• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.31 no.4
• /
• pp.454-464
• /
• 1986

To find main factors to affect tobacco culture and quality, NC 2326 (Nicotiana tabacum L.) was cultivated in Korea and in the United States under different plant density, fertilization, mulching and curing. Among the chemical characteristics of the both experimental soils, the organic matters were similar concentration in both locations but effective phosphorous contents were higher in Oxford in the United States. Plant height, length and width of the largest leaf, leaf thickness, and midrib ratios were larger in Oxford than in Suwon in Korea. Also they were larger in non mulching system than in mulching system. But the total numbers of the leaves were decreased in non mulching system. The content of nicotine was higher in the plant grown in Suwon than in Oxford. The concentrations of nicotine and sugar tend to increase in mulching system comparing of non mulching system. During the growing, the concentration of non-volatile organic acids was higher in Suwon, while it was lower in cured leaf produced in Suwon. Also the contents of total fatty acids were lower in the harvested leaf grown in Suwon, but not in cured tobacco. Forty three compounds identified among the volatile oils from these experimental samples were quantified. The concentrations of the major components related to the tobacco flavour such as damascone, damascenone, solanone, nor-solanadione, and megastigmatrienones were higher in the cured tobacco produced in Oxford rather than in Suwon.

• Journal of Korean Society for Atmospheric Environment
• /
• v.33 no.3
• /
• pp.191-204
• /
• 2017

Concerns on the air pollution problem caused by ambient fine particles have become a big social issue in Korea. Important factors that should be addressed to develop effective and efficient air quality management policy, especially, against fine particles are discussed and research and policy directions to address these factors are suggested. It is suggested that two factors are in high priority; one is scientific understanding of the major formation mechanisms of fine particles and the other is the process of policy decision and implementation. For the scientific understanding, smog chamber measurement, intensive field study, and chemical transport model development that can simulate the characteristics of Northeast Asia are considered to be important. For the policy directions, priority setting of the proposed policies and development and implement of effective communication sytem are considered to be important.

• Korean Journal of Environmental Agriculture
• /
• v.24 no.2
• /
• pp.180-184
• /
• 2005

This study was peformed to assess environmental effect through rice culture with sewage irrigation using Iksan stream water from 2002 to 2003. Contents of $NH_4-N$ in irrigation water keep up one day at the tillering stage and panicle formation stage were decreased 40% and 52% respectively, but that of continued 4 days was decreased $88%{\sim}98%$. The $NH_4-N\;and\;NO_3-N$ in run off by reduction 50% fertilization were more decreased 17% and 44% respectively, than those of conventional fertilization level. Amount of K and $NO_3-N$ loss in infiltration water were more decreased 18% and 4% respectively, those of than conventional fertilization level. The Cu and Pb contents in soil of after experiment were slightly increased but other heavy metals were not accumulated. The rice yield by reduction 50% fertilization level was not significant compare with conventional fertilization level but head rice rate was increased.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.23 no.1
• /
• pp.31-36
• /
• 2003

This pot experiment was conducted te find out the effects of kieserite application ($T_1$; control, $T_2$; standard amount of $N-P_2$$O_{5}$ $-K_2$0, $T_3$; $T_2$+ kieserite) on the seedling vigour and yield of pass/clover mixed swards on newly reclaimed hilly soil. The results obtained are summarized as follows: At the $T_1$ treatment the seedling vigour and yield of mixed forages were very poor, whereas they were remarkedly enhanced by the treatments of $T_2$ and $T_3$. Comparing with the $T_2$ treatment the forage yields were increased 3.1% in orchardgrass, 27.5% in ladino clover, and 12.8% in mixed forages by the application of kieserite($T_3$). In the grass-clover mixed swards, the application of kieserite more remarkedly influenced the seedling vigour, botanical composition, and yield of clover than those of grass.

• Applied Biological Chemistry
• /
• v.15 no.3
• /
• pp.229-240
• /
• 1972

Not only in order to determine reasonable application amounts of PCP in terms of soil texture, but also to get basic data for fish-toxicity-free treatment by estimating fish toxicity, some aspects of PCP adsorption were observed taking various paddy soils with different physico-chemical characteristics in the Choongbook Area as samples. The results obtained are summarized as follows: 1. There was a positive correlation between PCP adsorption and clay contents, total nitrogen, organic matter, cation exchange capacity, exchangeable bases, and phosphorus absorption coefficients, respectively; whereas there was a negative one between PCP adsorption and pH. Although they were not significant, it was remarkable that there was a relatively large amount of correlation between PCP adsorption and clay contents, $H^+,\;Mg^{++}$, and CEC, respectively. 2. PCP adsorption in terms of soil texture was in the order of Clay>Loam>Sandy loam. 3. Although PCP adsorption in the $H_2O_2-treated$ soils decreased remarkably, it was not proportional to the humus contents. 4. The order of PCP adsorption in the exchangeable base-treated soils was H^+-exchanged soil>$K^+-soil$>$Na^+-soil$>$Ca^{++}-soil$>Mg^{++}-soil. 5. Langmuir's and Freundlich's adsorption isotherms were applicable to the PCP adsorption, and thereby were able to be calculated maximum adsortion amounts of PCP, bond energy, and the depths of adsorption layers. 6. Maximum adsorbed amounts of PCP were 212.14 mg/100gr in Clayey loam, 97.28 to 121.59mg/100gr in Loam, and 32.92 to 91.74mg/100gr in Sandy loam, respectively. 7. The depths of mixed layers of limiting application for fish-toxicity-free treatment were 0.88cm of the Jinchun soil, the shallowest and 4.29 cm of the Naesan-ri Sandy loam, the deepest.

• Proceedings of the Korean Society of Organic Agriculture Conference
• /
• 2009.12a
• /
• pp.299-299
• /
• 2009

유기농업에서 유기자원을 이용하여 적정량의 양분을 공급하기 위해서는 먼저 유기자원의 무기화특성을 고려하여야 한다. 토성, 기온, 재배형태 등 다양한 요인을 고려하면서 무기화모델을 이용하여 유기농업에서 많이 사용되고 있는 유기질비료와 작물잔사 등을 대상으로 잠재 무기화가능 질소량(PMN, Potentially mineralizabe nitrogen)을 추정하였다. 실험은 실내에서 항온 배양하여 유기자원별 질소 무기화 양상을 분석함으로서 대상 유기자원의 PMN 및 무기화 속도를 도출하였다. 실험재료는 팜박, 피마자박, 팽화왕겨, 토마토, 수박, 감자, 마늘 등 7종을 대상으로 $20^{\circ}C,\;25^{\circ}C,\;30^{\circ}C$ 조건에서 하였으며, 최대수분보유량의 60% 수준으로 하여 사양토 및 식양토 조건에서 실험하였다. 유기자원은 토양 100g에 질소 30kg/10a 해당량을 시용하여 112일까지 항온하였다. 토성별 무기화량은 식양토 보다 사양토에서 다소 높은 경향을 보였다. 또한 항온온도가 높을수록 무기화량이 증가하였다. 유기자원별로는 피마자박에서 높았고, 팽화왕겨는 낮은 경향이었다. 유기자원이 처리된 것에서 토양 자체의 무기화량을 뺀 순무기화량은 피마자박, 토마토잔사, 감자잔사가 항온초기부터 무기화가 진행되었으며, 수박잔사, 마늘잔사는 항온 초기에 음의 값을 가지는 유기화 과정을 거친 후 항온 60일에서 80일 사이에서 무기화가 진행되었고 팽화왕겨의 경우 항온 11일까지 유기화가 계속되었다. PMN 및 무기화속도를 추정하기 위하여 반응속도식을 이용하였으며, 모델의 적합도를 높이기 위하여 이중지수모형을 이용하여 매개변수를 결정하고 무기화경향을 예측한 결과 PMN은 피마자박>마늘잔사=팜박>수박잔사=토마토잔사>감자잔사의 순이었다. 또한 유기자원의 무기화량과 C/N율과는 부의 상관관계($r^2$=0.8653)를 나타내었다. 요소의 PMN(135.6mg/kg)에 대한 유기자원별 PMN의 상대적 비율은 피마자박이 100%, 팜박과 마늘잔사가 81%, 토마토, 수박 및 감자잔사가 28~65% 수준이었다.

• Proceedings of the Korean Society of Organic Agriculture Conference
• /
• 2009.12a
• /
• pp.296-296
• /
• 2009

국제기준(Codex)에 부합하는 유기농산물의 생산을 위해서는 저항성 품종의 유기종자 사용을 원칙으로 규정하고 있으나, 현재까지 우리나라의 경우는 찰옥수수 등 주요 식량작물에 대한 유기채종기술이 거의 전무한 실정이다. 본 연구는 찰옥수수 유기채종기술 확립을 위한 기초 자료로 이용하고자 찰옥수수 유기 채종에 따른 파종기별 생육 및 수량특성에 대하여 검토하였다. 유기종자 생산을 위한 채종시험은 홍천군 남면에 위치한 농가 유기포장에서 수행되었으며, 시험품종은 옥수수시험장에서 육성 보급되고 있는 미백2호 및 미흑찰 원종종자를 이용하였다. 파종기는 4월 16일, 5월 4일, 5월 27일 등 3처리로 구분하여 모 부본 동시파종 하였다. 재식밀도는 80${\times}$25cm로 하여 점파하였고 모 부본의 재식비율은 2:1로 웅주간파 하였다. 잡초방제는 흑색 P.E. Film으로 멀칭 재배하였고, 유기질비료는 H사에서 생산된 혼합유박비료를 전량 기비로 시용하였다. 파종기별 출사일수는 미백2호의 경우 4월 파종에서 79일로 가장 길었고, 파종 시기가 늦을수록 출사일수는 짧아지는 경향을 보였다. 미흑찰의 경우에는 미백2호의 결과와 같은 경향으로 파종시기가 늦을수록 출사일수가 빨라지는 경향을 보였으며, 간장 및 착수고 또한 미백2호와 미흑찰 모두 4월 파종에서 가장 높았고, 파종기가 늦을수록 낮아지는 경향이었다. 이삭특성에 있어서 이삭장과 착립장은 미백2호 및 미흑찰 모두 4월 중순 및 5월 상순 파종간에 큰 차이가 없었으나, 5월 하순 파종에서 현저하게 짧아지는 경향을 보였다. 발아율의 경우 미백2호는 4월 중순 및 5월 상순 파종에서, 미흑찰은 5월 상순 파종에서 높게 나타났다. 종실중과 100립중은 미백2호 및 미흑찰 모두 4월 중순과 5월 상순 파종간에 큰 차이가 없었고, 5월 하순 파종에서 현저하게 감소하였다. 10a당 채종수량은 미백2호의 경우 4월 상순 파종에서 217㎏으로 가장 높았고, 미흑찰은 5월 상순 파종에서 164kg/10a으로 가장 많았으며, 두 품종 모두 5월 하순 파종에서 채종수량의 뚜렷한 감소가 나타났다. 따라서 찰옥수수 유기종자의 안정적 채종과 정상수량 확보를 위해서 미백2호는 4월 중순 파종시에 그리고 미흑찰은 5월 상순 파종시에 채종 안전성이 가장 우수한 것으로 판단되었고, 또한 채종수량에 직접적으로 영향을 미치는 1개 이삭당 종실중과 100립중도 크게 증가하는 것으로 나타났다.

• Applied Biological Chemistry
• /
• v.44 no.4
• /
• pp.240-245
• /
• 2001

Suppression of nitrate accumulation in vegetables through foliar application of micronutrients was investigated. Spinach and lettuce were grown in pots under greenhouse condition. Micronutrient solutions containing Cu, Mn, Mo, and Zn were used; chitosan was added into one and the other contained chitosan oligomers. The micronutrient solutions were sprayed on the leaves at 3 and 4 weeks after transplanting of 20-day-old seedlings. Plants were harvested at 5-weeks after transplanting. Yield, contents of chlorophyll, Brix value, micronutrient, and nitrate, and nitrate reductase activity were measured. Fresh weights of lettuce and spinach were significantly increased by the foliar application of micronutrients. Contents of chlorophyll and micronutrients were higher in micronutrient-treated plants, while those of nitrate were reduced by about 10 and 14-23% in lettuce and spinach, respectively. Compared to the control plants, nitrate reductase activity was higher in plants treated with micronutrients. Results of this study indicate the effect of micronutrients on the suppression of nitrate accumulation was relatively small in comparison to the contents of nitrate in leaves of spinach and lettuce. To maximize the effect, nutrient composition in solution, application time, and frequency should be further examined, taking into consideration nitrogen level in soil and other environmental factors including light condition.

• Korean Journal of Soil Science and Fertilizer
• /
• v.34 no.5
• /
• pp.358-364
• /
• 2001

To obtain information for the proper fertilization management of cut-flower roses, the amount of macro and micro elements absorbed by cut-flower roses from soil for a year was investigated. Three cut-flower rose cultivars which are called 'Grandgara', 'Nobless', and 'Centina' were transplanted to a sandy loam soil, N-P-K standard fertilization was applied to the soil, and drip irrigation was done at the level of 10 kPa soil moisture tension. There was not significantly different in the harvest amount of cut-flower rose between 'Grandgara' and 'Nobless', but the harvest yield of 'Centina' was about 63% level when compared to that of 'Grandgara'. Considering seasonal changes in the content of nutrients in plant, parts, the uptake of untrients was higher in winter season than that in spring and summer seasons. Except for 'Centina', the nutrient amount removed from plant parts of 'Grandgara' and 'Nobless' increased with the sequence of floral part < stem < leaf, indicating that it is more dependent on biomass yield than on the content of nutrients in each plant part. The ratio of N/K amount absorbed by 'Nobless' and 'Centina' was 1.13 and 1.28. respectively, lower than 1.68 of 'Grandgara', showing that the requirement for K is greater in 'Nobless' and 'Centina' than in 'Grandgara'. The use efficiency of nutrients by cut-flower roses ranged from 39 to 64% in nitrogen, 5 to 9% in phosphorus, and 37 to 67% in potassium. It suggests that the requirement for P in cut-flower roses is very low.

• Korean Journal of Organic Agriculture
• /
• v.25 no.2
• /
• pp.475-487
• /
• 2017

The aim of this study was to solve the problem of yield loss causing the lag of fertilizer efficiency after tiller stage, being originated by applying mixed expeller cake fertilizer on three day before rice transplanting in organic rice farmers. The mineralization degree of $NH_4-N$ of the mixed expeller cake fertilizer was increased until 7 weeks at flooding condition, and so did $NO_3-N$ until 5 weeks at non-flooding condition. The mineralization rate of nitrogen in paddy soil on 20 days before rice transplanting was the highest by 0.85% on 20 days before the transplanting treatment. The properties of yields during the harvest period have no difference with application time of the mixed expeller cake fertilizer, except soil organic matter. The plan length, culm length and panicle length were the longest on 20 days before rice transplanting. Also, the number of tiller, ripening rat and 1,000 grain weight were the highest on 20 days before rice transplanting, and thereby the yield of white rice were increasing by 9% on 20 days before rice transplanting compared with that of 3 days before rice transplanting. The whiteness values of the rice and amylose content made no difference, but the value of protein and palatability were the same between 20 days and 30 days treatment. In the conclusion, the relationship between rice yield, its quality and application time of the mixed expeller cake fertilizer has showed that the suitable time of applying it reveals 21.3 days before rice transplanting.