Rice (Oryza sativa) is the most important staple food of over half the world’s population. This study was conducted to evaluate the possible impact of transgenic rice cultivation on the soil microbial community. Microorganisms were isolated from the rhizosphere of GM and non-GM rice cultivation soils. Microbial community was identified based on the culture-dependent and molecular biology methods. The total numbers of bacteria, fungi, and actinomycete in the rhizosphere soils cultivated with GM and non-GM rice were similar to each other, and there was no significant difference between GM and non-GM rice. Dominant bacterial phyla in the rhizosphere soils cultivated with GM and non-GM rice were Actinobacteria, Firmicutes, and Proteobacteria. The microbial communities in GM and non-GM rice cultivated soils were characterized using the denaturing gradient gel electrophoresis (DGGE). The DGGE profiles showed similar patterns, but didn’t show significant difference to each other. DNAs were isolated from soils cultivating GM and non-GM rice and analyzed for persistence of inserted gene in the soil by using PCR. The PCR analysis revealed that there were no amplified protox gene in soil DNA. These data suggest that transgenic rice does not have a significant impact on soil microbial communities, although continued research may be necessary.

The cultivation of genetically modified (GM) crops has increased due to their economic and agronomic advantages. Before commercialization of GM crops, however, we must assess the potential risks of GM crops on human health and environment. The aim of this study was to investigate the possible impact of Bt rice on the soil microbial community. Microbial communities were isolated from the rhizosphere soil cultivated with Bt rice and Nakdong, parental cultivar and were subjected to be analyzed using both culture-dependent and molecular methods. The total counts of bacteria, fungi, and actinomycetes in the rhizosphere of transgenic and conventional rice were not significantly different. Denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA genes revealed that the bacterial community structures during cultural periods were very similar each other. Analysis of dominant isolates in the rhizosphere cultivated with Bt and Nakdong rice showed that the dominant isolates from the soil of Bt rice and Nakdong belonged to the Proteobacteria, Cloroflexi, Actinobacteria, Firmicutes, and Acidobacteria. These results indicate that the Bt rice has no significant impact on the soil microbial communities during cultivation period. Further study remains to be investigated whether the residue of Bt rice effect on the soil environment.

Soybean self-sufficiency in Korea was 22.5% in year 2011, and as free trade agreement between Korea and US comes into effect, the amount of soybean importation increases. In 2012, paddy field soybean cultivation was over 0.1 million ha and it is expected to increase continuously due to rise in market price of soybean. Moreover, double cropping system including paddy field soybean is widely adopted nationwide, but studies on appropriate cultivar for this environment are insufficient. In this research, the effect of planting date and different cultivars on soybean growth and yield was investigated for three planting dates (June 20, July 5, and July 20) with 15 cultivars. According to ANOVA test, soybean yield was significantly different depending on sowing date and cultivars and interaction between sowing date and cultivars was also detected, meaning each of cultivars resulted different yield depending on sowing date. When planted on July 20, stem length, nod number, branch number and grain weight was decreased because of short growing period, resulting in yield decrease. Percentage of yield obtained from July 20 in contrast to that of June 20 showed that Pungwon, Nampung and Daepung recorded the least yield decrease and the highest yield when planted late. Evaluation of late-sowing-adaptable soybean cultivar in paddy field is now being carried on following last year.

This study was carried out to select optimal shade materials among four-layered polyethylene (PE) net (FLPN), aluminium-coated PE sheet (APSS), and blue PE sheet (BPSS) in condition of paddy field cultivated 6-year-old ginseng. The order of light-penetrated ratio and air temperature by shade materials was BPSS 〉 APSS 〉 FLPN. Light-penetrated ratio of BPSS before two fold shade was more 3 times and 2 times than that of FLPN and APSS, respectively. Air temperature of BPSS was also higher 1.6℃ and 1.4℃ than that of FLPN and APSS, respectively. BPSS showed good cultural environment because all of light-penetrated ratio and air temperature were become higher in spring and fall season but lower in summer season by additional shade with two-layered PE net. Survived-leaf ratio was highest in BPSS and lowest in FLPN causing a little water leak on a rainy day. Rusty-root ratio was also highest in FLPN because soil moisture content was increased by water leak. The order of root yield was BPSS 〉 APSS 〉 FLPN, and the cause of highest yield in BPSS was higher light-penetrated ratio during spring and fall season, higher survived-leaf ratio, and lower rusty-root ratio than that of APSS and FLPN. BPSS showed highest total ginsenoside content because of high light-penetrated ratio, blue light effect, and the difference in dry matter partitioning ratio such as low taproot ratio, and high lateral root ratio.

본 연구는 중금속으로 오염된 논토양에서 비소 흡수능이 우수한 봉의꼬리(Pteris multifuda)를 재배할 때 차광처리가 봉의꼬리의 생육과 토양 내 비소 흡수에 미치는 영향을 분석하기 위하여 수행하였다. 비소로 오염된 (구)장항제련소 인근의 논토양에서 수행하였으며, 각 실험구의 크기를 2×2m로 조성하였고, 동일한 생육단계의 봉의꼬리를 20×20cm 간격으로 식재하여 24주간 재배하였다. 차광조건에 따른 봉의꼬리의 생육을 조사하였고, 식물체 내 비소 축적량 및 토양의 비소 변화량은 ICP를 이용하여 분석하였다. 연구의 결과, 중금속으로 오염된 논토양에서 차광에 의한 봉의꼬리의 생육은 무차광에 비해 차광 처리구에서 왕성하였다. 봉의꼬리 지상부의 비소 축적량은 차광(140.9mg·kg-1)에 비해 무차광 처리구(169.8mg·kg-1)에서 다소 높았으며, 지하부의 비소 축적량은 비슷한 경향을 보였다. 그러나 생육은 70% 차광 처리구에서 월등히 우수하여, 토양에서 흡수한 비소의 함량은 차광처리구에서 오히려 더 많았다. 봉의꼬리의 비소 이동계수(TR)는 차광처리에 관계없이 0.87~0.89로 매우 높아 흡수한 비소를 지상부로 빠르게 이동시키므로 생육 후 지상부의 제거처리에 의해 토양 내의 비소를 효과적으로 제거할 수 있으리라 생각된다.

밭전환 1년차 논의 토양물리성 악화를 개선하고 사료용 옥수수 생육을 증진시키기 위한 심토파쇄의 효과를 살펴본 결과 다음과 같은 결과를 얻었다. 1. 심토파쇄에 의해 토심 25~35 cm 층위의 토양의 경도가 크게 감소하였고 토층 15~30 cm에서 가밀도, 공극율 및 고상비율 등 하층토의 토양물리성이 개선되는 것으로 나타났다. 2. 심토파쇄 추가 시 옥수수의 간엽 및 이삭의 생육이 크게 증가하였으며, 특히 이삭당 립수의 증가가 이삭중을 크게 증가시키는 것으로 나타났다. 3. 심토파쇄 추가 시 옥수수는 이삭 및 간엽의 수량증가에 의해 TDN 수량이 19~39% 증가하였으며, 특히 습해에 의해 생육이 불량한 2011년도의 옥수수의 생육촉진 효과가 컸다.

벼 수확동시 보리조파 전 적정 낙수시기는 배수가 불량한 전북통인 미사질양토에서 1. 토양수분이 많을수록 입모율이 감소하였다. 2. 토양수분이 많을 경우 콤바인 작업시 궤도의 침하로 작업시간이 길어졌으며, 수분함량이 적을 경우에는 작구부에 부하가 가중되어(경도증가) 작업시간이 길어지는 것으로 나타났다. 3. 낙수시기에 따른 보리생육 및 수량 등은 차이가 없었으나 수수는 낙수시기가 늦을수록 적었다. 4. 벼 수량과 천립중은 통계적인 차이는 인정되지 않았으나, 낙수시기별 현미 천립중이 21.7~22.2 g 범위로 낙수가 빠를수록 가벼워지는 경향을 나타내었다. 5. 이상의 결과에서 배수가 불량한 미사질양토에서는 토양경도와 작업시간을 감안한 적정 토양수분 함량은 33% 정도로 입모율 확보 및 수량증대에 좋을 것으로 판단되었다.

This study aims to find out the geographical distribution, the physical structure and characteristic of Gudle-jang Paddy-field in Cheongsando. On the basis of this study, the potential value and the assignment for the preservation of Gudle-jang Paddy-field were suggested. Gudle-jang Paddy-field is centrally distributed to Cheongsando and has various features as follows. First, it has the Ondol structure which is used Gudle-jang. Second, it has an irrigation canal which has functions of the tank and the prevention of cold-weather damage as well as the irrigation and drainage canal. The values of Gudle-jang Paddy-field are as follows; 1) It is the peculiar and inherent agricultural structure which is only found in Cheongsando. 2) It is the structure that the agricultural civil engineering and the agricultural water management technique of traditional methode are applied. 3) It has the worths of the traditional culture of Korea. 4) It is the important resource creating superb rural landscape of the region. In spite of these values of Gudle-jang Paddy-field, there were little efforts to preserve it. From now on, it is needed to form of sympathy about the value of Gudle-jang Paddy-field and to make efforts for preservation of it. Also the institutional and political strategy should be provided to preserve and manage Gudle-jang Paddy-field.

To develop the practical cultivation for paddy field, we investigated the properties of paddy soil, growth characteristics and ginsenoside content of 6-year-old ginseng, Cheonpung variety between poor drainage class (PDC) and imperfect drainage class (IDC). Groundwater level in PDC showed monthly small changes of 20~30 cm, while IDC showed monthly great changes of 28~71 cm depending on rainfall. Soil moisture content in PDC and IDC was 17.2%, 22.5%, respectively. Air temperature in IDC was lower than 0.3℃, while soil temperature was higher than 0.8℃ compare to PDC, respectively. Main soil color of PDC was grayish olive, while IDC was brownish olive. PDC showed yellowish mottles only at underground of 20~40 cm, while IDC showed that at underground of 30~90 cm. IDC showed lower pH, EC, potassium, calcium and magnesium content, but higher organic matter, phosphate, and iron content than that of PDC, respectively. All of EC, organic matter, potassium, calcium, and magnesium content were decreased, but iron content was increased at the subsoil layers of PDC. All of EC, organic matter, phosphorus, and potassium content were decreased, but calcium and magnesium content were increased at the subsoil layers of IDC. Root yield in IDC was more increased by 33% than that of PDC. The moisture content and rusty ratio of ginseng root in IDC were lower than that of PDC. Ginsenoside content in IDC was higher than that of PDC because the ratio of lateral and fine root showing relatively high content of ginsenoside was higher in IDC than that of PDC.

본 연구는 신간척지에서 벼 기계이앙재배시 염 피해가 적으면서 안정적인 쌀수량 확보를 위하여 모 종류를 어린모, 치묘, 중묘, 폿트묘로 새로 조성된 간척지인 새만금 계화포장에 이앙하여 수행한 내용을 요약하면 다음과 같다. 1. 2년 평균 토양염농도는 이앙전 0.16%에서 환수후 이앙 직후에는 0.04%로 낮아졌다. 2. 모 종류별 출수기는 폿트묘 이앙이 8월 14일인데 비해중묘이앙은 2일, 치묘이앙은 3일, 어린모이앙은 5일 늦게 출수되었다. 3. 도복관련형질에서 중묘이앙이 도복지수가 가장 높아 포장도복 역시 중묘이앙이 반도복 정도 되었다. 4. 수량구성요소를 보면 이앙모 종류별 등숙비율과 현미천립중은 비슷하였고, 주당수수는 치묘>어린모>폿트묘>중묘이앙 순으로 많았으며, 쌀수량은 어린모=치묘>폿트묘>중묘이앙 순으로 많았다. 5. 이앙모 종류별 쌀 품질에서 완전립비율은 치묘>중묘=어린모>폿트묘 순으로 높았고, 아밀로스함량과 단백질 함량은 이앙모 종류간 차이가 없었다. 결론적으로 새로 조성된 간척지에서 벼를 기계이앙재배할 때 안정적인 쌀 수량 확보를 위한 적정 이앙모는 어린모와 치묘가 적합하다고 판단된다.

When ginseng seedlings are cultured in paddy fields, quality degradation and yield reduction are induced by severe plant loss with chlorosis on leaves occurred physiological disorder by excessive salt and poor drainage, rusty-root occurrence, and root rot etc. Accordingly, in order to solve these problems, this study was performed to investigate the treatment method, concentrations and time of activated ion calcium as environment-friendly agricultural materials. Activated ion calcium is an enriched and purified water-soluble mineral calcium component for absorbing quickly into plant as a highly functional calcium and it is an alkaline calcium of 37% (370 ml/1 l) concentration with pH 13. Treatment method was that ginseng seeds were sown after removing water in the shade after seed immersion for 1 minute with active ion calcium of 20-fold diluted solution, and then irrigated 4l per 3.3 m2 with 200-fold, 400-fold, and 600-fold diluted solution before emergence on late March, and supplied 1 time on leaves with 500-fold diluted solution in June and July respectively. The disease rate by treatment of activated ion calcium was that on the treatment of soil irrigated with 200-fold diluted solution compared to non-treated soil, damping-off was 33%, anthracnose was 100% reduced and the occurrence rate of rusty-root was 30% reduced. In addition, when active ion calcium of 200-fold diluted solution were soil irrigated, first and second grade ginseng were respectively 26% and 22% produced more, compared with control.

Soil NH4-N content became higher in proporlion to the increase in the urea application rate, while in livestock faeces compost (LFC) plots, it became lower than in urea plots and had no significant difference statistically among LFC plots. There was a close relationship between phosphate ferlilization rate and the increment of soil available phosphate content after experiment resulting y=O. 1788x-6. 169 (R~=O. 9425) when applied fused superphosphate ferlilizer, and y=0.0662x-2.689(R~=0.9315) when applied LFCs by the same amounts of phosphate (x: phosphate application, kg ha, y: increment in soil available phosphate content, mg kg). Plant height, number of stems, nutrients uptake by rice and rice yield showed higher levels in N 100, 150% application plots of chemical ferlilizers, while every LFC plots exhibited lower values and no significant difference among them. Relative nitrogen ferlilization efficiencies of LFCs compared to urea was 12.3% for cattle faeces compost (CaFC), 8.8 for swine faeces compost (SwFC) and 24.6 for chicken faeces compost (ChFC), respectively.

Green manure crops play an inportant role in organic farming. Field experiment was conducted at paddy soi1 (fine loamy, mixed, nonacid, mesic family of Aeric Fluvaquentíc Endoquepts) ín 2008/2009 to 2009/2010 at the Natíonallnstítute of Crop Science (NICS), RDA, Suwon, Gyeonggí provínce, Korea. This expe꺼ment was carried out to evaluate the biomass of haíry vetch (Vicia víllosa) and growth of rice (Oryza satíva) by cjífferent seedíng rates. Seeding rates of hairy vetch consisted of 30, 60, and 90 kg ha-' by broadcasting before rice harvesting. The biomass af)d nitrogen production of hairy vetch were not significantly different between 60 kg ha-’ and 90 kg ha-’ of seeding rates. Also, rice yield was not siginicantly differnt between seeding rate 60 kg ha-’ of hairy vetch and conventional pratice for two years. Therefore, we suggested that seeding rate of hairy vetch should be reduced by continuous cropping and incoportion of hairy vetch under rice-based cropping system.

Nitrogen fíxatíon by legumes can be valuable sources for organíc farmíng. Thís study was to ínvestígate the effect of dífferent legume mixtures on nitrogen fíxatíon and transfer to grasses on sp끼ng paddy fíeld. Three different mixtures were used (rye+haíry vetch, Italían ryegrass+crímson clover, oat+pea) in a randomized complete block design with three replications and sowed ín pots wíth different sowing rate (5:5 rye:haíry vetch,7:3=ltalian:crimson, 6:4=oat:pea) on early March. t 5NH4hS04 solutíon at. 99.8 atom%15N was applied to the each pot at the rate of 2kg N ha.1 on 16h Ap끼1. Forage were harvested at ground level ín heading stage and separated ínto legume and grass. Total N content and 15N value were determíned using a continuous f10w stable ísotope ratio mass spectrometry. DM yield of rye+vetch, Italian+crimson and 。at+pea were 6,607, 3,213 and 4,312kg/ha, respectively. Proportion of N from fixatíon was 0.73(rye+vetch), 0.42(1talian+crimson) and 0.93(oat+pea). The percentages of N transfer from legume to grass were from 61% to 24% in dífferent method by treatments and -35% to 21% in ísotope dilutíon method.

Supplying rate of nitrogen at HV was 172.8 kg ha-1, HV/B was 64.3 kg ha-1 and B was 38.6 kg ha-1. The Rice yield was 7.05 ton ha- I when the nitrogen supply was the largest with HV and 5.42 ton ha- I was produced on HV/B. The chemical characteristics of soil have lower pH and exchangeable cations(Ca and Mg) at B, HV and HV/B, rather than at CF because green manure was applied at the former step. However, the physical characteristics of the soil and the porosity showed different tendency which was that it was better at the green manure crops than CF. Nitrogen nutrient balance was showed the most balanced at CF and field of application of green manure crops were required the appropriate management if future crops would be cultivated because nitrogen nutrient could be exhausted or accumulated. Introduction

In order to evaluation of beneficial functions for organic farming, we have divided beneficial functions as 9 sub-functions such as flooding control, fostering water resources, purifying the air, mitigating summer climate, purifying water quality, decreasing soil erosion, accumulating soil carbon, conserving biodiversity, and preventing accidents from pesticides. And they were quantified by searching related repots and statistics, and surveying fields. Organic farming, especially organic paddy farming, showed that some functions like fostering water resources, accumulating soil carbon, conserving biodiversity, and preventing accidents from pesticides were higher than conventional paddy farming, while the others were almost similaι The foste꺼ng water resources function was evaluated as 4,297 ton ha-1 year-1 to increase about 3.6% comparing with that of conventional farming. New function for accumulating soil carbon at organic paddy fields has been assessed by 4.67 ton ha-1 in terms of long periods over 10 years. Considering area of organic paddy farming in Korea and value of carbon price， it was evaluated monetary value as 22.4 to 84.1 billion won using replaced method. It could be also evaluated that flooding control, fostering water resources, purifying the air, mitigating summer climate, purifying water quality, decreasing soil erosion, and preventing accidents from pesticides were 2,980, 123.4, 482.6, 87.5, 0.9, 55.6, and 284.1 billion won, respectively. Conserving biodiversity function would be very big at organic farming though it couldn ’l be evaluated as monetary value.

For this research, they were monitored CO2 flux and environmental factors (CO2 concentration, soil temperature, soil moisture, soil organic carbon, soil pH, soil Eh) in foreshore, paddy field and woods sites at the winter season (January 2009) and the summer season (September 2009). Seasonal and spatial variations for monitored data were analyzed, and linear regression functions of CO2 flux as environmental factors were estimated. CO2 fluxes averaged between surface and atmosphere monitored in foreshore and paddy field at the winter season were shown -8 mgCO2m-2hr-1 and -25 mgCO2m-2hr-1, respectively. CO2 fluxes averaged between surface and atmosphere monitored in foreshore and paddy field at the summer season were shown 47 mgCO2m-2hr-1 and 117 mgCO2m-2hr-1, respectively. Thus, CO2 was sunk from atmosphere to surface at the winter season and it was emitted from surface to atmosphere at the summer season. CO2 fluxes in woods site were emitted 145 mgCO2m-2hr-1 at the winter season and 279 mgCO2m-2hr-1 at the summer season.

This study was conducted to examine major growth responses, the production and partitioning of dry matter on different growth stages, and yields and to select the optimal shading material in both quality and productivity of ginseng. Two cultivars of ginseng, Cheonpoong and Geumpoong, were cultivated in the paddy soil with three different shading materials; three-layered blue and one-layered black polyethylene (TBP), blue polyethylene sheet (BPS), and aluminium-coated polyethylene sheet (APS). Plant heights were linearly increased until June 24 and then maintained with showing higher height in Cheonpoong than that in Geumpoong cultivar. Root lengths were gradually increased until October 16. They were longer in Cheonpoong than that in Geumpoong cultivar, showing slightly longer with APS compared to TBP and BPS. The ability of producing dry matter of leaves was much higher from April to June compared to those of other growth periods, whereas its ability of root was concentrated from the end of June to the end of August. Among the shading materials, the ability of producing dry matter of shoot was higher with TBP than those with BPS and APS, while its ability of root was not appeared certain tendency unlike the shoot. The yield of ginseng roots was the highest with TBP among three shading materials and it was higher in Cheonpoong than that of Geumpoong cultivar. The shading materials which affect the light intensity and the temperature would be considered as an important factor to get better quality and productivity of Korean ginseng.