• Journal of Bio-Environment Control
• /
• v.21 no.1
• /
• pp.57-65
• /
• 2012

Fertilization is essential to seedling production in nursery culture, but excessive fertilization can contaminate surface and ground water around the nursery. The objective of this study was to find optimal fertilization practice of container seedling production for reducing soil and water contamination around the nursery without compromising seedling quality. This study was conducted to investigate chemical properties of the growth medium, growth performance, chlorophyll fluorescence, and chlorophyll contents of larch ($Larix$ $kaempferi$) growing under three different fertilization treatments (Constant rate, Three stage rate, and Exponential rate fertilization). Root collar diameter and height of larch were not significantly different among treatments even though the nutrient supply of the exponential treatment was half that of the constant and three stage treatments. Chemical properties of the growth medium showed the same trends as root collar diameter and height. The total biomass and seedling quality index (SQI) were higher at Constant than at other treatments, but both SQI of Constant and Exponential were not significantly different. Photochemical efficiency and chlorophyll contents were lower at Exponential than at other treatments, but not significantly different among treatments. Therefore, Exponential fertilization which is 50% fertilizer of other treatments would maximize seedling growth and minimize nutrient loss.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.05a
• /
• pp.172-172
• /
• 2011

Anaerobic digestion(AD) has successfully been used for many applications that have conclusively demonstrated its ability to recycle biogenic wastes. AD has been successfully applied in industrial waste water treatment, stabilsation of sewage sludge, landfill management and recycling of biowaste and agricultural wastes as manure, energy crops. During AD, i.e. organic materials are decomposed by anaerobic forming bacteria and fina1ly converted to excellent fertilizer and biogas which is primarily composed of methane(CH4) and carbon dioxide(CO2) with smaller amounts of hydrogen sulfide(H2S) and ammonia(NH3), trace gases such as hydrogen(H2), nitrogen(N2), carbon monoxide(CO), oxygen(O2) and contain dust particles and siloxanes. The production and utilisation of biogas has several environmental advantages such as i)a renewable energy source, ii)reduction the release of methane to the atomsphere, iii)use as a substitute for fossil fuels. In utilisation of biogas, most of biogas produced from small scale plant e.g. farm-scale AD plant are used to provide as energy source for cooking and lighting, in most of the industrialised countries for energy recovery, environmental and safety reasons are used in combined heat and power(CHP) engines or as a supplement to natural. In particular, biogas to use as vehicle fuel or for grid injection there different biogas treatment steps are necessary, it is important to have a high energy content in biogas with biogas purification and upgrading. The energy content of biogas is in direct proportion to the methane content and by removing trace gases and carbon dioxide in the purification and upgrading process the energy content of biogas in increased. The process of purification and upgrading biogas generates new possibilities for its use since it can then replace natural gas, which is used extensively in many countries, However, those technologies add to the costs of biogas production. It is important to have an optimized purification and upgrading process in terms of low energy consumption and high efficiency giving high methane content in the upgraded gas. A number of technologies for purification and upgrading of biogas have been developed to use as a vehicle fuel or grid injection during the passed twenty years, and several technologies exist today and they are continually being improved. The biomethane which is produced from the purification and the upgrading process of biogas has gained increased attention due to rising oil and natural gas prices and increasing targets for renewable fuel quotes in many countries. New plants are continually being built and the number of biomethane plants was around 100 in 2009.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.37 no.3
• /
• pp.224-229
• /
• 1992

The objective of the study was to clarify the pattern of fertilizer absorption by tillering hybrid, IK$_1$/IRI. Nangano No.1 hybrid was included as non-tillering check hybrid. Hybrids were grown in pots and the plants were periodically analyzed for their chemical components like nitrogen, phosphorus, potassium, calcium and magnesium. The results obtained indicate that the amount of nitrogen, phosphorus and potassium absorbed by IK$_1$/IRI was slightly lower than that absorbed by Nangano No.1, except nitrogen in the maturity of IK$_1$ /IRI. However, no major differences were observed for the calcium and magnesium content between two hybrids. In most cases amount of nitrogen and calcium in the plant of two hybrids seemed to decrease as the plants mature, while amount of those chemicals in the ears increased. Nitrogen efficiency for IK$_1$ /IRI seemed a little lower than that for Nangano No.1.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.33 no.3
• /
• pp.222-228
• /
• 1988

This experiment was carried out to investigate the effects of N levels (0,10,20,30kg/10a) and N split rates [the rates of basal＋top dressing 15 days after transplanting (DAT) : top dressing 25 days before heading (DBH) was 100 : 0, 80 : 20, 60 : 40 ] on the growth, yield, yield components, and N uptake of Seomjinbyeo (J) and Samgangbyeo (I${\times}$J). The maximum tillering stage occurred in the middle of July in both varieties, but Samgangbyeo showed the second maximum tillering stage in the middle of August probably due to the retarded early growth caused by low temperature in the tillering stage and to favoring temperature in August. Grain yield of Seomjinbyeo was similar among the N levels from 10 to 30 kg/10a without occurrence of rice blast and lodging, but that of Samgangbyeo increased as N level increased upto 30 kg/10a. Grain yield of Seomjinbyeo was higher when N was applied three times (basal and two top dressings 15 DAT and 25 DBH) compared with two times (basal and top dressing 15 DAT), but that of Samgangbyeo was not different among the N split rates. Total N uptake and the proportion of fertilizer N to the total N uptake increased as N level was higher. N uptake tended to be higher as proportion of basal＋top dressing 15 DAT increased in early growth stage, but it was higher as proportion of N applied 25 DBH increased in the late growth stage. The N efficiency to produce grain per absorbed N unit decreased as N level decreased in Seomjinbyeo, but similar in Samgangbyeo.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.21 no.3
• /
• pp.99-107
• /
• 2013

In this study, field scale test was conducted to estimate the TMDL coefficients (runoff and leachate:(${\beta}4$)(${\beta}5$)(${\beta}8$)) for the livestock resources applying to agricultural crop land as fertilizer, and the results were obtained as follows. Each waste reduction coefficient(${\beta}4$) was shown to be in the range of 0.94~0.75 for public waste treatment plants and 0.99~0.83 for private waste treatment in the analysis of BOD, COD, SS, T-N, T-P, TOC. Thus private plants showed higher rate. Waste treatment discharge into the land coefficient (${\beta}5$) was also shown to be in the range of 0.4.~0.24 for public plants and 0.75~0.16 for private plants, so it is much lower than other coefficients. However SS and T-P were shown to be much higher for land discharge in private plants than in public plants. Treatment coefficient in the public plants (${\beta}8$) appeared to be average 0.75 for T-P but over 90% treatment efficiency and also large deviation were observed due to 0.2 of some other treatment plants.

• Ocean and Polar Research
• /
• v.35 no.4
• /
• pp.407-414
• /
• 2013

One of the most important challenges facing the Spirulina mass cultivation industry is to find a way to reduce the high production costs involved in production. Although the most commercial medium (Zarrouk's medium) for Spirulina cultivation is too expensive to use, it contains higher amount of $NaHCO_3$ (16.80 g $L^{-1}$), trace metals and vitamin solutions. The purpose of this study was to increase the efficiency of Spirulina platensis biomass production by developing a low-cost culture medium at an isolated tropical island such as Chuuk State, Federated States of Micronesia (FSM). This study set out to formulate a lowcost medium for the culture of S. platensis, by substituting nutrients of Zarrouk's medium using fertilizer- grade urea and soil extract with a different concentration of carbon source under natural weather condition. In order to select a low-cost culture medium of S. platensis, 10 culture media were prepared with different concentrations of nitrogen (urea and $NaNO_3$) and $NaHCO_3$. The highest maximum specific growth rate (${\mu}max$) and mass production were 0.50 $day^{-1}$ and 1.05 g $L^{-1}$ in modified medium ($NaHCO_3$ 7.50 g $L^{-1}$, urea 2.00 g $L^{-1}$ without $NaNO_3$) among all the synthesized media. Protein (56.14%) and carbohydrate (16.21%) concentrations of the lyophilized standard samples were estimated with highest concentration of glutamic acid (14.93%). This study revealed that the use of a low concentration of urea and $NaHCO_3$ with soil extract was an affordable medium for natural mass cultivation in the FSM.

• Journal of Bio-Environment Control
• /
• v.16 no.4
• /
• pp.352-357
• /
• 2007

We investigated effects of concentration and duration were investigated in order to promote efficiency of $CO_2$ enrichment in winter. The treatments were conducted with two levels of $CO_2$ concentration, namely 400 ppm, 700 ppm, two levels of duration, 3 h (9:00-12:00), 6 h (9:00-15:00), and control (nonenrichment $CO_2$). Fresh weight of leaves increased under longer exposure to $CO_2$ and higher $CO_2$ concentration. Fresh weight of stem and root increased under longer exposure to $CO_2$, but decreased under higher $CO_2$ concentration. Total dry weight increased under longer exposure to $CO_2$ and higher $CO_2$ concentration. Combination treatment of longer exposure to $CO_2$ and higher $CO_2$ concentration showed the largest decrease of Root : Shoot dry weight ratio. The $700ppm{\times}6h$ treatment showed higher fruit number and yield than control. The results suggested that the growth under longer exposure to 400 ppm $CO_2$ was better than that under higher $CO_2$ concentration.

• Korean Journal of Environmental Agriculture
• /
• v.28 no.1
• /
• pp.15-19
• /
• 2009

Ammonia in atmosphere has a negative effect on the natural ecosystems, such as soil acidification and eutrophication, by wet and dry deposition. Livestock manure, compost, and fertilizer applications to arable land have been recognised as a major source of atmospheric ammonia emissions. The objective of this study was to evaluate the efficiency of compost application techniques in reducing ammonia loss in upland soil. The reductions in ammonia emission were 70 and 15% for immediate rotary after application (IRA) and rotary at 3 day after application (RA-3d) in comparison with surface application (SA). Total ammonia emissions for 13 days, expressed as % ammonia-N applied with compost, were 42, 35.7, and 12.7% for SA, RA-3d, and IRA treatments, respectively. The ammonia emission rate fell rapidly 6 h after application and 61 % of total ammonia emission occurred within the first 24 h following surface application. The lime application along with compost significantly enhanced the total ammonia emission. Total ammonia emission for 22 days were 40.1, 31.4, and 27.7 kg/ha for immediate incorporation in soil after lime and compost application, lime incorporation in soil following 3 days after compost surface application, and compost incorporation in soil following 3 days after lime surface application, respectively. Therefore, lime and livestock manure compost application at the same time was not recommended for abatement of ammonia emission in upland soil.

• Korean Journal of Organic Agriculture
• /
• v.13 no.1
• /
• pp.85-99
• /
• 2005

This trial was carried out to determine effects of organic feeds in comparison to conventional diet on feed intake, digestibility, and nitrogen retention in Korean native goats. Twelve Korean native goats were allotted to treatments in four groups of three goats and then they were housed in separate metabolism cages for 21 days. Treatments included conventional diet (A) as a control group and three organic feed groups (B: organic rice straw, C: organic nee leaves, D: organic mixture of rice straw and tree leaves). The A treatment, conventional diet, consisted of common rice straw and commercial concentrates at a proportion of 60 and 40%, respectively. All ingredients of organic feeds treatments were organically produced-agricultural products without any application of chemical fertilizer and pesticide. Four experimental diets were formulated to have the same ratio of forage to concentrate and similar contents for protein and carbohydrate across treatments and they were offered to goats ad libitum. Feed intake, apparent nutrient digestibility and nitrogen retention were investigated. For chemical compositions of experimental diets, all nutrients except crude ash and ether extract were not significantly different across treatments as we expected. Crude ash content was highest in the A treatment (P<0.05), however, it was not significantly different among organic feeds treatments. Ether extract content was higher (P<0.05) in C and D treatments than in A and B. Even if dry matter intakes for organic feeds treatments were not significantly different among them, they were significantly higher (P<0.05) compared with conventional diet. Fecal excreta were not significantly different across treatments, resulting in significantly higher digestible dry matter (g/day) in treatments of organic feeds (P<0.01). Average daily gain (ADG) and feed efficiency (FE) were more increased (P<0.01) in treatments of organic feeds compared with conventional diet. Digestibilities for most of nutrients except NFC had the same trend as ADG and FE, however, NFC digestibilities for C and D treatments were significantly lower (P<0.01) than those of A and B. Nitrogen intakes for organic feeds treatments were significantly higher (P<0.001) than conventional diet, with no difference among organic feeds treatments. Fecal nitrogen loss was higher (P<0.05) for C and D treatments than for A and B. Retained nitrogen contents were significantly higher (P<0.05) for organic feeds treatments than for conventional diet, but nitrogen retention rate did not show any difference across treatments. The results showed that organic feed supplementation more improved feed intake, digestibility and nitrogen retention in comparison with conventional diet, and thus they could be concluded that organic feeds might contribute to animal performance and a safer production of animal product.

• Korean Journal of Environmental Agriculture
• /
• v.17 no.1
• /
• pp.54-58
• /
• 1998

This experiment was conducted to find out the effects of fermented compost using cattle manure and Autoclaved Lightweight Concrete(ALC) waste and duck raising in rice growing paddy fields on growth and quality of rice. By application of fermented compost of cattle manure incoporated ALC waste with amount of 2,000kg/10a, rice yield was reduced 2.9%, and 4.1% in 1,000kg/10a of compost with raising ducks plots as compared with application of standard level of chemical fertilizer. The ratio of head rice was slightly high in plots of compost application and white-belly kemeled rice was reduced by application of $1,500{\sim}2000kg/10a$ compost. The ratio of Mg/K was the highest in application of 1,000kg compost with raising duck. Efficiency of weed control by raising duck with free hexbiades was sufficient and their effects showed no difference between raising duck plots and herbidde plot.