Fish community was investigated in eutrophic Jeondae agricultural reservoir from April to November 2012. The food web structure of major fish species of Jeondae reservoir showed that due to serious organic pollution, thehyper-eutrophic condition with high chemical oxygen demand (COD), chlorophyll-a (Chl-a), total nitrogen (TN) and total phosphorus (TP), as estimated by stable isotope analysis. Total of 679 individuals were collected from the reservoir, and 9 species were identified. Interestingly, Lepomis macrochirus and Hemiculter eigenmanni known as less sensitive to pollution and water quality deterioration, dominated the reservoir, and their relative abundances were 38% and 27%, respectively. Further, the analysis of the stomach contents revealed that main food source of dominant L. macrochirus was high amount of zooplankton, which includes copepoda and cladocera, while Cyprinidae species mainly consumed organic particles with zooplankton preys. Stable isotope analysis also suggested that L. macrochirus, Carassiusauratus, Pseudorasboraparva, and H. eigenmanni are major zooplantivorous group in the Jeondae Reservoir.
본 논문에서는 온실재배 토마토에서 수분 상태를 고려한 정밀한 관개를 위하여 경직경의 변화에 근거한 자동관개 시스템을 구현하고자 하였으며 이와 같은 작물적 지표에 의한 관개제어시스템을 포트재배(closed feeding system) 조건과 포장재배 조건의 재배에 적용하여 토마토의 수량과 과실의 품질에 대하여 그 적합도를 평가하였다. 작물적 지표에 의한 관개 자동화를 위하여 경직경 측정 센서를 이용하여 측정한 경직경 일증가량(DI)를 관개 개시점의 결정에 이용하고, 동시에 이때의 관개량을 결정하기 위하여 토마토 증산모델을 적용한 마이크로 컴퓨터 자동관개 시스템을 구현하고 그 성능을 평가하였는데, 이 자동 관개 시스템을 이용하여 관개처리한 결과 포트재배에서는 토양수분에 의한 관개방식보다 수량 및 과실의 당도가 증가하였으나 포장조건에서는 관개방법간에 큰 차이가 없었다. 따라서 경직경 증가에 근거한 관개 개시점을 판단하고 관계량을 결정하는 증산모델을 사용하는 컴퓨터 시스템은 특히 closed feeding System에서 유용하며 토양조건에서는 토양의 상태, 작물의 반응 등을 고려하여 적용하여야 할 것으로 판단되었다.
The study was carried out to develop a mathematical model for evaluating the effect of organic fertilizers in organic rice production systems. A function to simulate the nitrogen mineralization process in the paddy soil has been developed and integrated into ORYZA2000 crop growth model. Inorganic nitrogen in the soil was estimated by single exponential models, given temperature and C:N ratio of organic amendments. Data collected from the two-year field experiment were used to evaluate the performance of the model. The revised version of ORYZA2000 provided reasonable estimates of key variables for nitrogen dynamics and crop growth in the organic rice production systems. Coefficient of determination between the measured value and simulated value were 0.6613, 0.8938, and 0.8092, respectively for soil inorganic nitrogen, total dry matter production, and rice yield. This means that the model could be used to quantify nitrogen supplying capacity of organic fertilizers relative to chemical fertilizer. Nitrogen dynamics and rice growth simulated by the model would be useful information to make decision for organic fertilization in organic rice production systems.
This study aimed at improving the method of oil cake application in maize. The experiment was conducted during 2 years at NAS (National Institute of Agricultural Sciences) experimental field, located in Wanju-kun, Jeollabuk-do. Growth factors and nutrient use efficiency were evaluated depending on oil cake application depth, placement, and application rate. Difference in oil cake application method and depth was tested in 2012 and different placements of oil cake application were compared in 2013. Plant height, SPAD value, and dry weight of stem and corn were investigated. SPAD value, dry weight of stem and corn were significantly higher in oil cake banding treatment (OB5, 5 cm depth) as compared to others application methods, i.e. spreading (OS0), deep banding (OB10) and banding + spreading (OB5S). In addition, dry weight of stem and corn of banding treatments (OBL, OBLL) on rhizosphere and in between row (OBR) were higher than spreading treatment (OSP). Furthermore, in case of reduced application rate in additional fertilization did not decrease dry weight of corn and increased nutrient use efficiency. Therefore, it is concluded that banding application in 5 cm-depth and rhizosphere can improve growth and nutrient use efficiency in maize production.
With increasing public concern for environmentally friendly agriculture, ecological aspect of landscape management is of growing importance. AHP (Analytical Hierarchy Process) analysis were conducted based on the delphi survey of 31 experts to evaluate the relative importance and the preference of landscape elements. Landscape components of organic farmland were classified into 2 landscape fields, 5 landscape types, 14 landscape units, and 37 landscape elements. Overall relevance score for the proposed landscape components were about 5.5 on the seven point scale. While the relative importance weight of cropland landscape field was 0.71, the weight of intra-structure landscape field was 0.29. Among the cropland landscape, relatively higher weight was assigned to farming system (0.47) and margins (0.31), as compared with hydrological system (0.22). In the farming system, crop (0.40) and farm land (0.39) were the most important landscape units. In the margins, higher weight was given to Buffer zone (0.44) and Trees (0.42). Biological habitat (0.43) ranked the highest score in the hydrological system. Preferable landscape elements were glass house, companion plants, rice paddy field, diverse crop species, small pond, and small river, which are representing ecological advantage of organic farming systems. This result indicated that the landscape elements identified in the study would be suitable to evaluate ecological aspect of rural landscape in organic farmland.
This study was conducted to evaluate the effect of organic inputs on soil properties in a newly reclaimed organic soils. The soil of the experiment site was very low in soil fertility and the physico-chemical properties were poor. Several organic input treatments with different source of nutrient were placed, including compost in combination with green manures for organic agricultural practices, chemical fertilizers for conventional agricultural practices, and control without fertilizer. The experiment was conducted with continuous cropping system during 3 years. The chemical properties concentration in compost+green manure treatment was increased continually compare to control and chemical fertilizer treatment, and closed to the recommended rate of fertilizer. The organic matter value for compost+ green manure treatment was increased from 0.86~0.96% to 2.00~2.29% by continuous nutrient supply of compost and green manure. However, further investigation on increasing of organic matter value for 3 years is necessary to monitor carefully during the long-term because it will help to clarify the all mechanisms of organic matter on organic input application way. The available phosphate value for compost+ green manure treatment was generally increased from 21.9~27.1 mg/kg to 182.0~ 394.1 mg/kg. In case of exchange cation, the concentration for compost+ green manure treatment was increased during 2 years within the range to the recommended rate of fertilizer, however, it is expected to cause a rather over supply for 3 years.
The study was conducted to investigate the effects of organic matter application on soil microbial activities and diversities in a newly reclaimed soil. Soil chemical properties, population of microbe, microbial biomass, and properties of microbial community were investigated under 4 different treatment (animal manure compost+ green manure, chemical fertilizer, and without fertilizer). The experiment was conducted for 3 years from 2012 to 2014. The most of chemical properties in the animal manure compost+green manure treatment were increased continually compare to chemical fertilizer and without fertilizer. The population of bacteria and fungi were higher in the animal manure compost+green manure treatment, however, there was no difference on actinomyces. Soil microbial biomass C content was higher in the animal manure compost+green manure treatment than in chemical fertilizer and without fertilizer. Biolog examination showed that catabolic diversities of bacterial communities were higher in the treatment of animal manure compost+green manure. It was showed that principle component analysis of the Biolog data differentiated the organic matter amended soils from NPK and control. These results indicated that application of animal manure compost+green manure had a beneficial effect on soil microbial properties.
본 시험은 유기재배 배추(Brassica oleracea L.)에서 가묘상 준비 후 잡초관리 방법이 잡초발생과 배추 생장에 미치는 영향을 조사하기 위하여 2013년 봄과 가을작기에 수행되었다. 잡초관리 방법에는 천경, 화염, PE멀칭, 무처리를 포함하였다. 천경처리는 봄작기에서 잡초억제 효과가 작았으나 화염처리는 봄과 가을작기 모두 효율적으로 잡초를 억제하였다. 봄작기에는 PE멀칭구에서 30%의 tip-burn이 관찰되었다. 가묘상 준비에 의한 잡초관리로 봄과 가을작기 모두 관행 PE멀칭과 비슷한 엽수와 신선중 및 수량이 가능하였다. 결구정도는 무처리구에서 가장 낮았다. 가을작기는 봄작기 보다 잡초생장이 감소되었고 이에 따라 배추 수량은 증가되었다. 이상의 결과로 가묘상을 통한 천경이나 화염처리는 잡초발생을 크게 감소시켜서 PE 멀칭 대용으로서 친환경적인 초생관리의 효과가 기대되었다.
To investigate the technology trends in organic farming using patent analysis, total 1,026 patents in organic farming in Australia, EU, Japan, Korea and USA between 1974 and 2014 were analyzed. The number of the patents applied in organic farming was largest in Korea, followed by Japan and the USA. Since 2000, the patent application in Korea and USA increased drastically, while in Japan the patents in organic farming were applied steadily in the late 1980s. The applied patents in organic farming were mainly dominated in the field of organic production technology (AA) especially in Korea, while those in environmental assessment were merely applied. Most patent appliers were biased to private applier (80%) than national institutes including university. With this study, it is highly recommended that national interests and R&D on the organic farming fields are needed to meet the food safety.
A survey of 31 organic farmers were conducted to investigate the actual conditions of organic matter application. The amounts of organic matter application in the fields were higher in order of fruit, vegetable and rice farm. The average was 50 ton/㏊ in vegetable farms. In the green vegetable farms saw dust and animal manure were mainly utilized to make compost. Rice straw, wood chip, and forest bushes were also used for composting. In the fruit vegetable farms materials relatively lower in nitrogen content such as rice straw and cattle manure were used in vegetative period and materials higher in nitrogen content such as oil cake and wild grass were used in reproductive phase. Nutrient balance investigated in the farm in Icheon region who produce lettuce, angelica, and kale continuously in one cropping year indicated surplus in three major nutrients. Nitrogen and phosphorous were in excess by 29 and 10 ㎏ respectively in the organic rice farm in yangpyoung region. While soil chemical properties in the organic farms are within the adequate range in open field, it is much higher than the limits in the greenhouse soils. Overall application of organic matter is in an oversupply state. This results suggested that the organic matter management should be based on the soil conditions for sustainable cultivation. Chemical composition of organic matters and soil test reports should be considered prior to the application of organic matter.
Insect pests were surveyed in 5 Rice paddy field areas of Organic paddy field and conventional paddy field. At the each rice-growth period, the occurrence rate of ‘Small brawn plant hopper was high at the case of duck raising and rice bran farming on middle stage of rice paddy field in Gang-Hwa region. The occurrence rate of Rice water weevil was high at the conventional paddy field on the early stage of rice paddy field in Yeo-Ju region. In the Hong-Seong region, the occurrence rate of ‘Rice water weevil’ and ‘Green rice leafhopper’ was high at the ‘duck raising compare to the conventional farming on the early stage of rice paddy field. According to each period, the occurrence rate of insect was high at late stage of rice paddy field, and there was no difference between each region. It showed high-occurrence tendency at duck pasture farming rice paddy field. The major natural enemies were spiders and parasites. Theridiidae and Linyphiidae were highly occurred on the conventional farming rice paddy field in Hong-Seong. Web builders containing Theridiidae, Linyphiidae and Tetragnathidae was occurred more than wandering spiders containing Lycosidae, Clubionidae and Pisauridae at various regions, and then occurrence of spiders was different at the various regions but was not different at each farming system.
Diseases were surveyed in 5 Rice paddy field areas of Organic paddy field and conventional paddy field. The 3 major diseases, rice leaf blast, bacterial leaf blight and sheath blight in rice were surveyed at duck raising, rice bran and conventional rice paddy field. They were serious in duck raising paddy field, rice bran paddy field more than conventional paddy field. The Ilpum variety were infected seriously more than Chucheong. At the effectivity test of the environment-friendly substance for the rice-seed sterilization, 1000-times diluted brown-rice vinegar showed controlling effect against Bakanae disease, and germination rate also was good. There was no Weeds Control efficacy by cultivating of hairy vetch in rice paddy field. However, extract of hairy vetch Leaf and root repressed the germinating of lettuce seed.
농산물의 고품질 유지 저온저장 및 저장물 관리의 편리화를 위해서 원거리에서 저장고 환경을 감시할 수 있는 인터넷을 이용한 저온저장고 환경감시 및 경보 시스템을 개발하였으며, 그 내용을 요약하면 다음과 같다. 실용화를 촉진하기 위하여 환경감시 및 경보 시스템의 저온저장고측 컴퓨터를 산업용 제어반인 PLC(Programmable Logic Controller)로 하여 원거리 환경감시 및 경보시스템을 제작하였다. 농가에서 사용하기 쉽게 윈도우용 환경하