• 한국토양비료학회지
• /
• 제34권3호
• /
• pp.147-152
• /
• 2001

This study was carried out to investigate the effect of application time and amount of liquid pig manure on growth and yield of rice plant and infiltration water quality. Liquid manure treatment with higher application rate and closer application time to transplanting time showed higher plant height and number of tiller at panicle formation stage, but it caused the plant disease and pest and lodging. In liquid manure treatment with higher application rate, number of panicles per hill and number of spikelets per panicle were higher but yield of rice was less than chemical fertilizer treatment due to low rate of ripeness and 1,000 grain weight. $NO_3-N$ concentration in infiltration water sample was increased with increasing application amount of liquid manure and closer application time to transplanting of rice plant. With consideration yield of rice and environment such as groundwater quality, the proper application amount were 150% and 100% of recommending N fertilizer level (11kg) at before winter and April or May treatment, respectively.

• 한국작물학회지
• /
• 제38권3호
• /
• pp.235-239
• /
• 1993

모시풀 재배에 있어서의 적정 시비량을 알고자 휴지재식 초년부터 성원이된 4년째까지 시험조사한 결과를 요약하면 다음과 같다. 1. 모시풀의 경신장에는 비료 3요소중 질소, 칼리의 증시효과가 컸고, 석회도 경신장에 크게 작용하는 것으로 생각되었다. 2. 기준시비량 $P_2O_5$-$K_2$O=9-3-9kg/10a에 비하여 질소는 2～3배, 칼리는 2배비 시용에서 수량이 증대되었고, 그 중 10a당 질소 18kg, 인산 3kg, 칼리 18kg와 석회 200kg 시용의 경우 가장 유효경 비율도 높았으며 조섬유 수량에서도 33% 증수되었다.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2017년도 9th Asian Crop Science Association conference
• /
• pp.209-209
• /
• 2017

The application of liquid swine manure to soil has been commonly reported to increase crop productivity by improving plant nutrient availability. This study was conducted to investigate the effect of liquid swine manure (LSM) application on yield of green manure crops in paddy. Three different application rates of LSM equivalent to 25%, 50%, and 75% of standard fertilization rate of P were applied to the paddy field after rice harvest, and two cover crops, hairy vetch (Vicia villosa Roth) and barley (Hordeum vulgare L.), were subsequently mix-seeded and cultivated. Plant height of barley was 7% higher in LSM P25% and LSM P50% compared to control treatment (no LSM application), while no significant difference was observed between LSM P75% and control. However, there were no significant differences in plant height of hairy vetch among treatments. Dry matter (DM) yield of green manure increased with LSM application rate, reaching a maximum at LSM P50% (38 and 17% yield increase over control for hairy vetch and barley, respectively), but it decreased at LSM P75% rate. Nitrogen production by green manure crops was the highest in LSM P50% treatment, where the amount of produced N was 57% higher than the optimum N fertilization level for rice ($90kg\;N\;ha^{-1}$). Excess green manure biomass above an optimum level can be removed and utilized either for incorporation into nearby cropland or for sale as fresh forage. Therefore, it is concluded that the application rate of LSM P50% is recommendable for the maximum biomass and nitrogen production from green manure crops in paddy.

• 한국환경농학회지
• /
• 제41권3호
• /
• pp.167-176
• /
• 2022

BACKGROUND: Nitrogen (N) is an important element for turfgrass (Zoysia matrella) growth; however, standard N application rate for turfgrass is not established yet. This study was conducted to evaluate the effect of N application rates on the growth and quality of turfgrass for establishment of standard N application rate. METHODS AND RESULTS: Treatments were as follows; control (0 N g/m²/month), 1N (1 N g/m²/month), 2N(2 N g/m²/month), 3N (3 N g/m²/month), 4N (4 N g/m²/month), and 5N (5 N g/m²/month). N application improved visual turfgrass quality. Compared with the control, clipping yield of all N treatments increased by 90~194%. The grass shoot weight of 3N, 4N, and 5N treatments increased by 52%, 43%, and 111%, respectively, and the stolon weight of 4N and 5N treatments increased by 412% and 201%, respectively, compared to the control. The N uptake amount and N recovery rate were estimated to be 4.10~6.28 g/m² and 14~58%, respectively. CONCLUSION(S): These results indicate that considering visual quality, clipping yield, N uptake amount, and N recovery, the application rate of 2~3 N g/m²/month was suggested to be suitable for Z. matrella production.

• 한국재료학회지
• /
• 제29권12호
• /
• pp.818-824
• /
• 2019

In this study, the direct water quenching technique is applied to validate the applicability of direct water quenching as a cooling method in the hot stamping process of 3.2 mm thick boron steel sheet. Cooling performance of conventional die quenching and direct water quenching is compared. Higher cooling rate is obtained by hot stamping with direct water quenching compared to die quenching. As the flow rate of cooling water increases, the cooling rate increases, and a high cooling rate of 71 ℃/s is achieved under flow rate conditions of 0.8 L/min. Through direct water quenching, the cooling time required for sufficient cooling of the sheet is reduced. Full martensitic microstructure is obtained under flow rate condition of 0.8 L/min. Hardness increases with increasing flow rate. From these results, it is verified that the direct water quenching is applicable to the hot stamping of thick boron steel sheet.

• 한국연초학회지
• /
• 제9권2호
• /
• pp.25-35
• /
• 1987

Effects of application time And rate of chlorine on the chlorine absorption and distribution at different stalk positions of the plants were Investigated in burley tobacco grown under the pot condition. Treatment consisted of 6 application times (from 2 weeks before transplanting to 8 weeks after transplanting with 2 weeks' interval) and 2 application rates (2g and 4g-KCl/pot) by 6X2 factorial experimental design. The tobacco plants took up the chlorine rapidly just after chlorine application, and the chlorine content of leaf was increased proportionally to the rate of chlorine application. The chlorine was accumulated when much in lower leaves when chlorine was applied early, while the chlorine accumulated much in upper leaves when chlorine was applied late. The chlorine content of leaf was negatively correlated to the degree of brightness, red color and yellow color of cured leaf. Significant Increases In cured leaf ratio, leaf thickness, leaf weight and weight Per unit leaf area of harvested leaf were obtained with increased chlorine application. When the chlorine was applied early, the leaf weight showed Increasing tendency.

• 한국레이저가공학회지
• /
• 제16권2호
• /
• pp.1-6
• /
• 2013

Picosecond lasers are a very effective tool for micromachining metals, especially when high accuracy, high surface roughness and no heat affected zone are required. However, low productivity has been a limit to broadening the spectrum of their industrial applications. Recently it was reported that in the micromachining of copper with a 1064nm picosecond laser, there exist the optimal pulse energy and repetition rate to achieve the maximum volume ablation rate. In this paper, we used a 515nm picosecond laser, which is more efficient for micromachining copper in terms of laser energy absorption, to obtain its optimal pulse energy and repetition rate. Theoretical analysis based on the experimental data on copper ablation showed that using a 515nm picosecond laser instead of a 1064nm picosecond laser is more favorable in that the calculated threshold fluence is 75% lower and optical penetration depth is 50% deeper.

• 한국해양공학회지
• /
• 제11권3호
• /
• pp.76-88
• /
• 1997

Constant .DELTA.K fatigue crack growth rate experiments were performed by applying an intermediate single and multiple overload for structural steel, SM45C. The purpose of the present study is to investigate the influence of multiple overloads at various stress intensity factor ranges and the effect of statistical variability of crack retardation behavior. The normalized delayed load cycle, delayed crack length and the minimum crack growth rate are increased with increasing baseline stress intensity factor range when the overload ratio and the number of overload application were constant. The crack retardation under low baseline stress intensity factor range increases by increasing the number of overload application, but the minimum crack growth rate decreases by increasing the number of overload application. A strong linear correlation exists between the minimum crack growth rate and the number of overload applications. And, it was observed that the variability in the crack growth retardation behavior are presented, the probability distribution functions of delayed load cycle, delayed crack length and crack growth life are 2-parameter Weibull. The coefficient of variation of delayed load cycle and delayed crack length for the number of 10 overload applications data are 14.8 and 9.2%, respectively.

• 한국작물학회지
• /
• 제53권spc호
• /
• pp.31-36
• /
• 2008

규산 시용에 따른 수량 및 미질 관련해서는 많이 보고되고 있지만 도정 특성과 관련된 보고와 특히 저장관련 자료가 거의 없어 이에 대한 연구를 수행하여 다음과 같은 결과를 얻었다. 1. 수량 및 수량구성요소에서는 규산 시용구에서 수수 및 영화수가 증가하였으며, 등숙비율도 2%이상 증가하여 완전미 수량은 $7.7{\sim}9.5%$정도 증가하였다. 2. 미질 특성의 이화학적 성분 함량은 규산시용에 따라 단백질 함량은 $0.2{\sim}0.3%$ 감소하였으며, 쌀의 외관상 품위 변화는 시용량이 증가할수록 분상질립 및 피해립율이 감소되면서 완전미의 비율이 규산 무시용(83.2%)에 비해 규산 1배 시용시 85.6%, 1.5배 시용시 86.4%, 2배 시용시 88.7%로 높아지는 효과가 있었다. 3. 규산을 시용함에 따른 색체 선별율은 $4.2{\sim}7.2%$ 향상되었고, 색미율은 $5.5{\sim}16.6%$ 낮아져 완전미 도정수율은 $5.5{\sim}8.6%$향상되었다. 4. 규산 시용에 따른 저장성 변화에 있어서 지방산도는 저온 저장($15^{\circ}C$)에서는 저장기간에 따른 큰 변화는 없었으나, 상온저장에서는 6월 이후 증가하여 노화가 급격하게 진행되었다. 5. 쌀의 pH에 의한 최상위 등급 비율은 저온 저장에서는 9월 이후부터 낮아지는 경향이나, 상온 저장에서는 6월부터 급격히 낮아져 신선도가 현저히 저하되었으며, 저온과 상온 저장 모두 규산 시용구에서 쌀의 신선도가 무시용구에 비하여 오래 지속되는 경향이었다.

• 한국토양비료학회지
• /
• 제7권2호
• /
• pp.113-118
• /
• 1974

수도(水稻)에 대한 질소질비료(窒素質肥料)의 분시효과(分施効果)와 시용시기(施用時期)에 따른 비료(肥料)의 흡수율(吸收率)과 흡수(吸收)된 비료(肥料)의 수도체내(水稻體內)에서의 분포(分布)를 조사(調査)키 위하여 정보당(町步當) 10kg의 질소질비료(窒素質肥料)를 전양기비(全量基肥)와 생육시기(生育時期)에 따라 4회(回)에 나누어서 분시(分施)한 시험결과(試驗結果)는 다음과 같다. 사용한 질소질비료(窒素質肥料)는 중질소(重窒素)로 표식(標識)된 유산암모니아를 사용(使用)한 시험결과(試驗結果)이다. 1. 질소질비료(窒素質肥料)의 분시효과(分施效果)가 컸다. 질소전량기비구(窒素全量基肥區)의 해미(亥米) 수량(收量) 3.1 ton/ha에 대하여 분시구(分施區) 3.4 ton/ha이었고 질소결제구(窒素缺制區)는 1.9ton/ha었다. 2. 수당입수(穗當粒數)와 천입중(千粒重)은 분시구(分施區)가 높았고 주당수수(株當穗數)와 등숙비(登熟比)는 전량기비구(全量基肥區)가 높았다. 3. 기비(基肥), 1차추비(追肥), 2차추비(追肥)와 3차추비(追肥)로 시용(施用)한 질소질비료(窒素質肥料)의 흡수율(吸收率)은 각각 28%, 33%, 51%와 63%였다. 4. 경엽중(莖葉中)에 함유(含有)되었던 질소(窒素)가 출수(出穗)이후 이삭 부분으로 이동(移動)되며 지엽발생기(止葉發生期)에 시비(施肥)한 질소(窒素)가 제일 많이 이삭쪽에 분포(分布)되었다.