• Korean Journal of Environmental Agriculture
• /
• v.25 no.4
• /
• pp.289-296
• /
• 2006

Various drying conditions, temperatures (40 to $80^{\circ}C$) and durations (overnight to 72 hrs), for the particulate organic matter (POM) fraction after wet-sieving size fractionation have been applied for determination of POM contents in the weight loss-on-ignition method. In this study, we investigated the optimum drying condition for POM fraction in quantification of POM and/or mineral-associated organic matter (MOM; usually indirectly estimated). The influence of the drying conditions on quantifying POM was dependent upon soil properties, especially the amount of soil organic components. In relatively high organic soils (total carbon > 40 g/kg in this study), the POM values were significantly higher (overestimated) with drying at $55^{\circ}C$ than those values at $105^{\circ}C$, which were, for example, 173.2 and 137.3 mg/kg, respectively, in a soil studied. However, drying at $55^{\circ}C$ for longer than 48 hrs of periods produced consistent POM values even though the values were much higher than those at $105^{\circ}C$. Thus, indirect estimates of MOM (MOM = SOM-POM) also tended to be significantly impacted by the dry conditions. Therefore, we suggest POM fractions should be dried at $105^{\circ}C$ for 24 hrs as determining POM and MOM contents. If the POM traction is needed to be dried at a lower temperature (e.g. $55^{\circ}C$) with a specific reason, at least 48 hrs of drying period is necessary to obtain consistent POM values, and a moisture correction factor should be determined to adjust the values back to a $105^{\circ}C$ weight basis.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.16 no.2
• /
• pp.155-160
• /
• 1996

Spring sown oat crops were grown during early March to late June in 1993~1994. The crops were harvested at different stage of maturity to determine the yield performance, chemical components and net energy value of the plants for silage utilization. The pattern of dry matter accumulation, absolute growth rate(Abs. GR), leaf weight ratio(LWR), stalk diameter(SD) and other growth parameters were analysed to evaluate the suitability of the plant materials for ensiling. The effect5 of wilting treatment and formic acid addition on the quality of silage was also disscused during the experiments. Spring sown oat crops was evaluated as a suitable materials for whole plant silage making. The best qualitative oat silage was obtained at the stage of soti dough to hard dough, when the plant reached 32.2~35.7% in dry matter concentration. Spring sown oat produced 9.43 ton in DM basis, 5.79 ton in TDN and 57.550 MJ-NEL/ha in net energy lactation. Early harvesting of the oat corps needed wilting treatment of the material before ensiling. Under pre-witing treatment (1/2 day) and formic acid addition(0.3%) silage quality point of oat crops harvested at the bloom stage was improved from 58 to 84 point.

• Korean Journal of Plant Resources
• /
• v.12 no.4
• /
• pp.269-275
• /
• 1999

For the purpose of sweet potato varietal improvement, yulmi, shinyulmi, gunmi, hongmi, and seonmi, whose source and sink are different, were cultivated at different planting densities, and then defoliation at initial stage of tuberous root weight increase on the relation of source and sink was observed as follows. The response of stem and leaf and tuberous root weight by planting density and defoliation rate of sweet potato varieties was different. Stem and leaf weight per m$^2$ increased along with dense planting by the following order; shinyulmi> seonmi> hongmi> gunmi> yulmi. Tuberous root number per m$^2$ was the most at 75$\times$20cm planting density, showing seonmi the most number. The number of stem and leaf and tuberous root increased along with the lowered rate of defoliation. In case of 75$\times$10cm and 75$\times$20cm planting density, tuberous root weight increased by increase of stem and leaf weight up to 50% defoliation and the difference of stem and leaf and tuberous root number was low as defoliation rate increases. The tuberous root and total dry weight matter was the most at 75$\times$20cm planting density. The increase and decrease of source synchronized with those of sink at 75$\times$10cm and 75$\times$20cm, however the relationship occurred less at 75$\times$30cm.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.45 no.1
• /
• pp.26-31
• /
• 2000

This study was carried out to obtain the basic information for breeding cold-tolerant rice varieties with high yield-productivity through wide crosses between indica and japonica rice. Genetic analysis was conducted using 55 F$_1$s obtained from half-diallel crosses among eleven cultivars of various origin including indica and japonica rice. Screening for cold tolerance was done with cold-water irrigation after transplanting until ripening stage. Both general combining ability (GCA) and specific combining ability (SCA) effects were highly significant in all characters associated with dry matter accumulation at 30 and 50days after cold-water irrigation (DAC). The variance of GCA was much larger than that of SCA in plant height, shoot dry weight per plant (DWP), crop growth rate (CGR) and cold-water response index (CRI) of these characters except CRI of shoot dry weight per plant. The DWP, CGR and CRI of these characters of Gaochan 102, Tong88-7 and TR22183 were markedly higher than those of the others. GCA effects of these varieties on DWP, CGR and their CRI were also higher than those of the others, indicating that they are useful as promising parents for breeding cold-tolerant varieties. Analysis of genetic parameters for 11$\times$11 half-diallel F$_1$s revealed that inter-locus gene interaction were concerned in the expression of plant height at 50 DAC, CRI of DWP at 50 DAC, and CRI of CGR, and that intra-locus gene interaction for plant height and the other characters were partial dominance and over-dominance, respectively. Narrow-sense heritability (h$^2$$_{N}$) was the highest in plant height as 0.729, and the lowest in CRI of DWP at 30 DAC as 0.048, suggesting that selection for cold tolerance will be quite effective in case that the selection criterion is the performance itself.f.

• The Korean Journal of Ecology
• /
• v.9 no.1
• /
• pp.73-78
• /
• 1986

The effects of density and soil nutrient regime on competition between individuals in pure and mixed populations of two annuals. Chenopodium album and Digitaria sanguinalis were investigated at the level of enegy allocation. Seedling emergence of two species was extremely high (>90%) in both pure and mixed culture irrespective of the density and nutrient regime, but percentage of seedling establishment or fertile plant became gradually low with increasing density owing to 'self-thinning'. The mean plant dry weight was significantly reduced with increasing density and decreasing soil fertility. The dry matter production of D. sanguinalis in mixture was markedly greater than in pure culture under medium and high density. Also, as considered the number of seed production as reproductive allocation, relationship between them and the number of seed production per plant showed a similar tendency. Therefore, these results indicated that D. sanguinalis had a greater competitive advantage than C. album and energy allocations to variious organs were regulated by plastic response rather than determined genetically.

• Korean Journal of Agricultural Science
• /
• v.6 no.2
• /
• pp.105-111
• /
• 1979

This experiment was carried out to define the affinity of alfalfa varieties to nodule bacteria and the effects of nodule bacteria on the growth of alfalfa varieties. The results obtained are summarized as follows; 1. The ability of nodule formation on the roots of alfalfa was significantly different among the strains of nodule bacteria, Rhizobium meliloti SU 47 formed nodules on the roots of two alfalfa varieties, Luna and Von arnims altd bost. Nodules were not formed at the roots of all varieties by inoculation of Rhizobium meliloti M1 but a lot of nodules were formed at the roots of all varieties by inoculation of Rhizobium meliloti M14. 2. When the Rhizobium meliloti M14 was inoculated in the media, the largest numbers of nodules were formed on the roots of alfalfa cultivar Franks hangmeiler and the least numbers of nodules were formed on the roots of cultivar Elga. 3. The plant height and the dry matter weight of all alfalfa cultivars were significantly increased by inoculation of Rhizobium meliloti M14, and also those were increased by applying nitrogen, but when the alfalfa cultivars were grown on the media inoculated Rhizobium M1, the plant height and the dry matter weight of alfalfas were not increased and they were same as those grown on check media. 4. The significant correlation were not detected between the number of nodules formed on the, roots of alfalfa cultivars and the plant height or the dry matter weight of alfalfa cultivars.

• Journal of Plant Biology
• /
• v.14 no.4
• /
• pp.19-26
• /
• 1971

The sample stand of Pinus rigida plantation was chosen from those at the Choongnam Forest Experiment Station, Choongnam. The diameter at breast height (D) and the height of tree (H) of each tree in the sample plot of 200$m^2$ were measured yearly a from 1967 through 1969. The stand was 12.7-13.4cm in mean diameter and had a stand density of 2,150 trees per ha. The trunk, branches and leaves of each sample tree were separately weighed according to the stratified clip technique. The allometric relation between D2H and dry weight of trunk (Ws), branches (Wb) and leaves (Wl) were approximated by $$W_s=0.05917 (D^2H)^{0.837}$$ $$W_0=0.00655 (D^2H)^{0.989 }$$ $$W_l=0.04466(D^2H)^{0.690}$$ From the above, the standing crops in the sample stand was estimated to be as much as 76.7, 81.7 and 88.2 tons of dry matter, above ground, per ha in 1967, 1968 and 1969, respectively. Annual net production, as the sum of the biomass newly produced during one year, was estimated at 4.97-5.47 tons per ha per year. The respiratory and the photosynthetic rate deduced from theoretical calculations were 0.045 and 0.74kg of dry matter per kg per year. Tentative estimate of annual respiratory loss was made and annual gross production was roughly estimated at 4.4-4.7 and 10.7-12.9 tons of dry matter per ha per year. The ratio of respiratory loss to gross production was approximately 36-41:1.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.4 no.3
• /
• pp.206-211
• /
• 1984

The influence of fertilizer on the growth characteristics in Korean lawn grass was studied from June through October in a experiment. The results were as follows: 1. Maximum dry matter weight of Korean lawn grass was achieved in early in early August when it was $64.3g/m^2$ without fertilizer and $157.9g/m^2$ with fertilizer. On the other hand, the dry matter weight of whole plant including Korean lawn grass reached the maximum in late September, which was late, to some extent, compared with that if pure Korean lawn grass, presumably associated with seed maturing period of $C_4$ type plants. 2. Notable positive effect on leaf blade and non-leaf part weight in Korean lawn grass was also detected. However, the rate of dry matter occupied by non-leaf part was markedly increased by fertilizer application. 3. The dry matter portion occupied by Korean lawn grass the in total dry matter weight of whole plant was significantly decreased as time went by, particularly in case of fertilizer application. 4. Fertilizer, which might imply an increased potential of tiller numbers according to fertilizer. 5. In general, the seasonal change pattern of the rhizome of Korean lawn grass coincided with that of the aboveground organs: Its maximum dry matter weight achieved from late August to early September was $194.2g/m^2$ with nil fertilizer, and, with fertilizer, $259.7g/m^2$, of which figures were equivalent to be increased to 33.7%, compared to that with nil fertilizer. Applying fertilizer increased the weight of root: The highest values were $36.7g/m^2$ with nil fertilizer and $80.9g/m^2$ with fertilizer.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.13 no.4
• /
• pp.294-299
• /
• 1993

This expeiment was conducted to evaluate the effect of the different planting and harvest date on dry matter yield and feed value of forage oat (Avena sativa L.). Seeds were planted on September 1 (first), September 11 (second) and September 21 (third planting date) by hand between rows 30cm and harvest were achieved on November 7 (first) and November 19 (second harvest date) 1992. 1. The plant height was influenced by planting and harvest date. the first planting date showed the tallest plant height. 2. Dry matter (DM) content decreased with delaying planting date from first to third planting date, DM varied from 15.1 to 13.5% and increased with delaying harvest date from first to second harvest date at the same planting date. 3. Leaf weight ratio increased delaying planting date from first to third planting date, varied from 52 to 77%. 4. The content of crude protein increased with delaying planting date from first to third planting date, varied from 14.3 to 25.4% NDF and ADF contents were influenced by planting date and harvest date, it was decreased with delaying planting date. 5. The dry matter yields per ha decreased with delaying planting date: it was 6, 705, 5, 520, and 2, 315 kg at first, second and third planting date, respectively. Significant difference has been obtained among planting date(P<.01). The dry matter yields increased with delaying harvest: it was 4, 027 kg at first and 5, 667 kg at second harvest(P<.01). 6. According to the results obtained from this study. it is suggested that planting date on September 1 and harvest date on November 19 would be recomendable for fall oat forage production.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.40 no.2
• /
• pp.130-137
• /
• 2012

This research evaluated the effectiveness of organic matter ratios in substrate and mulching materials under mn-irrigated condition green roofs by measuring the effects on growth of Liatris spicata. Four mulching materials were installed, i. e. nun-mulched control(CON), volcanic ash soils(VAS), non-woven black fabric mat(NBM) and pine bark(PAK). Three levels of organic maller volume percentage in an amended soil were evaluated, amended soil: organic matter=100:0($A_1O_0$), amended soil: organic matter=80:20($A_4O_1$) and amended soil: organic matter=50:50($A_1O_1$). Plant height, number of leaves, diameter of flower stalk, number of florets, chlorophyll contents, shoot fresh and dry weight were recorded from April to September, 2010, and survival rate was examined on May 2011 of the following year. In the $A_1O_0$, the number of leaves, number of florets and chlorophyll contents were higher in Liatris spicata grown on NBM than other mulching treatments. Especially, plant height, shoot fresh and dry weight were significantly higher. However, it resulted the lowest survival rate than other mulching treatments. 2. In the $A_4O_1$, the plant height, number of leaves, number of florets, shoot fresh and dry weight were higher than other mulching treatments, but there was no significant difference except for the plant height of Liatris spicata grown on NBM. The survival rate was decreased by 40~60%, compared with $A_1O_0$, after overwintering. 3. In the $A_1O_1$, the plant height, number of leaves, diameter of flower stalk, number of florets, chlorophyll contents, shoot fresh and dry weight were slightly higher than other mulching treatments, but there was no significant difference from Liatris spicata grown on NBM and VAS. The survival rate was observed by 0% over all mulching treatments after overwintering. Therefore, the non-woven black fabric mat(NBM) promoted the Liatris spicata's growth and flowering compared with other mulching treatments. However, the survival rate was decreased significantly, and the organic matter ratios were increased after overwintering under non-irrigated green roofs.