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.

Pyrolysis fuel oil (PFO) is used for the manufacturing of high-purity pitch for carbon precursor due to its high carbon content, high aromaticity, and low heterogeneous element and impurity content. Pitch is commonly classified with its softening point, which is most considerable physical property affecting to various characteristics of the carbon materials based on pitch, such as electrical and thermal conductivity, mechanical strength, and pore property. Hence, the softening point should be controlled to apply pitch to produce various carbon materials for different applications. Previous studies introduce reforming process under high pressure and two step heat treatment for the synthesis of pitch with high softening point from PFO. These methods lead to a high process cost; therefore, it is necessary to develop a process to synthesize the pitch with high softening point by using energy effective process at a low temperature. In this study, waste polyethylene terephthalate (PET) was added to control the softening point of PFO-based pitch. The pitch synthesized by the heat treatment with the addition of PET showed the softening point higher than that of the pitch synthesized with only PFO. The softening point of PFObased pitch synthesized at 420 °C was 138.3 °C, while that of the pitch synthesized by adding PET under the same process conditions was 342.8 °C. It is proposed that the effect of the PET addition on the increase in the softening point was due to the radicals generated from thermal degradation of PET. The radicals from PET react with the PFO molecules to promote the polymerization and finally increase the molecular weight and softening point of the pitch. In addition, activated carbon was prepared by using the pitch synthesized by adding PET, and the results showed that the specific surface area of the activated carbon increased by the addition of PET. It is expected that the pitch synthesis method with PET addition significantly contributes to the manufacture of pitch and activated carbon.

This study was carried out to evaluate the forage yield and feed value of winter crops such as Italian ryegrass (IRG), oat, rye, barley, and hairy vetch. Forage crops were sown on 15 th October 2018 in a paddy field after harvesting rice and forage crops were harvested at two times of 25 th April 2019 and 18 th May 2 01 9. T he h ighest d ry m atter (DM) y ield w as h arvested f rom r ye among t he five species of forage crop on 18 th May. DM yield of all forages was increased 14.4% on 18 th May compared to 25 th April. The highest yield of crude protein (CP) was obtained from hairy vetch on 25 th April, whereas it was decreased (38.1%) on 18 th May. Moreover, the highest total digestible nutrient (TDN) yield and relative feed value (RFV) was harvested respectively from rye and hairy vetch on 25 th April. Delay of harvest time considerably increased DM yield but significantly decreased CP and RFV. In conclusion, rye was the best source of DM and TDN and hairy vetch was the high-quality feed. Rye harvested on 25 th April is the proper forage for resolving Korea’s problem of insufficient forage yield.

이끼의 분쇄번식 시, 가장 적합한 배양토, 광, 온도를 구명 하기 위해 날개양털이끼(Brachythecium plumosum)와 쥐꼬리이끼(Myuroclada maximowiczii)를 이용하여 실험을 수행하였다. 실험 개시 4주 후에 사진을 찍어 Photoshop에서 이끼 면적과 녹색 평균값을 구하여 이끼의 생육 정도를 나타내었다. 배양토의 경우, 두 이끼 모두 다스란 상토에서 생육이 가장 좋았고, 상토:마사토(50:50), 원예상토, 마사토:피트모스(50:50) 에서는 비슷한 수준이었다. 버미큘라이트 단용에서는 생육이 부진하였다. 광도실험에서는 날개양털이끼는 25umol･m-2･s-1 에서 100umol･m-2･s-1까지 광도가 높아질수록 생육이 조금씩 좋아지는 경향이었으나, 쥐꼬리이끼는 3개의 광환경에서 비슷한 수준이었다. 온도 실험에서는 두 이끼 모두 23℃에서 면적과 녹색값이 가장 높아 생육도 좋았다. 이러한 결과를 종합 하면, 건조한 이끼를 분쇄하여 번식할 때, 배양토로는 보습력이 좋은 다스란 상토나 원예용 상토가 무난하며, 광도는 25~100umol･m-2･s-1 범위, 온도는 20~23℃가 적당할 것으로 판단된다.