• New & Renewable Energy
• /
• v.18 no.4
• /
• pp.70-78
• /
• 2022

To respond to global warming, there is an increasing interest in eco-friendly alternative energy sources. Therefore, unused forest biomass that has been neglected due to a lack of marketability is attracting attention. With the introduction of the "unused forest biomass certification system" in 2019, ways of determining quantity of unused forest biomass have steadily increased. However, there have been reported cases whereby unused forest biomass weighed more than the amount of harvested trees. It was found that it was possible that forest resources that can be used as round wood were mixed with unused forest biomass. In this context, this study aimed to estimate the amount of mixed round wood in the unused forest biomass supply. The relative expression of growing stock/ha versus the amount of final clearing/ha collected was modeled (y=1.490x-94.341, R²=0.861). As a result, it was found that round wood was mixed into the unused forest biomass, contributing to the disparity observed between the weighted forest biomass and the amount of trees harvested. In conclusion, proper declaration and certification procedures should be carried out for the use of forest resources and promoting unused forest biomass usage.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.5 no.6
• /
• pp.431-435
• /
• 2000

The goal of this research is to compare the metal binding characteristics of an anoxic selector activated sludge system and a conventional activated sludge system. Metal biosorption by biomass harvested from experimental systems was determined by a series of batch experiments. Heavy metals studied in this research were zinc, cadmium, and nickel. The sorption isotherm showed that the selector sludge had significantly higher sorption capacity than did the control sludge. Metal biosorption behavior closely followed a Freundlich isotherm model for equilibrium concentrations. ECP contents of biomass estimated by alkali extraction technique showed that ECP levels in the selector sludge significantly higher than that in the sludge harvested from the conventional system, indicating that the higher metal sorption capacity of selector sludge may be due to the selection of the ECP-producing bacteria (i.e., Zoogloea sp.) by the selector system.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.7
• /
• pp.956-959
• /
• 2001

Three perennial grasses, Napier (Pennisetum purpureum), Andropogan (Andropogan gayanus) and Para (Brachiria mutica), were grown at different hill heights dividing the hill slope into three regions (top, middle and bottom). The first two grasses gave the highest biomass yields (29.9 and 37.6 tonnes/ha/harvest, respectively) followed by Para (20.5 t/ha). No significant (p>0.05) changes in biomass yields of the grasses were found due to differences in hill heights. The grasses were harvested three times in the first year of cultivation. Maize and cowpea as sole crops or their intercrops were cultivated in the plain land and the intercrop gave the highest biomass yield (46.7 t/ha, p<0.05). The biomass produced was successfully ensiled in the underground pits at the hill tops.

• Journal of Environmental Science International
• /
• v.28 no.11
• /
• pp.927-933
• /
• 2019

A lipid-enriched strain of Botryococcus braunii (UTEX 572) was cultivated in a semi-batch aeration tank to enhance biomass as well as to develop intracellular lipids and fatty acids. A 30 day period of incubation produced 1.39 g/L of biomass and 0.31 g/L of total lipids in the biomass. The grown biomass was pre-treated using several methods to extract the total lipid content efficiently: ultrasonication was found to yield the highest percentage of lipids-namely 19.8% per biomass. Direct heating of biomass in an autoclave also showed better performance than when using only conventional solvent extraction. To enhance the biomass harvest and lipid extraction efficiency, coagulation and flocculation steps were added to the extraction process. It is noteworthy that not only the solvent type but also the solvent/biomass ratio greatly affected efficiency. In addition, the moisture content of the harvested(wet) biomass affected the efficiency significantly. This study elucidated the need for future research on optimizing this extraction process.

• Journal of Ecology and Environment
• /
• v.37 no.4
• /
• pp.177-184
• /
• 2014

This study was conducted to develop allometric equations and to determine the stem density and biomass expansion factor (BEF) for the estimation of the aboveground and belowground biomass of Cryptomeria japonica in Jeju Island, Korea. A total of 18 trees were harvested from the 40-year-old C. japonica stands in Hannam experimental forest, Jeju Island. The mean biomass of the C. japonica was $50.4Mg\;ha^{-1}$ in stem wood, $23.1Mg\;ha^{-1}$ in root, $9.6Mg\;ha^{-1}$ in branch, $4.6Mg\;ha^{-1}$ in needle and $4.3Mg\;ha^{-1}$ in stem bark. The diameter at breast height (DBH) was selected as independent variable for the development of allometric equations. To evaluate the performance of these equations, coefficient of determination ($R^2$) and root mean square error (RMSE) were used and results of the evaluation showed that $R^2$ ranged from 71% (root biomass equation) to 96% (aboveground biomass equation) and the RMSE ranged from 0.10 (aboveground biomass equation) to 0.33 (root biomass equation). The mean stem density of C. japonica was $0.37g\;cm^{-3}$ and the mean aboveground BEF was $1.28g\;g^{-1}$. Furthermore, the ratio of the root biomass to aboveground biomass was 0.32.

• Journal of Ecology and Environment
• /
• v.33 no.4
• /
• pp.351-361
• /
• 2010

The primary purposes for using fire are to enhance marsh vegetation to support waterfowl, and to manage invasive plant species. The study was conducted for two consecutive years in 2004 and 2005, investigating the effects of prescribed fire regimes on vegetation biomass in tidal brackish marsh areas of the Blackwater National Wildlife Refuge located on the eastern shore of Maryland, USA, that are under relatively similar environmental conditions. Four different burn regimes (i.e., annual burn, 3-5 year burn, 7-10 year burn, and no burn) were applied in the study. Above- and below-ground vegetation biomass samples as affected by the different burn regimes were harvested in each year for five plant species native to the marsh; Distichlis spicata, Spartina alterniflora, Schoenoplectus americanus, Spartina cynosuroides and Spartina patens. No significant difference was found either in total above-ground biomass or in above-ground biomass by species between burn regimes in 2004. However, more total above-ground biomass was produced in annual burn regime in 2005 than in the other burn regimes. There were no consistent effects of burning on vegetative biomass production by species, but it seemed D. spicata was somewhat benefited by prescribed burning for its biomass production. Moreover, the stem density for D. spicata under annual burn regime was significantly higher than that in the other burn regimes, showing some positive effects of burning on vegetation. The below-ground biomass was significantly greater in 2004 than in 2005, yet with no significant difference between burn regimes in either year. A longer-term monitoring is strongly recommended.

• Journal of Korean Society of Forest Science
• /
• v.96 no.5
• /
• pp.602-608
• /
• 2007

Forest plantations become important strategy not merely for the financial aspect, but for carbon sequestration and ecosystem stability. Forest plantations increase the density of the forest biomass, which reduce the increase in atmospheric carbon dioxide. Biomass density is also a useful variable for comparing structural and functional attributes of forest ecosystems across a wide range of environmental conditions. In this study, carbon sequestration of teak (Tectona grandis Linn. f.) in the individual tree and plantation levels estimation was carried out Site-specific allometric equation for the estimation of teak tree biomass was developed based on the direct measurement of fifteen (15) harvested trees in the Oak-twin Township of the Bago Yoma Region, Myanmar. A regression equation of the diameter at breast height (DBH) and the aboveground biomass (carbon content) was constructed to estimate the carbon storage level of plantations, which averaged 79 ton/ha. The average carbon accumulation in the soil (up to 30 cm in depth) was estimated 38.89 ton/ha, The highest mean annual increment (MAI) of total carbon was found in the 6-yr-old teak plantation (12.10 ton/ha/yr) whereas the lowest MAI was in the 26-yr-old teak plantation (4.31 ton/ha/yr).

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.99-99
• /
• 2022

This study was carried out to select the excellent silage maize varieties customized for paddy cultivation that is vulnerable to lodging and waterlogging in the central and region. Ten varieties (Kwangpyeongok, P3394, etc.) were sown with 3 replicates in Suwon, Gyeonggi-do. It was sown twice in April and June of each year in 2020-2021 and harvested during the yellow ripe stage suitable for silage. The number of days to flowering stage in lowland condition increased up to 11 days compared to that in upland condition. In April seedling, varieties that showed a relatively small decrease in biomass production and total digestible nutrients (TDN) under lowland condition compared to upland condition were Gangdaok and Kwangpyeongok in 2020, and Dacheongok, Gangdaok and Kwangpyeongok in 2021. Kwangpyeongok, Gangdaok, and Sinhwangok showed relatively higher biomass production and TDN than the other varieties under lowland compared to upland in both 2020 and 2021. Our results suggest that Kwangpyeongok and Gangdaok are suitable silage maize varieties for lowland cultivation in the central region of Korea.

• Environmental Engineering Research
• /
• v.25 no.3
• /
• pp.393-399
• /
• 2020

The use of different types of wastewater (WW) for the cultivation of microalgae and cyanobacteria during recent decades has provided important economic and environmental benefits. However, direct use of WW can lead to growth inhibition and biomass contamination. In the present study, we separated the key WW nutrients, namely nitrate and phosphate, by adsorption and regeneration and used the resulting regenerated water to cultivate the cyanobacterium Spirulina platensis. The adsorbent was granular γ-alumina derived from waste aluminum cans. This procedure recovered 19.9% of nitrate and 23.7% of phosphate from WW. The cyanobacterial cultures efficiently assimilated the nutrients from the medium prepared using regenerated WW, and the growth and nutrient uptake were similar to those in a synthetic medium. In addition, imposing nutrient limitations to increase carbohydrate productivity was easily achieved using regenerated wastewater nutrients, without requiring additional dilution or complex processing. In acute toxicity tests, the harvested biomass in a regenerated medium had similar toxicity levels compared to the biomass obtained from a synthetic medium. The proposed method of using regenerated WW to produce contamination-free biomass has broad potential applications.

• Korean Journal of Environmental Agriculture
• /
• v.30 no.3
• /
• pp.234-242
• /
• 2011

BACKGROUND: Cultivation of winter cover crops is strongly recommended to increase land utilization efficiency, animal feeding material self-production, and to improve soil and environmental quality. METHODS AND RESULTS: Four major winter crops (barley, Chinese milk vetch, hairy vetch, and rye) having different C/N ratio were seeded in silt loam paddy soil in the November 2007 and the aboveground biomass was harvested on the late May 2008 to evaluate its effectiveness as green manure, and root biomass distribution was characterized at the different depth (0-60 cm) to study its effect on physical properties and carbon sequestration in soil. During this experiment, the naturally growing weed in the rice paddy soil in Korea, short awn foxtail (Alopecurus aequalis Sobol), was considered as control treatment. Above-ground biomass of all cover crops selected was significantly higher than that of the control treatment (2.8 Mg/ha). Comparatively higher above-ground biomass productivity of rye and barley (15.8 and 13.5 Mg/ha, respectively) suggested that these cover crops possibly had the highest potential as a green manure and animal feeding material. Root biomass production of different cover crops followed the same trend as that for their above ground biomass. Rye (Secale cereal) might have the highest potential for soil C accumulation (7893 C kg/ha) by root biomass development, and then followed by barley (6985 C kg/ha), hairy vetch (6467 C kg/ha), Chinese milk vetch (6671 C kg/ha), and control (5791 C kg/ha). CONCLUSION(s): Cover crops like rye and barley having high biomass productivity might be the most effective winter cover crops to increase organic carbon distribution in different soil aggregates which might be beneficial to improve soil structure, aeration etc. and C sequestration.