root weight, Shoot weight, Stem weight, Leaves weight) were correlated with the factor 1, and 2 traits (Leaf width length, Leaf petiole weight) were correlated with the factor 2 (r>0.5). These results show that the ecological response of the two species to soil moisture is not a few traits involved, but several traits are involved simultaneously.

• 한국유기농업학회지
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• 제5권2호
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• pp.93-104
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• 1997

In order to investigate the growth response of grasses to chitosan solution amended soil were studied from the standpoint of estimating the growth stimulating adequate concentrations of chitosan solution amended soil in each grass. Three species in this experiment used were orchardgrass, tall fescue and reed canarygrass. Six different concentrations of chitosan solution amended soil were 0%(control), 0.01%, 0.05%, 0.1%, 0.5% and 1.0%, respectively. The resulte obtained were as follows ; 1. Leaf area(LA), dry weight of leaf(LW), dry weight of shoot(SHW), biological yield(BY), C/f ratio and T/R ratio were significantly different between species. 2. Growth stimulating effect by chitosan solution amended soil were found in plant length(PL) and T/R ratios of grasses. 3. Adequate concentrations of chitosan solution amended soil were different between species. The highest values of yield components and dry weight of plant parts were obtained at 0.01% in orchardgrass, 0,05% in reed canarygrass and 1.0% in tall fescue, respectively. 4. The growth response of grasses to chitosan solution amended soil were different between species. Thus, an increase in leaf area(LA) and dry weight of leaf(LW) by chitosan solution amended soil was mainly contributed to increase in dry weight of shoot(SHW) and biological yield(BY) in orchardgrass. Chitosan solution amended soil also stimulated growth of shoot and increased in biological yield(BY) in tall fescue. In reed canarygrass contributed to increase in C/F ratios. 5. Adequate concentrations of chitosan solution amended soil for an economical benefit of cultivation and dry matter production of grasses were ranged from 0.01% to 0.05% levels.

• 한국지반환경공학회 논문집
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• 제24권3호
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• pp.5-14
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• 2023

흙의 건조단위중량은 노건조된 흙의 무게를 측정하여 구할 수 있다. 한국산업표준(KS F)의 규정에 의해 110±5℃로 노건조된 흙은 공기 중에 노출 시 무게가 지속적으로 증가한다. 그러나, 노건조된 흙의 무게 측정 시간에 대한 규정이 없어 정확한 건조무게를 측정하는데 어려움이 있다. 본 연구에서는 무게 측정 시 나타나는 무게 특이점의 분석을 통해 건조무게를 쉽게 결정할 수 있는 방법을 제시하였다. 무게 특이점은 측정된 무게 중 가장 작은 값을 나타내며, 시료의 공기 중 수분 흡수의 영향이 최소화된 무게이다. 실험 과정에서 통계적 분석법을 이용하여 용기를 선택하였고, 광학현미경을 사용하여 시료의 사진을 제시하였다. 또한, 비접촉식 적외선 온도계를 사용하여 무게 특이점의 발생 온도를 측정하였다. 주문진 모래와 내성천 모래, 예천 화강풍화토, 제주도 모래, 사브카 모래, 울릉도 모래 등 6종류의 흙에 대하여 무게 특이점을 분석한 결과, 노건조된 각 시료의 무게 특이점은 무게 측정 후 8~27초 사이에서, 온도는 103.4~108.13℃의 범위에서 나타났다. 특이점의 무게 감소율은 흙 시료에 따라 0.0066~0.0085%로 나타났다.