물 유거(Run-off)에 따른 토양유실량을 자동정량하고자 ISCO 6712 수질환경 종합측정장치를 이용하여 토양유실량 추정장치를 고안하였고, 이 장치를 통해 실시간으로 유실되는 토양량을 추정할 수 있었다. 토양유실량 추정장치는 ISCO 6712 장치에 수위계(ISCO 730), 우량계(ISCO 674) 그리고 흙탕물을 받는 저수조 내에 층위 별로 흙탕물을 자동으로 채취할 수 있는 시설을 추가하였다. 1 × 5 m2 크기, 경사 15 %의 라이시미터(lysimeter) 내 석비레(Saprolite) 토양에 옥수수를 심어 실험한 결과 2017년 1회 강우량 161.3 ㎜의 강우사상에서는 실측 토양유실량의 85.1%, 82.6 ㎜ 강우사상에서는 101.7 %의 토양량을 추정하였다.

Halitosis is a bad odor in mouth. The etiology of halitosis is multifactorial including intra-oral and extra-oral causes. It affects social interactions in many people. The aim of this study is to investigate an association between recognition group and non-recognition group by evaluating halitosis level and systemic factors. Nineteen participants who visited Department of Periodontology of Seoul National University Bundang Hospital were enrolled. Volatile sulfur a compounds (VSCs) were measured by Oral ChromaⓇ, a questionnaire was requested and oral exam was carried out in all subjects. Female is more sensitive than male for oral malodor. VSCs level of hydrogen sulfide(H2S) and methyl mercaptan(CH3SH) in male is higher than that in female. Participants who gave appeal dry mouth seem to recognize halitosis.

Recent growing about global warming has led to increase the need for low-carbon, green growth policy at the agricultural sectors and interest in the environmental-friendly and organic products. Therefore, Korea government has decided to reduce the use of chemical fertilizer at the farm field up to 40% and in order to attain this goal, promoting to grow green manure crops has been taken into positive consideration in terms of maintaining soil fertility and preventing soil loss. To this result, the acreage to cultivate green manure crops has been sharply increased from 4,000ha in 1998 to 225,000ha in 2012. Regarding environment-friendly agriculture, bulk of rice straw should be incorporated into the paddy just after harvest as soil cover materials and also green manure crops, such as chinese milk vetch, rye, Hairy vetch and so on have been recommended to be grown annually as soil cover crops. General sowing process of a certain seed crop at the farm field consists of plowing, harrowing, seeding, covering up seeds with soil in order. This process at the field has been known to take relatively long time and even not to be equal at the seeding depth. For this reasons, new seeding technology has been continuously required by farmers. Partial-tillage seeder consisting of dressing furrow and seeding parts enable to overcome germination barriers. Two soybean cultivars, ‘Taekwang’ and ‘Shingi’ were used to test the performance of newly-developed seeder and its establishment rate showed around 70 ~ 90% with given interval of embedded soybeans. Furthermore, the partial tillage technology applicable to the soybean field could reduce labor cost by 69% as well as 22% of the fuel consumption and also promote soybean productivity per unit area.

2009~2011년 동안 국내 주요 배추 재배지 5개 지역(평창, 홍천, 봉화, 무주, 제주)에서 살충제에 대한 복숭아혹진딧물의 저항성 발달 정도를 조사하고, 야외 개체군에 적용 가능한 살충제 저항성 마커를 개발하기 위해 본 연구를 수행하였다. 조사된 5개 지역 개체군 모두 여러 살충제 종류에 대하여 다양한 저항성을 보였다. 다양한 저항성을 보인 5개 지역 야외 개체군으로부터 여라 살충제에 대하여 복합적으로 저항성을 보이는 복합저항성 계통(MR)을 선발하였고, 이 MR과 모든 지역 채집 개체군에 대해 등전점전기영동과 정량염기서열분석(quantitative sequencing, QS)을 통하여 에스터레이즈 과발현과 살충제 작용점 내 돌연변이를 확인하였다. MR을 포함한 모든 야외 개체군에서 에스터레이즈의 과발현과 아세틸콜린에스터레이즈 1 유전자(ace1)의 StoF 돌연변이를 확인할 수 있었다. 넉다운 저항성 돌연변이로 잘 알려진 파라 타입 나트륨 채널 유전자(para)의 LtoF 돌연변이는 모든 지역 채집 개체군은 물론 비펜스린에 대해 3,461배 저항성을 보이는 MR에서도 발견되지 않았다. 그 외에 MtoL 돌연변이를 발견하였는데, 생물검정 결과 저항성 수준과 돌연변이 발생 빈도가 일치하였다. 따라서 생물검정 대신, 이러한 분자 마커를 활용 한다면 더 효율적으로 살충제 저항성 평가가 가능할 것이다. 이러한 분자 마커들(ace1의 StoF, para의 MtoL)은 정량염기서열분석, PCR amplification of specific alleles (PASA) 등의 진단 방법에 쉽게 응용이 가능 하고, 이러한 방법은 야외 복숭아혹진딧물 저항성 관리에 적용이 가능 할 것이다.

고랭지 경사밭의 토양보전을 위해서 고랭지 배추재배지에 애기기린초, 범의귀, 지면패랭이, 긴병꽃풀 등 4종의 지피성 동반작물의 도입가능성을 경사도 5, 15 및 30%의 라이시미터에서 평가하였다. 애기기린초를 제외한 지피성 동반작물은 배추의 생육에 영향을 미치지 않았다. 배추와 동반작물에 의한 정식 이후의 피복률 변화는 동반작물보다는 배추생장에 의해 주도되었으며, 초기의 생장속도가 빨랐던 긴병꽃풀과 애기기린초 동반작물 재배구에서 초기 피복률 상승이 빠른 반면, 고온기 생장속도가 느린 범의귀와 지면패랭이는 급속한 피복도 증가를 보이지 않았다. 각각의 동반작물의 줄기와 잎의 절단 경도는 범의귀와 애기기린초가 낮은 반면, 긴병꽃풀과 지면패랭이는 매우 높아 내답압성이 우수하였다. 지피성 동반작물과 배추는 광 및 양분 경합성은 거의 없었다. 지피성 동반작물 재배구에서 배추 수관 아래 기온 및 지온은 배추 단독구보다 각각 1℃내외, 0.5~1℃ 낮았으며, 습도는 8% 정도 높았다. 4종 지피성 동반작물을 토양보전성, 경관성, 내성, 생육 등을 고려하여 각 평가요소별 가중치를 두어 평가한 결과, 지면패랭이〉긴병꽃풀〉〉범의귀〉애기기린초의 순으로 높았고, 이중 지면패랭이가 가장 우수하였다.

Our research work aimed to evaluate cover crop effects of winter rye on soil characteristics, soil conservation, and yield productivities on potato fields with 15% slope during a fallowed period. There were two controls of bared field without any cultivation and conventional potato cultivation without winter rye. Potato cultivation increased soil pH, organic matter, available phosphate, and exchangeable cation regardless of cover crop cultivation. Sub-soil, particularly, all components of soil chemical properties showed higher value in winter rye cultivation than conventional cultivation. Higher soil density was observed on cover crop cultivation than conventional cultivation resulting from root residues of the cover crop both topsoil and subsoil. Cover crop residues positively affected plant growth and reduced the amount of soil erosion by holding the soil. Although severe soil erosion was seen in conventional cultivation, winter rye cultivation declined soil erosion by 47% during the fallow period on potato slope fields. Distinct soil bacterial communities were detected among treatments and some OTU(Operational Taxonomic Unit)s showed significantly higher abundance in winter rye treatment. Total yield and commercial rate demonstrated no significant differences while higher tuber phosphate, K+, and Mg2+ contents were observed in winter rye cultivation.

Soil microorganism activity in an agricultural field is affected by various factors including climate conditions, soil chemical properties, and crop cultivation. In this study, we elucidate the correlation between microorganism activity and agricultural environment factors using the dehydrogenase activity (DHA) value, which is one of the indicators of soil microbial activity. As a result, the various factors noted above were related to the DHA value. Annual rainfall, soil Mg2+, bacterial and fungal diversities, types of crops, developmental stages, seasons, and cultivation status were highly correlated with the DHA value. Furthermore, next-generation sequencing (NGS) analysis was used to identify that the type of crop affected soil microbial compositions of both bacteria and fungi. Soil used for soybean cultivation showed the highest relative abundance for Verrucomicrobia, Planctomycetes, and Acidobacteria but Actinobacteria and Firmicutes had the lowest relative abundance. In the case of soil used for potato cultivation, Actinobacteria had the highest relative abundance but Proteobacteria had the lowest relative abundance. Armatimonadetes showed the highest relative abundance in soil used for cabbage cultivation. Among the fungal communities, Mortierellomycota had the highest relative abundance for soybean cultivation but the lowest relative abundance for cabbage cultivation; further, Rozellomycota, Chytridiomycota, and Cercozoa had the highest relative abundance for cabbage cultivation. Basidiomycota had the highest relative abundance for potato cultivation but the lowest relative abundance for soybean cultivation.

Soil conservation management is necessary for sustainable agriculture, in highland areas, and cover crops are one of the best soil conservation methods for slopes. In this study, we evaluated the effects of alfalfa cultivation on maize production, as well as soil conservation and quality. There was an outstanding soil conservation effect with alfalfa cultivation in the fallow and maize growing seasons. In particular, alfalfa cultivation reduced soil loss by up to 98% compared with bare field. It also increased the activities of soil microorganisms and the supply of organic matter. Maize production with alfalfa cultivation showed no significant differences in yield. In conclusion, alfalfa is an advantageous perennial cover crop in highland agricultural slope areas, which can have positive effects on soil quality and conservation, as well as maize production.

고랭지 농업(해발고도 400 m이상)은 주로 해발고도가 높은 산지의 경사지에서 이루어지고 있고, 대부분 작물 재배기간이 5월부터 9월까지(5개월)로 짧아, 나머지 7개월은 토양 피복이 이루어지지 않은 상태로 있어 토양유실 가능성이 높다. 이러한 문제점을 개선하기 위해 본 연구에서 고랭지 경사도 55% 라이 시미터(Lysimeter)에서 경관성이 높은 구절초를 식재하여 토양 유실 저감 효과를 규명하였다. 관행구로 나지(Control, TC) 대비 식재 밀도에 따라 구절초 적은 그룹(T1, 40주), 구절초 많은 그룹(T2, 70주)로 하여 총 3처리를 두었다. 구절초의 재배기간 (6-10월) 피복율을 조사한 결과 대조구인 나지상태인 TC는 0% 의 피복율인데 반해 구절초 식재한 T1 처리구는 43-59%의 피복율을 보였으며, T2 처리구는 63-81%로 경사지 토양을 피복시 키는 효과가 가장 좋았다. 재배기간 평균기온의 5개월 평균은 평균기온범위는 16.1℃로 나타났으며 강우량은 1207.9 ㎜로 나 타났다. 재배기간 동안 평균적인 지표유출량 경감효과는 TC 처 리 대비 구절초 피복처리구인 T1 처리구는 71%, T2처리구는 76%로 우수하였다. 또한, 토양유실량의 경우 TC보다 T1처리구 의 경우 84%, 재색밀도가 높은 T2 처리구의 경우 98%의 토양유실 감소효과를 보였다. 따라서, 고랭지 경사지에 영년생 자원식물 중 경관성이 뛰어난 구절초를 식재함으로서 경사지 토양유실을 경감시킬 수 있고, 부가가치가 높은 고소득작물로 활용 가능할 것으로 기대된다.

Common reed (Phragmites australis) is widespread in reclaimed land and wetland habitats. Every year, the common reed produces extensive colonies by means of underground rhizomes and ground-surface stolons. From an agricultural point of view, the common reed's large biomass is a good material for supplying organic matter. However, it has not yet been studied in terms of seedling production, transplanting conditions, and decomposition characteristics in reclaimed land. Seeds were harvested from the native common reed in Saemangeum, South Korea, the previous year and stored on an open field. The seeds were sowed in the greenhouse at the beginning of April. Common reed decomposition was studied from June to September, with the use of coarse mesh (5 mm) stem litterbags, on three samping dates and with five replicate packs per sample. These packs were dug in five soil condition (low-salinity topsoil, subsoil, high-salinity topsoil, subsoil, paddy topsoil) to 0.2 m and 0.4 m depth. The highest germination rate of common reed seeds was observed in non-salt solution, but the exhibited germination rate was 70% at 9.38 dS m-1. The plant height of young reed decreased steadily with increasing salinity, but leaf number did not decrease by 9.38 dS m-1. The survival rate of the two-year-old reed was 83.3%, which was 35% higher than that of the one-year reed. The transplant success rate was 0% in the no vinyl mulching in the soil, but the first year and second year seedlings survived rates were 63% and 83.3%, respectively, in vinyl mulching. Common reed decomposition rates were faster low salinity than high salinity. All nutrient contents were found to fluctuate significantly with time by soil conditions. We also need to study the growth rate of reed transplanting seedlings by soil moisture contents and the comparison of degradation in common reed tissues.

Paddy-upland rotation system is one of the important cropping system for improving soil quality and crop productivity. we conducted to investigate the effect of paddy-upland rotation system on soil properties and crop productivity in reclaimed tidal land. The paddy-upland rotation could be effective to conserve soil water contents and prevent from salt damage when cultivating upland crops. The first two years of maize cultivation after rice cultivation could be effective to secure stable production. However, in case of soybean crop, the rotation effect might be lower than that of maize. In the first year, the yield of soybean was 214 kg/10a. In the second and third year, the yields of soybean decreased consecutively to 152, 123 kg/10a respectively. In this paper, it would be suggested that maize be cultivated for up to two years and soybean be cultivated for one year after rice crop grown in reclaimed tidal land. This study could be provide basic data of the physico-chemical properties applicable to paddy-upland rotation system at reclaimed tidal lands.

This experiment was conducted to establish a cultivation system for sorghum in reclaimed soils. Pot experiments were used to test the effects on seedling establishment of sowing depth, soil water content, and soil salinity using seeds of Nampungchal-susu and Hwanggeumchal-susu in reclaimed soil. Field experiments were also conducted to examine differences in growth characteristics and yield production, by sowing time, and planting distance. The result of the pot experiment, examining seedling establishment at various sowing depths revealed that, it was the highest 76.7% when the seeds were sown at a depth of 3 cm. Seedling establishment did not differ with soil water content between 10~30 kpa and at 51~70 kpa. No effects of seed moisture absorption before sowing were observed. Seedling establishment showed no differences with soil salinity below 3.2 dS m-1, but decreased with Salinity above 4.8 dS m-1. In field experiments to assess the effects on seedling establishment ratio of sowing time, Nampungchal-susu was revealed to have a high seedling establishment ratio following sowing on June 15. Hwanggeumchal-susu did not exhibits effects of sowing time, on seedling establishment ratio but exhibited higher seedling establishment when in low soil salinity conditions than when sown in high soil salinity conditions. With respect to yield, the yield of the seeds sown on June 15 was higher by 13% for Nampungchal-susu and by 29% for the Hwanggeumchal-susu than that those sown on June 25. With respect to soil salinity, the yield at a soil salinity of 3.2 dS m-1 was lower by 23% than that at 1.6 dS m-1 or lower for Nampungchal-susu, and was lower by 30% Hwanggeumchal-susu. With respect to planting density, both breeds showed the highest yield at 60×10 cm. These results suggest that a sowing time of June 15 and a seeding distance of 60×10 cm are appropriate for sorghum in reclaimed land.

‘온토비’는 중, 북부 지역에서도 안정적인 월동이 가능하며 봄철 풋거름 수량이 많아 답리작 재배에 적합한 헤어리베치 품종을 육성할 목적으로 국립식량과학원에서 유전자원 ‘Ch4 (중국 도입)’에서 파생된 봄철 생육이 우세한 개체들을 선발 하여 계통육종법을 통해 개발되었다. 주요 특성은 개화기에 진한 녹엽색을 띠고, 줄기 모용 밀도가 높으며, 개화기는 전국 평균 5월 15일로써 대조품종인 ‘청풍보라’에 비해 5일 늦다. 월동율은 전국 평균 91%로써 대조품종 보다 2% 더 높은 경 향이었으며, 건물중수량은 ha당 평균 5.44톤으로써 대조품종 에 비해 17% 더 많았고, 질소함량은 ha당 평균 172 kg으로 써 대조품종에 비해 13% 더 증가하였다. ‘온토비’의 적응 지 역은 1월 최저 평균기온이 -15℃ 이상인 지역이면 전국 어느 곳에서나 재배가 가능하다(품종보호등록번호 제4748호).

This study was carried out to obtain basic information of Plasmodiophora brassicae in highland and selection of Chinese cabbage cultivars resistant to clubroot disease. According to the disease index(10% cut-off), physiological definitions of Plasmodiopho