The spectrum of this study was research on the closed hydroponic cultivation of netted melons (Cucumis melo L.) using coir substrate, analyzing the impact of this cultivation method on melon yield, fruit quality, and the efficiency of water and nutrient usage. The experimental results showed that the average fruit weight of the melons grown in a closed system was 71.4 g higher than that of the open system, and the fruit width was on average 0.2 cm larger, showing a statistically significant difference. However, there was no difference in the average sugar content of the fruit flesh and height. Although there is no substantial commercial difference, it is conjectured that the change in the macronutrients ratio in the irrigation has played a role in the statistically significant increase in fruit weight, which is attributed to changes in the crops' nutrient uptake concentrations. This necessitates further research for a more comprehensive understanding. In terms of the productivity of irrigation required to produce the fruit, applying the closed system resulted in an increase of 7.6 kg/ton compared to the open system, saving 31.6% of water resources. Additionally, in terms of nutrients, cultivating in a closed system allowed for savings of approximately 59, 25, 55, 83, 76, and 87% of N, P, K, Ca, Mg, and S, respectively, throughout the entire cultivation period. As the drainage was reused, the ratios of NO3 - and Ca2+ increased up to a maximum of 9.6 and 9.1%, respectively, while the ratios of other ions gradually decreased. In summary, these results suggest that closed hydroponic cultivation can effectively optimize the use of water and fertilizer while maintaining excellent fruit quality in melon cultivation.

The objective of this study was to verify the effect of pig slurry application with acidification and biochar on feed value, nitrogen use efficiency (NUE) of maize forage, and ammonia (NH3) emission. The four treatments were applied: 1) non-pig slurry (only water as a control, C), 2) only pig slurry application (P), 3) acidified pig slurry application (AP), 4) acidified pig slurry application with biochar (APB). The pig slurry and biochar were applied at a rate of 150 kg N ha-1 and 300 kg ha-1, respectively. The AP and APB treatments enhanced all feed values compared to C and P treatments. The NUE for plant N was significantly increased 92.1% by AP and APB treatment, respectively, compared to the P treatment. On the other hand, feed values were not significantly different between AP and APB treatments. The acidification treatment with/without biochar significantly mitigated NH3 emission compared to the P treatment. The cumulative NH3 emission throughout the period of measurement decreased by 71.4% and 74.8% in the AP and APB treatments. Also, APB treatment reduced ammonia emission by 11.9% compared to AP treatment. The present study clearly showed that acidification and biochar can reduce ammonia emission from pig slurry application, and pig slurry application with acidification and biochar exhibited potential effects in feed value, NUE, and reducing N losses from pig slurry application through reduction of NH3 emission.

The objective of this study was to prove the effect of pig slurry application with charcoal on nitrogen use efficiency (NUE), feed value and ammonia (NH3) emission from maize forage. The four treatments were applied: 1) non-pig slurry (only water as a control), 2) only pig slurry application (PS), 3) pig slurry application with large particle charcoal (LC), 4) pig slurry application with small particle charcoal (SC). The pig slurry was applied at a rate of 150 kg N ha-1, and the charcoal was applied at a rate of 300 kg ha-1 regardless of the size. To determine the feed value of maize, crude protein, dry matter intake, digestible dry matter, total digestible nutrient, and relative feed value were investigated. All feed value was increased by charcoal treatment compared to water and PS treatment. Also, the NUE for plant N was significantly higher in charcoal treatments (LC and SC) compared to PS treatment. On the other hand, there is no significant difference for feed value and NUE between LC and SC. The NH3 emission was significantly reduced 15.2% and 27.9% by LC and SC, respectively, compared to PS. Especially, SC significantly decreased NH3 emission by 15% compared to LC. The present study clearly showed that charcoal application exhibited positive potential in nitrogen use efficiency, feed value and reducing N losses through NH3 emission.

드론은 현재 산업의 각 분야에서 사용되고 있으며, 농업분야에서도 활발히 사용되고 있다. 특히, 초고 령 사회에 진입한 농촌과 농업분야에서 드론은 매우 효율적인 방제장비로 각광받고 있다. 드론방제기 는 운용비용이 다른 방제기에 비해서 매우 낮으며 구입비용 또한 그리 높지 않다. 한 단위의 방제면적 을 방제하기 위하여 투입되는 구입비용과 운용비용을 모두 고려하였을 때 가장 효율적인 방제기는 고 정익방제기와 드론이라 불리는 멀티콥터형 방제기이다. 고정익방제기에 소요되는 높은 운용비용과 탑 승조종사의 인건비를 고려한다면 우리나라에서 현실적으로 효율적인 방제기라 볼 수 없으며, 조종사가 탑승하지 않는 드론방제기가 매우 효율적인 방제기라고 할 수 있다. 현재 농업분야에서 방제작업에 활 발히 쓰이고 있는 드론방제기는 높은 비용효율성으로 인하여 많은 농민들에게 선호되는 방제기로 선택 되고 있다.

Smart farm is a breakthrough technology that can maximize crop productivity and economy through efficient utilization of space regardless of external environmental factors. This study was conducted to investigate the optimal growth and physiological conditions of Chinese matrimony vine (Lycium chinense) with LED light sources in a smart farm. The light source was composed of red+blue and red+blue+white mixed light using a LED system. In the red+blue mixed light, red and blue colored LEDs were mixed at ratios of 1:1, 2:1, 5:1, and 10:1, with duty ratios varied to 100%, 99%, and 97%. The experimental results showed that the photosynthetic rate according to the types of light sources did not show statistically significant differences. Meanwhile, the photosynthetic rate according to the mixed ratio of the red and the blue light was highest with the red light and blue LED ratio of 1:1 while the water use efficiency was highest with the red and blue LED ratio of 2:1. The photosynthetic rate according to duty ratio was highest with the duty ratio of 99% under the mixed light condition of red+blue+white whereas the water use efficiency was highest with the duty ratio of 97% under the mixed light of red+blue LED. The results indicate that the light source and light quality for the optimal growth of Lycium chinense in the smart farm using the LED system are the mixed light of red+blue (1:1) and the duty ratio of 97%.

본 연구의 목적은 폐쇄형 식물생산시스템에서 세가지 혼합 LED와 형광등에서 자란 적치마 상추의 생육과 광 이용효율을 비교하는 것이다. 18일간 육묘한 적치마상추 묘를 적색(R, 655nm), 청색(B, 456nm), 녹색(G, 515nm), 백색(W, 456nm + 558nm)의 혼합 LED(R:B=8:2, R:W:B =8:1:1, R:G:B=8:1:1)와 형광등이 설치된 폐쇄형 식물생산시스템에 정식하였다. 형광등에서 자란 상추는 모든 LED 처리에 비해 유의적으로 높은 엽형지수를 보였다. 지상부와 지하부 생육에서 LED 처리간 유의적 차이를 보이지 않았으나, 모든 LED 처리가 형광등에 비해 약 34% 지상부 생체중의 증가를 유도시켰다. 한편, 정식 후 4주차에 형광등의 총 소비 전력은 145kW인 반면, LED 처리구들에서 형광등의 약 1/3배인 54kW를 나타냈다. LED 처리구들의 건물중에 대비한 광 이용 효율은 약 34mg/W였으며, 이는 형광등 보다 약 3.5배 높은 값이었다. 결론적으로, 본 연구는 식물 생산 시스템에서 적절한 조합의 LED 조사는 형광등에 비해 상추 생장을 증진시킬 수 있으며 추가적으로 에너지 절감을 통해 광 이용효율도 극대화 할 수 있음을 보여주었다.

본 연구는 홍수기 유량측정의 어려움을 극복하고자 물 과 비접촉식으로 유속을 측정하여 유량을 산정하는 전 자파표면유속계(microwave water surface current meter, MWSCM)의 성능개선 제품인 범용 MWSCM에 대하여 소개하고자 하였다. 기존에 사용 중인 MWSCM은 홍수 용으로써 연중 활용도가 낮아 이것의 이용성을 높이고 자 성능을 개선하였다. 유속측정 범위를 확장하여 평∙ 갈수기에도 하천 유량측정이 가능하게 하였다. 즉 기존 홍수용 MWSCM의 유속측정 범위가 0.5~10.0 m s-1이 었던 반면, 금번에 개발된 범용 MWSCM은 0.03~20.0 m s-1로 홍수기 및 평수기 측정이 가능하도록 성능을 개선하였다. 이를 위해서 사용주파수의 변경(10 GHz → 24 GHz), 안테나 및 송수신부 회로가 새롭게 설계 제작 되었다. 이와 더불어 기존 홍수용 MWSCM 사용자들의 개선요구사항-기기 경량화, 유속 안정화, 자체점검기능, 저전력, 방수 및 방습-을 파악하여 반영함으로써 현장에 서 유량을 측정하기에 용이한 기기로 개발하였다.

Water scarcity around the globe and climate change challenges has forced the researchers to develop alternative production systems with higher water use efficiency. Direct seeded rice is the emerging water saving rice production system having higher water use efficiency. Field experiment was conducted to assess the role of different mulch systems in improving water use efficiency and productivity in direct seeded and transplanted rice. Three different rice production systems viz., transplanted rice with continuous flooding, two weeks continuous flooding after transplanting and direct seeding with supplemental irrigation only were evaluated under two ground cover systems i.e., plastic and straw mulching with no mulch taken as control. Super Basmati was used as experimental material. Continuously flooded transplanted rice with plastic mulching resulted in higher paddy yield (4.04 t ha- 1 ); while performance of no mulch direct seeding remained poor in this regard. Two weeks flooded transplanted rice with plastic mulching followed continuous flooding in paddy yield (3.94 t ha- 1 ). Continuously flooded transplanted rice with plastic mulching observed substantial improvement in yield related attributes such as panicle length, number of grains per panicle and 1000 grain weight. Plastic mulching improved the productivity and water use efficiency of transplanted as well as direct seeded rice. Higher water use efficiency was observed in direct seeded rice with plastic mulching as it was grown on supplemental irrigations. In crux productivity and water use efficiency of transplanted and especially direct seeded rice can be improved by using plastic film as mulch in current scenarios of water shortage. Key Words: mulching, rice production systems, water use efficiency, productivity

펄라이트 자루재배시 일중 관수마감시각을 달리함으로써 최적 생장을 유지하면서도 용수이용효율(WUE)과 비료이용효율(FUE)을 높이기 위해 실험을 실시하였다. 관수마감시각에 따라 일몰 1시간 전부터 4시간 전까지 4단계로 나누어 처리한 결과, 배지 내 수분함량은 마감시각이 늦을수록 많은 경향을 나타냈다. 최종 생육은 일몰 4시간 전 처리구에서 약간 낮은 경향을 보이기는 했으나, 통계적 유의차는 보이지 않았다. 상품수량은 일몰 1시간 전 및 2시간 전에서 가장 많았고, 4시간전에서 가장 적었다. 관수마감시각 처리별 128일 동안의 급액량을 조사한 결과, WUE와 FUE는 일몰마감 1시간 전 처리구에서 가장 낮았고, 3시간 전 처리구에서 가장 높았다. 식물생육, 수확량 및 WUE와 FUE 등의 면에서 일몰 4시간 전에 관수를 중단하는 것은 바람직하지 않으며, 2~3시간 전에 마감하는 것이 좋을 것으로 사료된다.

Forage production and water use efficiency (WUE) of Lucerne were investigated in three varieties at different water availabilities. Forage production decreased with the severity of soil water availability. At 50% field water capacity (FWC), forage production dropped but in two varieties, Algonquin and Longdong, was still high and from 75%FWC to 50%FWC, forage production in Longdong decreased at the least rate. The greatest leaf WUE was observed in Longdong at all soil water availabilities. From 75%FWC to 50%FWC, it increased in Longdong and Xinjiangdaye, but decreased in Algonquin. With the severity of water deficit, δ¹³C value increased in all three varieties. At the same water availability, the greatest value was observed in Longdong. It suggested that moderate water stress can improve WUE in Lucerne. Longdong is to some extent more efficient in water use and may be more drought-tolerant with more steady production at moderate water deficit.

敎育人的資源部는 2000년 12월 30일, 2001년도부터 적용되는 한문 교육용 기초 한자 1,800자 調整案을 확정 공표하였다. 교과용 도서 편찬에서 인명, 지명 등 고유명사는 이와 관계없이 지도할 수 있고, 1,800자 이외에 1할 범위 내의 追加字를 허용하고 있으므로, 현실적으로는 2,000자 이상의 한자가 필요하다는 것을 인정한 셈이다. 이 연구는 한자 학습의 효율성을 提高할 수 있는 방법을 제시하여, 학습자로 하여금 체제적으로 한자를 익힐 수 있게 하는 실용적인 목표를 달성하고자 한 것이다. 한자 학습의 어려움은 주로 字數가 많다는 것과, 字形이 복잡하다는 것으로 歸結된다. 자수의 문제는 일상생활에 필수적인 한자를 選別해서 우선적으로 학습하는 방법으로, 자형의 문제는 구조 분석을 통한 類別 학습 방법으로 해결할 수 있다고 보았다. 『한문 교육용 기초 한자 1,800자 조정 백서(교육인적자원부, 2001.)』의 「교육용 한자 조정을 위한 기초 자료를 참조하여, 검토 대상 한자 4,979자 중, 14점부터 2점까지의 한자 3,061자를 表題字로 삼아 해당 한자마다 점수를 倂記하되 중학교용에는 M(middle-school의 이니셜)자를, 고등학교용에는 H(high-school의 이니셜)자를 덧붙여 두어서 학습 優先順位를 판단하는 기준을 삼을 수 있도록 함으로써 자수의 문제를 해결하고자 하였다. 출현 頻度가 높은 한자부터 학습하는 방법은 수준별?능력별 학습량 조절에도 적용될 수 있을 것이다. 자형의 문제는 자형 분석 방법과 字索 결합 유형 및 形聲의 원리를 활용하는 방안을 제시함으로써, 복잡한 자형을 구조화하고 단순화하여 이해하게 하는 방법으로 해결하고자 하였다. 類別 학습의 장점을 살리되, 종류별로 모으는 기준을 部數와 聲符의 양대 기준으로 바꾸어, 부수 및 성부를 중심으로 각각 소속 한자들을 점수와 함께 정리하여, 여러 가지 방법들이 종합적으로 활용될 수 있도록 적용 방법과 함께 예시하였다. 이 논문에서 제시하는 방법은, 따로따로 또는 부분적으로 활용되어온 기존의 원리들을 전체적이고 綜合的으로 충실히 적용하고자 하는 것이기 때문에 생소하지 않고 간편하며 부분적인 방법들의 단점을 상호 보완할 수 있다. 부록으로 제시된 자료들에 여러 가지 정보를 추가하면, 더 깊이 있고 창의적인 학습이 가능할 것이다.

Seasonal changes in the CO2 fixation rate and water-use efficiency in the leaves of six evergreen and two deciduous broad-leaved tree species on Jeju Island, Korea, were measured using a portable photosynthesis analyzer, to identify which species are most efficient in taking up CO2 from the air. The CO2 fixation rate was high in the deciduous species in spring and summer and decreased in fall, whereas it was high in the evergreen species in summer and fall and decreased in winter. The rate remained high in the deciduous tree Prunus yedoensis from spring to fall (> 7.1 μmol CO2/m2/s) and in two evergreen trees, Castanopsis cuspidata var. sieboldii and Cinnamomum camphora, in summer and fall (7.0 9.9 μmol CO2/m2/s). Therefore, these tree species fix atmospheric CO2 effectively. The water-use efficiency was higher in evergreen species than in deciduous species regardless of the season. Exceptionally, it was high in the deciduous species Zelkova serrata in spring and summer (> 100 μmol CO2/mol H2O), suggesting that Z. serrata is a useful tree for dry conditions due to its tolerance of water stress. The regressions of the CO2 fixation rate versus the evaporation rate and stomatal conductance were linear and non-linear, respectively. This suggests that the stomatal activity of leaves plays an important part in CO2 fixation of plants. In conclusion, C. cuspidata var. sieboldii, C. camphora, and P. yedoensis should be planted along roads or in urban spaces for the greening of cities and mitigation of CO2 concentrations in the air.

The study measures the resource use efficiency of diesel based power generation in the Maldives and analyses factors which influence efficiency levels. Stochastic frontier analysis (SFA) technique is applied to data on 30 plants over two year period from 2016 to 2017. The study finds that technical efficiency scores varies from 0.44 to 0.98 across power plants. About 33 percent of the plants have scores below the mean technical efficiency score of 0.87. Empirical results indicate ownership and use of solar photovoltaic (PV) have an influence on improving efficiency levels. Privately owned power plants in resort islands obtained higher technical efficiency scores compared to public and community owned power plants. This is a significant finding as the first study that used power plants in tourist sector in a comparative study. Size of the power plants was not found significant, but relatively small installed capacities can also be efficient. This finding is important because in many inhabited islands installed capacities remain oversized compared to the load. The benchmarking exercise offers model power plants that are relatively efficient, for other power plants and policy makers in small islands to learn from.