To study the faunal compositiion of spiders as natural enemies of the insect pests and their seasonal fluctuation in paddy fields of Taegu, the survey was carried out 12 times between June and September. 1971. 1. The spiders collected in paddy field of Taegu during the survey period were 45 species of 30 genera of 10 families. 2. In percentage composition the spiders of the genus Pirata were most abundant. Among the other genera, the species of the genus Neoscona, Lycosa, and Marpisa were more abundant in the above-written order. 3. Pirata subpiraticus, Neoscona doenitzi, Lycosa sp., Pardosa T-insignita and Marpisa magister were the 5 major species of abundant spiders. 4. Comparing the spider-fauna of the paddy field of Korea with that of Japan, Taiwan and Thailand, 2 species of 2 genera of the family Gnaphosidae were found in Korea only The abundant and common species It·ere deeply different each other. 5. Pirata subpiraticus, Lycosa sp. and Pardosa T-insignita appeared abundantly between June and July while Neoscona doenitzi and Marpisa magister were few in these periods. But no Pirata subpiraticus, Lycosa sp. and Pardosa T-insignita appeared in August while Neoscona doenitzi and Marpisa magister were abundant in this period. Then, in September as between June and July, Pirata subpiraticus, Lycosa sp. and Pardosa Tinsignita were abundant while Neoscona doenitzi and Marpisa magister decreased.

Cyanobacteria have been used as pollution indicator species in freshwater ecosystems, and identifying their fluctuations can be an important part about management of surface waters globally. Cyanotoxins produced by cyanobacteria are directly or indirectly a threat to human and environmental health. In order to confirm the potential risk of these cyanotoxins, the fluctuations of phytoplankton and phylogenetic analysis of cyanotoxin synthetase genes were conducted at each point in the Yeongsan River water system in Gwangju from November 2021 to October 2022. Diatoms which grow well in winter were dominant at 99.4 ~ 99.5%, and diatoms and green algae were dominant from the spring to autumn when the water temperature rises. Stephanodiscus spp. were dominant at 92.7 to 97.5 % at all sites in the winter, and Aulacoseira spp., which grow in warm water temperatures, were dominant in summer and autumn. Microcystis aeruginosa was dominant at 25.2% in summer only at site 5. mcyB and anaC have been detected as cyanotoxin synthetase genes. The phylogenetic tree of anaC could be divided into two groups (Group 1 & Group 2). Group 1 contained Aphanizomenon sp. and Cuspidothrix issatschenkoi. It is combined with Aphanizomenon sp. and Cuspidothrix issatschenkoi, which are known to produce cyanotoxins.

In this study, the hydraulic gradient was calculated using the groundwater level and rainfall observed in the Hyogyo-ri area for a year, and the change in the hydraulic gradient according to the rainfall was analyzed. It was found that the groundwater level increased as the rainfall increased in all groundwater wells in the research site, and the groundwater level rise decreased as the altitude of the groundwater well increased. The hydraulic gradient in the research site ranged from 0.016 to 0.048, decreasing during rainfall and increasing after the end of the rainfall. As the rainfall increased, the groundwater level rise in the low-altitude area was more than the high-altitude area, and the hydraulic gradient decreased due to the difference in groundwater level rise according to the altitude. Through this study, it was found that the influence of rainfall is dominant for the fluctuation of the hydraulic gradient in the unconfined aquifer.

In this study, we analyzed seasonal variations in carbon dioxide fluxes, concentrations, and soil temperatures over three years in unvegetated tidal flats in the Beolgyo area. We also investigated the correlations between carbon dioxide fluxes and influencing factors. The average carbon dioxide flux was positive in summer and autumn but negative in winter and spring. A positive correlation was observed between carbon dioxide flux and soil temperature in spring whereas a negative correlation was noted in summer. In summer and autumn, as the soil temperature increased, the carbon dioxide flux decreased. In contrast, in spring and winter, as the soil temperature decreased, the carbon dioxide flux increased. Overall, this study reveals the significant influence of soil temperatures on carbon dioxide fluxes between the surface layer of the tidal flat and atmosphere.

The study attempts to analyze the impact of firm’s risk on capital structure in the context of seasonal and non-seasonal businesses. We use two independent variables namely credit risk and systematic risk and one dependent variable to explore this connection. Sugar sector is taken as seasonal while the textile sector as non-seasonal businesses. The panel data of twenty-five firms from each sector are taken ranging for the period of 2012 to 2019 which has been retrieved from their annual reports for empirical analysis of the study. The results reveal the negative impact of credit risk on capital structure in both types of businesses. Increasing (decreasing) one point of credit risk causes a decrease (increase) leverage ratio by 0.27 points for seasonal while increasing (decreasing) one point of credit risk causes to decrease (increase) leverage by 0.15 points for non-seasonal businesses. Furthermore, the study shows positive impact of systematic risk on leverage ratio in non-seasonal business and no impact in seasonal business. Any increase (decrease) in the systematic risk causes an incline (decline) leverage ratio by 2.68 units for non-seasonal businesses. The study provides a guideline to managers for risk management in businesses. The research focusses on theoretical as well as managerial and policy implications on risk management in businesses.

Muons and neutrons are representative secondary particles that are generated by interactions between primary cosmic ray particles (mostly protons) and the nuclei of atmospheric gas compounds. Previous studies reported that muons experience seasonal variations because of the meteorological effects of temperature. The intensity of neutrons has a typical modulation with various periods and reasons, such as diurnal and solar variation or transient events. This paper reports that cosmic ray particles, which were observed by neutron monitors, have seasonal variations using the daily data at the Oulu neutron monitor. To eliminate the effects of solar activity across time, the daily data were normalized by two different transformations: transformations with respect to the grand mean and yearly mean. The data after transformation with respect to the yearly mean showed more statistical stability and clear seasonal variations. On the other hand, it is difficult to determine if the seasonal variation results from terrestrial effects, such as meteorological factors, or extraterrestrial effects, such as the position of the Earth in its orbit of revolution.

This study was conducted to analyze seasonal variations of de-icing salt ions harvested from soils and plants according to salt damage of Pinus densiflora f. multicaulis, a evergreen conifer, on roadsides. Pinus densiflora f. multicaulis was divided into three groups referred to SD, ND, and WD (serious salt damage (SD) = 71 100%, normal salt damage (ND) = 31 70%, and weak salt damage (WD) = 0 30%) based on the degree of visible foliage damage, and measured acidity (pH), electrical conductivity(EC), and de-icing salt ions (K+, Ca2+, Na+, and Mg2+) harvested from soils and plants. The results indicated that acidity, electrical conductivity, and de-icing salt ions of soils and plants were significantly affected by seasonal variation and salt damage. In addition, a strong positive liner relationship was observed in plants between the concentration of de-icing salts and salt damage in spring, while the relationship among seasonal variation and salt damage in soil were not significant. The results from this study has important implications for the management of conifer species in relation to salinity and roadsides maintenance.

Seasonal changes in the CO2 fixation rate and water-use efficiency in the leaves of six evergreen and two deciduous broad-leaved tree species on Jeju Island, Korea, were measured using a portable photosynthesis analyzer, to identify which species are most efficient in taking up CO2 from the air. The CO2 fixation rate was high in the deciduous species in spring and summer and decreased in fall, whereas it was high in the evergreen species in summer and fall and decreased in winter. The rate remained high in the deciduous tree Prunus yedoensis from spring to fall (> 7.1 μmol CO2/m2/s) and in two evergreen trees, Castanopsis cuspidata var. sieboldii and Cinnamomum camphora, in summer and fall (7.0 9.9 μmol CO2/m2/s). Therefore, these tree species fix atmospheric CO2 effectively. The water-use efficiency was higher in evergreen species than in deciduous species regardless of the season. Exceptionally, it was high in the deciduous species Zelkova serrata in spring and summer (> 100 μmol CO2/mol H2O), suggesting that Z. serrata is a useful tree for dry conditions due to its tolerance of water stress. The regressions of the CO2 fixation rate versus the evaporation rate and stomatal conductance were linear and non-linear, respectively. This suggests that the stomatal activity of leaves plays an important part in CO2 fixation of plants. In conclusion, C. cuspidata var. sieboldii, C. camphora, and P. yedoensis should be planted along roads or in urban spaces for the greening of cities and mitigation of CO2 concentrations in the air.

We have investigated the variations of sporadic E (Es) layer using the measurements of digisondes at Icheon (37.14°N, 127.54°E, IC) and Jeju (33.4°N, 126.30°E, JJ) in 2011–2018. The Es occurrence rate and its critical frequency (foEs) have peak values in summer at both IC and JJ in consistent with their known seasonal variations at mid-latitudes. The virtual height of the Es layer (h’Es) during equinox months is greater than that in other months. It may be related to the similar variation of meteor peak heights. The h’Es shows the semidiurnal variations with two peaks at early in the morning and late in the afternoon during equinoxes and summer. However, the semi-diurnal variation is not obvious in winter. The semi-diurnal variation is generally thought to be caused by the semi-diurnal tidal variation in the neutral wind shear, whose measurements, however, are rare and not available in the region of interest. To investigate the formation mechanism of Es, we have derived the vertical ion drift velocity using the Horizontal Wind Model (HWM) 14, International Geomagnetic Reference Field, and Naval Research Laboratory Mass Spectrometer and Incoherent Scatter Radar-00 models. Our results show that h’Es preferentially occur at the altitudes where the direction of the vertical ion velocity changes. This result indicates the significant role of ion convergence in the creation of Es.

The study was initiated to compare seasonal nutrient variations and rice (Oryza sativa L.) productivity in each of leading rice farm with conventionally managed and recommended fertilized of the large-scale environment-friendly agricultural districts in Jangheung, Suncheon, and Okcheon provinces in 2017. Suncheon rice experimental farm plots included a recommended fertilization plot that had been additionally sown hairy vetch in the fall of previous year, while Okcheon rice farm included a recommended fertilization plot applying half amount of the compost in the conventional plot. A Jangheung rice farm only practiced crop-livestock farming system. Soil pH and EC in all experimental plots were suitable levels for rice growth to cultivate. Seasonal soil pH from March to September was the highest for Suncheon rice farm, and seasonal soil EC was the highest for Jangheung rice farm. Seasonal soil T-N increased in all the plots from March to June in particular for Suncheon rice farm, and Jangheung rice farm had the lowest seasonal soil P. Seasonal soil K decreased in all the plots, with the lowest levels observed for Okcheon farm. Seasonal soil NH4 + mostly increased by up to 90 mg/kg in Jangheung rice farm from March to June. Seasonal plant T-N, P and K concentrations were the highest for Jangheung rice farm. Seasonal plant T-N and P concentrations decreased from June to September, but K leveles were fluctuated between 2.0% and 2.5%. Seasonal SPAD value was the lowest in Suncheon conventional plot. Jangheung rice farm plot produced 6,303 kg of rice per ha, which was approximately two times higher than those of Okcheon recommended plot. The seasonal T-N, P and K balance was the highest in Okcheon conventional plot, with the lowest values observed for Suncheon conventional plot. As a result, Suncheon recommended plot showed relatively low levels of seasonal macro-nutrient balance and the highest rice production, which could be the most environmentally friendly farm practiced conducted in this study.

This study was initiated to find possibility of substitute of gibberellin acid and to prevent negative girdling effect such as slow growth of ‘Niitaka’ (Pyrus pyrifolia Nakai) trees, a major pear cultivar, at harvest and at 60-, 90-, and 120-d after storage. Seasonal wiring with 3.0-mm-diameter were applied on the main branch at 70, 80, 90, 110, and 130 days after full bloom (DAF) to compare the fruit quality and storability. Fruit weight and sugar contents were the greatly increased by the wiring treatment at 110 DAF, with the lowest values observed for the wiring at 70 DAF. All the wiring treatments reduced fruit acidity but did not affect fruit firmness. a-value on fruit skin was the highest for wiring at 110 DAF and 130 DAF, advancing fruit ripening. The lowest fruit weight loss was occurred at wiring at 110 DAF. a-value on fruit skin was the highest for wiring at 90 DAF and 110 DAF. Wiring at 80 DAF the most increased floral bud diameter, resulting in the lowest L:D ratio of 1.74 observed. As for the mineral nutrients concentrations of floral buds, the concentration of K (0.63%) and Mg (0.31%) were the highest after 80 DAF wiring treatment, whereas Ca and P concentrations did not differ among treatment plots. The leaf K concentrations was the highest in the 130-day wiring treatment (0.76%) and in the control plot (0.78%), whereas there was no significant difference in the concentrations of either Ca or P among treatment plots. Short periods of wiring increased foliar Mg concentrations. In floral buds, carbohy-drates showed a tendency for accumulating at a lower concentrations (7.75%) after 70 DAF wiring treatment, which was a relatively short treatment period. On the other hand, the carbohydrate concentrations in leaves showed a tendency for accumulating at lower concentrations after 130 DAF wiring treatment (2.51%), which is a long treatment period, and in the control plot (2.43%). Wiring increased the size and sugar content of fruits, and influenced fruit storability. For the wiring treatment period was delayed, the carbohydrate concentration in flower buds showed curvilinear correlation and the negative correlation with the carbohydrate in leaf tissue.

Unit load factor, which is used for the quantification of non-point pollution in watersheds, has the limitation that it does not reflect spatial characteristics of soil, topography and temporal change due to the interannual or seasonal variability of precipitation. Therefore, we developed the method to estimate a watershed-scale non-point pollutant load using seasonal forecast data that forecast changes of precipitation up to 6 months from present time for watershed-scale water quality management. To establish a preemptive countermeasure against non-point pollution sources, it is possible to consider the unstructured management plan which is possible over several months timescale. Notably, it is possible to apply various management methods such as control of sowing and irrigation timing, control of irrigation through water management, and control of fertilizer through fertilization management. In this study, APEX-Paddy model, which can consider the farming method in field scale, was applied to evaluate the applicability of seasonal forecast data. It was confirmed that the rainfall amount during the growing season is an essential factor in the non-point pollution pollutant load. The APEX-Paddy model for quantifying non-point pollution according to various farming methods in paddy fields simulated similarly the annual variation tendency of TN and TP pollutant loads in rice paddies but showed a tendency to underestimate load quantitatively.

To establish initial response scenarios for nuclear accidents around the Kori nuclear power plants, the potential for radionuclide diffusion was estimated using numerical experiments and statistical techniques. This study used the numerical model WRF (Weather Research and Forecasting) and FLEXPART (Flexible Particle dispersion model) to calculate the three-dimensional wind field and radionuclide dispersion, respectively. The wind patterns observed at Gijang, near the plants, and at meteorological sites in Busan, were reproduced and applied to estimates of seasonally averaged wind fields. The distribution of emitted radionuclides are strongly associated with characteristics of topography and synoptic wind patterns over nuclear power plants. Since the terrain around the power plants is complex, estimates of radionuclide distribution often produce unexpected results when wind data from different sites are used in statistical calculations. It is highly probable that in the summer and autumn, radionuclides move south-west, towards the downtown metropolitan area. This study has clear limitations in that it uses the seasonal wind field rather than the daily wind field.

The interannual variability of summer temperature during June-August (JJA) in South Korea was associated with geopotential height averaged in the East Sea (Korea-Japan Index, KJI) and in the subtropical western North Pacific (Western North Pacific Subtropical High Index, WNPSHI). The KJI was coupled with a decaying El Niño one month in advance, while the WNPSHI was influenced by Sea Surface Temperature (SST) anomaly in the western North Pacific and a developing El Niño one to three months ahead. Additionally, the JJA temperature over South Korea was affected by SST anomaly in the western North Pacific in May. Based on these teleconnections, a multivariate regression model using the SST surrogates for the KJI and WNPSHI and an univariate model using an area-averaged May SST were developed to reconstruct the JJA temperature over South Korea. Both of the empirical models reproduced the JJA and monthly temperatures reasonably well. However, when the simulated SSTs from global climate models were used, the multivariate model outperformed the univariate model. Further, for JJA temperature prediction, the multivariate model with 6-month lead SST outstripped one-month lead prediction of global climate models. Therefore, the empirical-dynamical approach can pave a promising way for summer temperature prediction in South Korea.

This study was carried out to investigate the damage patterns, the occurrence and migration time of Pseudococcus comstocki and in order to improve the control effect of organic agricultural materials (OAMs). The experiment was carried out at Okcheon’s organic vineyard (2,500 ㎡, sandy loam, manure) where planted 8~9 year old ‘Muscat of Alexandria’ vines. The comstock mealybug’s migration to grape clusters occurred from the middle of July, and produced eggs in the grape clusters from the end of July, and the density of the comstock mealybug was highest at 0.6/㎠ in late August. The number and fruit damage of comstock mealybug in eco-friendly vineyards were higher than in conventional culture vineyard. And the marketability of green variety grape was more damaged from comstock mealybug than the black variety grape. Toxicities of 8 OAMs were evaluated to comstock mealybug at the recommended concentration. As a results, Lightyellow sophora and Derris extracts exhibited strong insecticidal activity with 100% mortality. When the Lightyellow sophora extract was uniformly distributed on the vine from early-July to mid-July, fruit damage reduction rate was 96.2% and 84.6%, respectively. So commercial grapes could be harvested. Therefore, it was considered to be effective to reduce fruit damage by controlling in early - late July (the green stage) when the comstock mealybug migrated to grape clusters in the vine greenhouse. In the future, it will be necessary to study the effect of external exposure time and momentum on the control of OAMs.

There is a rising interest of depletion of deposited fossil fuel and environmental pollution, inducing extensive studies to find new alternative sustainable energy sources to replace current petroleum based energy usage. As one of solutions, anaerobic digestion (AD) treating organic wastes has been considered one of the most promising processes owing to its sustainability, low production of sludge, unnecessariness of aeration, and biogas generation. Swine wastewater is characterized by high strength of organic matter contents, so it is regarded as a potential feedstock to produce methane through AD process. To investigate the functional relationship between the microbial communities and anaerobic process performance, regular seasonal sampling was done at four full scale anaerobic digesters treating swine wastewater in South Korea for two years. As results of process and microbial community analyses, chemical oxygen demand (COD) removal efficiency was monitored to proportional to those of carbohydrates, proteins and lipids. Methanogenic and bacterial populations were also positively related to the removal efficiencies of carbohydrates and lipids. However, proteins removal efficiency was independent of microbial population. It means that microbial communities in full scale anaerobic digesters are most likely to be mainly associated with carbohydrates and/or lipids metabolisms, indicating that proteins may be putative recalcitrant contents in wastewater. The microbial population tends to be more affected by places rather than seasons; however, with respect to seasons, the highest species abundances were observed mainly at winter. This implied that rising temperature in the anaerobic digesters in summer would be not suitable for the growth of mesophilic microorganisms, known to be predominant in anaerobic process. Actually, this speculation is supported by the fact that the highest removal efficiency of COD was measured at winter samples. The marked information in this study must provide a real insight into the effective field operation of anaerobic digestion.

이 논문에서는 동아시아적 자연학의 한 갈래이자 계절의 변화를 천 문기상학적 이론으로 접근시킨 고대 월령론이 성립하고 전개되는 문제 를 살펴보았다. 이때 고대 동아시아적 월령론이 정초되는 사상과 이론 의 기초로서 천문학과 기상학 관점의 논의를 주목하였고, 특히 계절의 변화에 따라 배태되는 자연물의 관찰경험적 지식이 광범위한 물후론으 로 성립하는 측면을 드러내고자 노력하였다. 이를 위해 본고에서는 먼저 그 계절의 변화론을 천문관측이론으로 설명하려는 상서 ｢요전｣의 사중성 문제를 살펴보았고, 이를 확대하 여 매월의 별자리 관찰과 물후로 연결시킨 대대례기 ｢하소정｣의 월 령론을 고찰하였다. 이어서 진제국의 통일이념서 역할을 하였던 여씨춘추 ｢십이기｣에 서 비로소 본격적인 1년 12월령 체계가 수립되었고, 이는 전한시기 회남자 ｢시칙훈｣과 예기 ｢월령편｣으로 계승되었는 바, 이 세 종류 문헌에 수록된 구체적인 천문과 물후월령의 관계를 살펴보았다. 이러는 사이에 월령론은 자연의 계절변화를 설명하는 적합한 이론틀 로 인식되고 확산되었으며, 그 끝에 후한대 성립으로 추정되는 일주서  ｢시훈해｣는 1년 12월 24절기 체제를 더욱 공고하게 만든 1년 72후법 을 처음으로 규범화하고 체계적 설명틀로 수립하였다. 이제 자연의 계 절 변화가 매뉴얼화되어 달력이 없더라도 규범화된 각 절기의 물후 곧 절후법을 통해 쉽게 자연의 변화를 인지하고 생활 속에서 활용할 수 있게 된 것이다. 그 72후의 절후법에는 1년 태양의 변화에 따라 규칙적으로 발생하는 기상상태와 동식물의 반응양태가 다분히 경험학적으로 반영되었으므 로 이 규범체계의 확산력은 매우 광범위하였다 하겠다. 남북조시대에 들어서 6세기 중반에 반포 사용된 위서 ｢정광력｣은 드디어 72절후법을 역법의 주요 요소로 평가하여 수록하였으며, 다만 일주서와는 다른 계통의 72후 체계를 엮어 제시하였다. 이후로 ｢역 지｣ 계통에는 반드시 72후법을 수록하는 것이 항례가 되었다. 수나라 의 <황극력 72후법>이나 당나라 전기의 <인덕력 72후법>은 이를 전승한 주요한 흐름들이며, 당나라 중기 <대연력 72후법>은 기존의 72후 순서나 내용을 다소 개변하였고, 당나라 후기 <선명력 72후법> 은 이 대연력 계통의 72후법을 전승한 것이었다. 우리나라의 경우 고려가 국초부터 당나라 <선명력>을 수용하여 사 용하였으므로, <선명력 72후법>의 이론으로 자연변화를 인식하고 설 명하였을 것이다. 고려말에 도입된 <수시력 72후법>은 기존의 72후 내용에 약간의 변화를 주었으며, 이 체계가 조선전기에도 습용되어 조 선의 학인들이 자연을 인식하는 주요 규범틀로 작용하기에 이르렀다. 이와 같이 72후에 기초한 물후월령은 월령론의 천문기상학적 접근 이자 전근대시대 자연의 변화를 해석하는 주요 통로로 기능하였다고 정리할 수 있다. 이에 따라 일상생활을 영위하는 우리로서 그 물후월령 을 통해 자연과 동화되고 적응하는 삶을 구가하는 것이며, 이는 달리 말하면 우리의 일상생활을 우주론적으로 성화시키는 자연학적 기제가 여기에 놓인 것이라 이를 수가 있을 것이다. 이런 측면에서 본고의 논의 는 월령자연학으로 열리는 방향이라 하겠다. 조선 후기에 널리 성립하는 각종 세시기 문헌의 세시월령이나 각종 시가 작품으로 전하는 월령체 문학 또는 각종 구비전승으로 전개되는 민속월령 문화는 우리 문화사를 구성하는 주요 영역인 바, 그 문화의 기초가 되는 월령자연학의 역사적 흐름과 이에 대한 천문기상학적 원 리 해명을 시도한 것이 본고의 주요 관심사이자 연구 의의라 이를 수 있다.

2014년부터 기상청에서 현업으로 활용하고 있는 전지구 계절예측시스템 GloSea5의 최대 6개월 예측 강수량을 수자원 및 여러 응용분야에 활 용하기 위해서는 예측모델이 가지는 관측자료와의 정량적인 편의를 보정할 필요가 있다. 본 연구에서는 GloSea5의 예측 강수량에서 나타나는 편 의를 보정하기 위해 확률분포형을 활용한 편의보정기법, 매개변수 및 비매개변수적 편의보정기법 등 총 11개의 기법을 활용하여 계절예측모델의 적용성을 평가하고 최적의 편의보정기법을 선정하고자 하였다. 과거재현기간에 대한 편의보정 결과, 비매개변수적 편의보정기법이 다른 기법에 비해 가장 관측자료와 유사하게 보정하는 것으로 분석되었으나 예측기간에 대해서는 상대적으로 많은 이상치를 발생시켰다. 이와는 대조적으로 매개변수적 편의보정기법은 과거재현기간 및 예측기간 모두 안정된 결과를 보여주고 있음을 확인할 수 있었다. 본 연구의 결과는 수자원운영 및 관 리, 수력, 농업 등 계절예측모델을 활용한 여러 응용분야에 적용이 가능할 것으로 기대된다.

본 연구는 소과종 수박의 병해충 발생 양상을 조사하고 이중 가장 문제가 되는 병 들 중 의 하나인 흰가루병을 방제하기 위한 유기농업자재를 선발하기 위하여 수행되었다. 2015년 충북 음성에서 소과종 수박에 발생하는 병해충 조사 결과 덩굴마름병, 흰가루병, 목화진딧 물, 점박이응애, 총채벌레류, 파밤나방, 담배거세미나방 등 일반수박에 발생하여 피해를 주 는 대부분의 병해충이 발생하는 것을 확인할 수 있었다. 이중 흰가루병은 6월 중순에 품종 별로 27~99.3%의 발생률을 나타냈으며 점박이응애는 6월 중순에 품종별로 엽당 마릿수가 79.9~111마리로 높은 발생을 보였다. 또한, 총채벌레류는 6월 중순과 상순에 황색과 청색 평판점착트랩 각각에 트랩당 407마리와 774마리로 높은 유살수를 나타냈다. 포장에서 마 요네즈와 올레산 그리고 현재 시판 중인 유기농업자재 3종에 대한 흰가루병 방제 효과를 조사하였다. 조사 결과 sodium bicarbonate 80%가 함유된 자재, 마요네즈 그리고 대황추출 물 1%가 함유된 자재가 60% 이상까지 효과적으로 병 발생을 감소시켰으며, 이중 sodium bicarbonate 80%가 함유된 자재가 83%로 가장 높은 방제가를 나타냈다. 본 연구를 통해 소 과종에 발생하는 병해충에 대한 정보와 sodium bicarbonate 80% 함유 자재가 흰가루병 방제 에 효과적이라는 것을 알 수 있었다.

본 시험은 전국의 광역친환경 농업단지 중에서 모범적으로 친환경 농업을 실천하고 있 는 3곳(장흥, 순천, 옥천)의 벼 농가를 대상으로 시기별로 양분 분석을 하였다. 장흥지역 농 가만이 경축자원 순환농업을 실천하고 있는 것으로 관찰되었다. 광역친환경 벼 농업단지의 3~9월 사이의 시기별 토양 pH는 5.5~6.7의 분포를 보였고, EC는 0.4~1.0 dS m-1으로 나타났 다. 시기별 토양 전질소는 순천 농가에서 높았고 칼륨은 옥천 농가에서 낮은 수준을 보였 다. 시기별 토양 암모늄태 질소는 봄철 비료 시용으로 6월 전후에 상승하였고, 장흥 농가에 서 가장 높은 수준을 보이다가 이후 크게 감소하였다. 수량과 수확지수가 가장 높았던 옥 천 농가에서 ha당 연간 조수입이 다른 농가보다 세배 가까이 높은 수준을 보였다. 비교적 많은 비료를 투입한 옥천 농가에서 시기별 양분수지가 높았고, 순천 농가의 ha당 칼륨 수지 는 9월에 약 -60 kg까지 관찰되어 칼륨 결핍에 따른 생산성 저하에 일부 영향을 주었을 것 으로 추정되었다. 시기별 전질소와 인산수지는 장흥 농가에서 가장 낮은 수준을 보였고 벼 낟알의 질소이용효율도 가장 높아서 광역친환경 농업단지의 추천할 만한 사례 농가로 평 가되었다.