• 제목/요약/키워드: reading response

검색결과 203건 처리시간 0.022초

지렁이분 시비가 잡초의 침입과 벤트그라스 잔디초지에 미치는 영향 (Influences of Worm Casting Organic Fertilizer on Weed Invasion on the Creeping Bentgrass Sward)

  • 박성준;조남기;강영길;송창길;현해남;조영일
    • 한국초지조사료학회지
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    • 제25권3호
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    • pp.211-216
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    • 2005
  • 본 시험은 제주지역에서 지렁이분 시비량 차이(0, 150, 300, 450, 600kg/10a)에 따른 한지형 잔디(Creeping bentgrass)의 식생의 변화를 검토하고, 지렁이분 적정시비량을 구명하기 위하여 2004년 3월 21일부터 7월 10일까지 시험하였다. 초장은 무비구에서 지렁이분 600kg/10a까지 16.7cm에서 20.2cm로 커졌으나, 지렁이분 450kg과 600kg/10a 시비구에서는 유의한 차이가 없었다. 근장, 엽록소는 초장반응과 비슷한 경향이었다. 엽중, 근중은 무비구에서 각각 788kg, 1,515kg/10a이었으나, 지렁이분 시비량이 증가함에 따라 점차적으로 증가되어 450kg과 600kg/10a 시비구에서는 엽중은 1,191kg에서 1,202kg/10a로, 근중은 2,060kg에서 2,141kg/10a으로 증수되었으나, 지렁이분 450kg과 600kg/10a 시비구간에는 유의한 차이가 없었다. 무비구에서 지렁이분 시비량이 600kg/10a로 증가함에 따라 잔디의 점유율은 $92.3\%$에서 $97.0\%$로 증가되는 반면, 잡초는 $7.7\%$에서 $3.0\%$로 감소되었다. 무비구에서 잔디의 밀도는 $97.2\%$, 잡초는 $2.8\%$ 이었으나, 지렁이분 시비량이 증가함에 따라 점차적으로 증가되어 600kg/10a 시비구에서 잔디의 밀도는 $98.1\%$로 증가되었고, 잡초의 밀도는 $1.9\%$로 감소되었다. 지렁이분 시비량이 증가함에 따라 침입잡초는 16.5종에서 12.0종으로 감소되었다. 우점잡초의 변동은 무비구에서 명아주, 바랭이, 여뀌순위였고, 지렁이분 150kg\10a 시비구에서는 쇠비름, 바랭이, 여뀌 순위로, 450kg/10a 시비에서는 여뀌, 새포아풀, 바랭이 순위로, 600kg/10a 시비구에서는 여뀌, 바랭이, 쇠비름 순위였다. 이상의 시험결과를 보아 제주지역에서 Creeping bentgrass의 점유율과 밀도를 최대로 증대시킬 수 있는 지렁이분 적정시비량은 10a당 $450\~600kg$으로 추정할 수 있다.

모래입경이 Creeping Bentgrass 잔디 초지의 식생에 미치는 영향 (Effect of Sand Particle Sizes on Turf Vegetation of Creeping Bentgrass)

  • 박성준;조남기;강영길;송창길;조영일
    • 한국초지조사료학회지
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    • 제25권3호
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    • pp.205-210
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    • 2005
  • 본 시험은 모래입경의 차이(0.3-0.5, 0.5-0.8, 0.8-1.0, 1.0-1.5 및 1.5-2.0mm)에 따른 한지형 잔디의 식생의 변화를 구명하기 위하여 2004년 3월 21일부터 7월 9일까지 시험하였다. 초장은 모래입경 0.3-0.5mm에서 22.5cm로 커졌으나, 모래입경이 굵어짐에 따라 초장은 점차적으로 작아져서 모래입경 1.5-2.0mm 처리구에서 초장은 19.7cm였다. 근장 및 엽록소 함량은 초장 반응과 비슷한 경향이었다. 엽중과 근중은 모래입경 0.3-0.5mm 처리구에서 각각 1,485kg/10a, 2,182kg/10a로 수량이 증가하였으나, 모래 입경이 굵어짐에 따라 점차적으로 감소하여 1.5-2.0mm 처리구에서 엽중은 1,040kg/10a, 근중은 1,676kg/10a로 수량이 감소하였다. 모래입경이 0.3-0.5mm에서 1.5-2.0mm로 굵어짐에 따라 잔디의 피도는 $98.7\%$에서 $97.0\%$로 낮아졌으나, 잡초의 피도는 $1.3\%$에서 $3.0\%$로 증가되었다. 모래입경이 0.3-0.5mm에서 잔디의 밀도는 $98.8\%$, 잡초의 밀도는 $1.2\%$였으나, 모래입경이 1.5-2.0mm로 증가됨에 따라 잔디의 밀도는 $98.1\%$로 낮아졌고, 잡초의 밀도는 $1.9\%$로 증가되었다. 모래입경이 0.3-0.5mm에서 1.5-2.0mm로 굵어짐에 따라 잡초의 종류는 11종에서 15종으로 증가되었다. 잡초의 우점순위는 0.3-0.5mm와 0.5-0.8mm 모래에서 각각 쇠비름, 토끼풀, 방동사니, 0.8-1.0mm 모래에서 토끼풀, 쇠비름, 여뀌, 1.5-2.0mm 모래에서는 쇠비름, 여뀌, 새포아풀 순위였다. 본 시험결과로 볼 때, 제주지역에서 Creeping bentgrass의 생육에 적합한 모래입경의 크기는 0.3-0.5mm인 것으로 판단되었다.

제 1, 2회 학생 과학 공동탐구 토론대회의 종합적 평가 (Summative Evaluation of 1993, 1994 Discussion Contest of Scientific Investigation)

  • 김은숙;윤혜경
    • 한국과학교육학회지
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    • 제16권4호
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    • pp.376-388
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    • 1996
  • The first and the second "Discussion Contest of Scientific Investigation" was evaluated in this study. This contest was a part of 'Korean Youth Science Festival' held in 1993 and 1994. The evaluation was based on the data collected from the middle school students of final teams, their teachers, a large number of middle school students and college students who were audience of the final competition. Questionnaires, interviews, reports of final teams, and video tape of final competition were used to collect data. The study focussed on three research questions. The first was about the preparation and the research process of students of final teams. The second was about the format and the proceeding of the Contest. The third was whether participating the Contest was useful experience for the students and the teachers of the final teams. The first area, the preparation and the research process of students, were investigated in three aspects. One was the level of cooperation, participation, support and the role of teachers. The second was the information search and experiment, and the third was the report writing. The students of the final teams from both years, had positive opinion about the cooperation, students' active involvement, and support from family and school. Students considered their teachers to be a guide or a counsellor, showing their level of active participation. On the other hand, the interview of 1993 participants showed that there were times that teachers took strong leading role. Therefore one can conclude that students took active roles most of the time while the room for improvement still exists. To search the information they need during the period of the preparation, student visited various places such as libraries, bookstores, universities, and research institutes. Their search was not limited to reading the books, although the books were primary source of information. Students also learned how to organize the information they found and considered leaning of organizing skill useful and fun. Variety of experiments was an important part of preparation and students had positive opinion about it. Understanding related theory was considered most difficult and important, while designing and building proper equipments was considered difficult but not important. This reflects the students' school experience where the equipments were all set in advance and students were asked to confirm the theories presented in the previous class hours. About the reports recording the research process, students recognize the importance and the necessity of the report but had difficulty in writing it. Their reports showed tendency to list everything they did without clear connection to the problem to be solved. Most of the reports did not record the references and some of them confused report writing with story telling. Therefore most of them need training in writing the reports. It is also desirable to describe the process of student learning when theory or mathematics that are beyond the level of middle school curriculum were used because it is part of their investigation. The second area of evaluation was about the format and the proceeding of the Contest, the problems given to students, and the process of student discussion. The format of the Contests, which consisted of four parts, presentation, refutation, debate and review, received good evaluation from students because it made students think more and gave more difficult time but was meaningful and helped to remember longer time according to students. On the other hand, students said the time given to each part of the contest was too short. The problems given to students were short and open ended to stimulate students' imagination and to offer various possible routes to the solution. This type of problem was very unfamiliar and gave a lot of difficulty to students. Student had positive opinion about the research process they experienced but did not recognize the fact that such a process was possible because of the oneness of the task. The level of the problems was rated as too difficult by teachers and college students but as appropriate by the middle school students in audience and participating students. This suggests that it is possible for student to convert the problems to be challengeable and intellectually satisfactory appropriate for their level of understanding even when the problems were difficult for middle school students. During the process of student discussion, a few problems were observed. Some problems were related to the technics of the discussion, such as inappropriate behavior for the role he/she was taking, mismatching answers to the questions. Some problems were related to thinking. For example, students thinking was off balanced toward deductive reasoning, and reasoning based on experimental data was weak. The last area of evaluation was the effect of the Contest. It was measured through the change of the attitude toward science and science classes, and willingness to attend the next Contest. According to the result of the questionnaire, no meaningful change in attitude was observed. However, through the interview several students were observed to have significant positive change in attitude while no student with negative change was observed. Most of the students participated in Contest said they would participate again or recommend their friend to participate. Most of the teachers agreed that the Contest should continue and they would recommend their colleagues or students to participate. As described above, the "Discussion Contest of Scientific Investigation", which was developed and tried as a new science contest, had positive response from participating students and teachers, and the audience. Two among the list of results especially demonstrated that the goal of the Contest, "active and cooperative science learning experience", was reached. One is the fact that students recognized the experience of cooperation, discussion, information search, variety of experiments to be fun and valuable. The other is the fact that the students recognized the format of the contest consisting of presentation, refutation, discussion and review, required more thinking and was challenging, but was more meaningful. Despite a few problems such as, unfamiliarity with the technics of discussion, weakness in inductive and/or experiment based reasoning, and difficulty in report writing, The Contest demonstrated the possibility of new science learning environment and science contest by offering the chance to challenge open tasks by utilizing student science knowledge and ability to inquire and to discuss rationally and critically with other students.

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