• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.186-186
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• 2017

Relay intercropping system of direct seeded rice and winter cereal is labor saving cultivation and has high land use efficiency in Japan. In this system, rice seeds are direct seeded into inter-row space of winter cereals (wheat or barley) in March or April. If the direct seeding of rice is conducted before stem elongation phase or using suitable seeder, these are little effect to yield of winter cereals. Though the seeds are generally thiuram treated, it's a matter that seedling establishment rate (SER) of direct seeded rice is low and unstable. The cause of low SER has not been revealed. In present study, with the aim to reveal causes of low SER, we conducted experiments and investigated the SER, and analyzed some factors that might affect SER. Experiment1: In 2015, 2016, we buried rice seeds underground, and investigated the transition of the seed survival rates (SSR). Seeds were thiuram-treated or non-treated. In 2 periods, SSR of thiuram-treated seeds were significantly higher than non-treated seeds. In 2016, thiuram-treated seeds were high in SSR (almost 75%) at April 30th, but low SER (10~27%) after harvest of winter cereals. Therefore, almost all of seed death might have been happen after germination. Analysis 1: We investigated the SER and cultivation conditions in Ibaraki pref. for several years. Meteorological factors were referred from the nearest point of AMeDAS. From mean temperature (MT) among 5days after and before the day, we divided the period of seeding ~June 20 to phase1~4. We defined each phase as below; Phase1: $MT{\leq}10^{\circ}C$, Phase2: $10^{\circ}C<MT{\leq}15^{\circ}C$, Phase3:$15^{\circ}C<MT{\leq}20^{\circ}C$, Phase4: $MT>20^{\circ}C$. We analyzed the correlation of SER and meteorological factors by each phase. Total number of days in phase 1~4 was significantly negative correlated with SER. In phase1, total rain fall and number of soil wetting days were significantly negative correlated with SER. In phase2~4, only MT was significantly positive correlated with SER. This result suggested that rainfalls in phase1 declined seed vigor to emergence from soil surface, by repeated water absorption and re-dry. From these present studies, it was suggested that one of factors of low SER of direct seeded rice in relay intercropping system is changing of water condition by rainfalls in phase1 ($MT{\leq}10^{\circ}C$). To improve SER, it's necessary to consider something seed treatments such as prevent water absorption during phase1. However, 58~60% of seeds seemed to die during May. It's suggested that, if seeds are thiuram treated, almost all of seeds can germinate underground, but the seed vigor to emergence from soil surface are insufficient. Further studies are needed to reveal the rest causes that is happening during emergence from soil surface.

• 환경생물
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• 제34권3호
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• pp.169-176
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• 2016

본 연구는 중북부지방 적응성 자운영 선발 및 수집 계통간 형태적, 유전적 근연관계를 분석한 것으로서 총 수집된 16개 자운영 계통 중 파주종은 엽각이 적고, 지하부의 발육이 좋아 형태적 형질이 월동에 적합한 초형이었다. 또한 구례 수집종은 개화기가 타 수집종에 비해 일주일 가량 빨랐다. 유전적 근연관계를 검정하기 위해 8개 primer 조합으로 AFLP를 실시한 결과 총 579개의 밴드를 얻었으며, 이 중 polymorphism을 갖는 밴드는 61.54%인 336개 밴드였다. AFLP 데이터를 이용해 군집분석을 실시한 결과 계통 간 유사도 지수는 0.826~0.939 사이의 값을 가지며, 구례와 파주 수집종은 타 수집종과 유전적 유사도에서 비교적 큰 차이를 보였다.

• 농업과학연구
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• 제19권1호
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• pp.65-78
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• 1992

본(本) 연구(硏究)는 당진지방(唐津地方)의 해성(海成)실트질 점성토(粘性土)를 채취하여 물리적(物理的) 실험(實驗) 및 삼축압축시험(三軸壓縮試驗)을 실시하고, 그 시험결과로 쌍곡선식(雙曲線式) 매개상수(媒介常數)를 구한 후, 쌍곡선식(雙曲線式) 모형(模型)에 의한 응력일변형관계(應力一變形關係)를 검토하여 점성토(粘性土)의 응력일변형(應力一變形)을 추정하여 다음과 같은 결과(結果)를 얻었다. 1. 건조밀도(乾燥密度) 및 함수비(含水比)의 증가(增加)에 따른 탄성계수(彈性係數)는 건조밀도(乾燥密度)에 비례하고, 함수비(含水比)는 반비례하였다. 2. 쌍곡선식(雙曲線式) 모형(模型)에 가장 많은 영향을 미치는 인자는 적압력(積壓力)과 건조밀도(乾燥密度)이었고, 점착력과 내부마찰각(內部摩擦角)은 이보다 적은 영향(影響)을 타나났다. 3. 통계적(統計的) 방법(方法)의 추정치를 쌍곡선식(雙曲線式)에 의한 추정치와 비교하였으나, 통계적(統計的) 추정치가 쌍곡선식(雙曲線式) 모형(模型)에 의한 추정치보다 낮게 나타났다. 4. 많은 그림과 계산과정(計算過程)을 단순화하여 시간적 노력을 줄이는 실용적(實用的) 전산(電算)프로그램을 작성하였으나, 입력되는 기초정수(基礎定數)의 시험오차(試驗誤差)를 없애는 것이 중요하다.

• 한국지역지리학회지
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• 제3권1호
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• pp.99-113
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• 1997

본 연구는 영농을 목적으로 도시에서 농촌으로 거주지를 이동하는 귀향농가의 발생이유와 그들의 적응과정을 미시적 사례분석을 통해 밝히고자 하였다. 1980년대 이전의 귀향농가 발생은 가족 부양이나 도시적응실패 등의 사회적 원인이었지만 최근의 귀향농가 발생은 재배작물의 수익성을 고려한 경제적 원인이 더 크게 작용된 결과이다. 귀향농가의 발생유형은 이촌 후 고향으로 귀농하는 경우가 많지만 직접적인 영농경험이 없는 도시거주자가 수익성을 고려한 특정작물의 재배를 목적으로 귀농하기도 한다. 특히 최근의 귀향농가는 농업경영형태에 있어서 소유농지가 전혀없이 순수 임차에 의해 발생되기도 하며 농지의 매입보다 임차지의 확대를 통해 경영규모를 확대하고 있다. 그런점에서 귀향농가의 증가는 산업화 이후 노동력부족에 따른 농촌의 경지이응을 저하를 완화시키는 방안이 될 수 있다. 현재까지는 귀향농가의 비중이 미약한 것이 사실이지만 최근들어 증가 추세에 있고 귀향하는 경영주가 젊은 연령층이므로 이들에 의한 파급효과는 기대해 볼 수 있다. 따라서 과소지역으로서의 농촌문제 해결을 위해서는 귀향농가를 위한 적극적인 대책이 모색되어야 하는데 이들의 성공적인 정착을 위해서는 자금지원이나 영농조건의 개선도 중요하지만 교육여건과 생활시설의 개선 등 하부구조의 확충이 무엇보다 절실하다.

• 한국토양비료학회지
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• 제39권5호
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• pp.298-302
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• 2006

비닐피복작물 재배시 시비효율 증대 및 생력시비기술 확립을 위하여 파종과 동시에 시비가 가능한 토중시비기를 개발하였고 개발된 파종기와 시비기를 이용하여 1999년부터 2000년까지 시비간격 30 cm, 시비깊이 15 cm, 파종간격 25 cm로 배수가 양호한 사양토에서 땅콩을 재배한 후 작업정도, 토양화학성, 양분흡수량 및 수량성에 미치는 영향을 평가하였다. 땅콩의 파종 소요시간은 인력($173hr\;ha^{-1}$)에 비하여 90% 이상 노력절감 효과가 있었으나 출현일수는 4일정도 지연되었으며 입모율은 관행구에 비하여 11~18% 낮았다. 시험 전 토양에 비하여 시험 후 토양의 총질소 함량은 증가한 반면에 유기물, 유효인산 및 치환성 칼륨함량은 감소되었으며 토양의 질산태질소 합량은 생육초기에서 중기까지 국소시비구에서 시비량이 많을수록 증가하였다. 땅콩의 질소흡수량은 근류균에 의한 자체 고정량이 많아 시비방법 및 시비량별 큰 차이가 없었으나 인산 및 칼리흡수량은 국소시비 70%, 100%구에서 높은 경향을 나타냈다. 땅콩의 생장속도는 시비방법별 공히 파종 후 120일에 가장 많이 증가되었고 관행시비구와 국소시비 70%구에서 생육후기까지 증가폭이 크게 나타났으며 국소시비 70%구는 협수가 많고 협실비율 및 완숙립중 비율이 높아 종실중이 관행시비구 $3,150kg\;ha^{-1}$에 비하여 4% 증수되었다.

• 사물인터넷융복합논문지
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• 제8권2호
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• pp.35-40
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• 2022

농업환경에서 농약방제는 농업인에게 작업 위험성과 높은 노동력을 요구한다. 무인항공기를 활용한 농약방제는 기후, 토지형태, 무인항공기의 특성에 따라 효율성이 다르게 나타난다. 따라서, 살포조건과 환경조건을 고려한 효율적인 무인항공기 농약방제 방안이 요구된다. 본 논문은 작물별 살포조건과 환경정보를 고려한 농업용 무인항공기 기반의 효율적인 농약 방제 시스템을 제안한다. 감수지 부착 후 고도 및 속도 변화에 따른 농약 낙하균일도 측정 및 작물 성장조건 변화에 따른 수관내부 약제 침투율 측정 실험을 통해 제안하는 모델의 효과성을 보였다. 실험결과, 무인항공기의 높이가 지면과 가까울수록 작물에 고르게 살포되지만 안전이 고려된 2m이상이 높이와 평균 2m/s의 속도에서 가장 방제효과가 적합하였다. 제안하는 방제 시스템은 농업환경에서의 다양한 무인항공기 활용 기반 지능형 서비스 개발에 도움을 줄 것으로 기대한다.

• 한국지역사회생활과학회지
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• 제15권4호
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• pp.33-44
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• 2004

The characteristics of social and cultural life in agricultural regions in Korea encompass several positive external effects: quality of food services, awareness of environmental conservation, aesthetic enjoyment of nature and so on. The objectives of this study were (1) to measure the awareness among Korean youth of the benefits of rural life; (2) to delineate the differences between rural and urban youth; and (3) to promote an awareness of the importance of the social benefits of living in the country. To fulfill these purposes, a field survey method was used. The subjects were 211 third grade students from middle schools in rural and urban regions in Korea. The statistical methods used for this data included frequencies, percentages, 1-tests, etc. The study generatedconclusive findings about viewpoints toward the natural environment, urban and rural social culture, and perceptions of economic status. It showed significant differences between rural and urban youth's awareness of ideas such as'green field supply','labor power supply'and 'biodiversity conservation'.

• 수산경영론집
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• 제27권1호
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• pp.67-90
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• 1996

As an important factor of capitalism economics, price of commodities represents a certain country's economic index. For having correct price policy, there should be an appropriate mechanism to make and use systematic statistical data on price. Price statistics are made by indexes and price indexes are categorized into producer price index(PPI) and consumer price index(CPI). The Bank of Korea is publishing producer price index every year, but the producer price index contains some problems. These include as follows : (a) the impractical selection of fisheries products sample (b) uncorrect measure of aquatic products weights (c) investigating sample places. This study try to substitute producer price index of aquatic products and change construction of fisheries producer price index with experimental research on representative fisheries, weight of each fisheries, and suitability of investigating sample places. It is possible to improve practical fisheries producer price index with the results of this research. The findings are as follow. (a) It will be helpful for the government to make the fisheries price policy. (b) It can be used to understand trends of accurate price and price increase of aquatic products, and it's possible to compare with it other industrial indexes including the mining, agricultural, and manufacturing industry and understand relative price movement. (c) When free sales systems of fisheries products as expected, it will be helpful to analyze price movement of producing fisheries cooperatives, producing fisheries market and consuming fisheries market, analysis of market, and formation and consideration of budget. (d) It can be an important index to determine labor wage.

• Journal of Biosystems Engineering
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• 제26권2호
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• pp.131-140
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• 2001

This study was conducted to develop a garlic separator which could to reduce the labor in preparation of seeding. After consideration of the design criteria of a garlic separator such as no additional conveying device, simple construction and operation, enhancement of separating efficiency, reduction of damage, degree a rotating corn type garlic separator was designed. The effects of design parameters such as height and angle of the inner and outer corns, rotating speed of inner corn on the separating performance of the prototype were estimated. In performance was compared with manual work. The results are summarized as follows. 1. Garlic bulbs were separated by a spiral movement in the gap between inner rotating corn and outer fixed corn. At constant feed rate of garlic bulbs, the capacity of garlic separation increased with increase of rotating speed of inner corn. Especially, the capacity was very high at the rotating speeds of 300 and 400rpm. 2. The damage degree of separated garlics increased with rotating speed of corn within 10%. Above 300rpm, separability of Uisung garlic was about 100% and incomplete separation of Namdo garlic was within 2%. 3. The capacity of prototype garlic separator developed in this study was 30 times as large as that of human being.

• Journal of Biosystems Engineering
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• 제15권4호
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• pp.328-338
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• 1990

The objective of this study was to develop automatic systems of nutrient solution management for optimal nutrient solution environment and labor saving in water culture which enables factory crop production. In this study, an automatic control system and its driving program are developed to prepare, supply, and recover nutrient solution and to keep the optimal solution concentration level using microcomputers. Based on this study, the following conclusions are obtained: 1. The concentration measured by the system using oscillating circuit designed and built in this study, gave good agreements with the actual nutrient solution. 2. In water culture, the period of 12 hours for measuring concentration, pH, and temperature of the nutrient solution was optimum. Addition of control solution due to the decrease of the nutrient solution concentration is required in every 3 to 5 days. 3. It is estimated that the period of the whole solution change is 15 days, however, further research is needed to assure it. In addition, this period must be shortened in the future. 4. Both the hardware and software of the developed optimal nutrient solution control system in the water culture are working very well, however, it is necessary to develop a more economical one-chip micro controller to substitute for the microcomputer.