• 농업과학연구
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• 제41권4호
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• pp.341-350
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• 2014

The occurrence of insect pests of Lycium chinense was monitored at 4 organic farms that was cultivated with environment-friendly management at Cheongyang, Chungnam from May, 2012 to September, 2014. Total 4 orders and 18 species occurred in the L. chinense. Among them, 4 major pests and Lepidopteran and Hemipteran insect pests were investigated the occurrence pattern. During the budding, the population density of Myzus persicae was very high in late-May and early-June, and the injury by Lema decempunctata was increased from mid-June. The injuries by Henosepilachna vigintioctomaculata and Hedma lycia sp. were continued throughout the growing season. From the fruit held in late-July, hemipteran insects including Plautia stali and Halyomorpba balys were sucking the fruit, and their injury to L. chinense were gradually increased. In the case of Eriophys macrodonis densities to increase gradually from early July. The population density of E. macrodonis in 2014 was rapidly increased more than 5 times compared with 2012 and 2013. It was supposed that the initial control of mites or the removing of over-wintering density in the past year might be neglected. However, there is a need to more review the factors for the mass occurs.

• Spatial Information Research
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• 제14권4호
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• pp.363-377
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• 2006

본 연구에서는 개정범용토양유실공식(RUSLE: Revised Universal Soil Loss Equation)을 이용하여 미국 South Carolina 주 Congaree 유역에 대한 평균 연간 토양 유실량을 산출 하였으며 비점오염원 토양 유실 민감지역을 추출하였다. 평균 연간 토양 유실량은 강우-유출 침식성 인자, 토양침식성 인자, 지면특성 인자, 식생피복 인자, 그리고 토양보존 인자의 곱으로 계산할 수 있으며, 토양 유실 민감지역은 토양 유실량이 토양침식 허용량을 초과하는 지역으로 추출할 수 있다. 연구 결과, 전체 면적의 10% 이상의 면적이 비점오염원 토양 유실 민감 지역으로 확인되었으며, Congaree 유역의 7개 소유역중 Congaree Creek, Gills Creek 소유역의 도심지역과 Cedar Creek 소유역의 농업지역에서 가장 심각한 토양 유실의 위험이 나타났다. 관심 지역의 인위적, 자연적 변화가 토양 유실에 가져오는 영향을 살펴보기 위한 시범 모형으로서, 개정범용토양유실공식에 기초한 내장형 모형이 Visual Basic for Applications (VBA)를 이용하여 ESRI사의 ArcGIS ArcMap 9.0에서 사용할 수 있도록 개발되었다. 이 내장형 모형에서 사용자는 각 소유역의 토지 피복, 식생 유형, 지표 식생 유형, 경사, 작물 유형, 경작 방식 등을 변경시킴으로써 C, LS, P 인자를 변화시킬 수 있으며, 계산된 평균 연간 토양 유실량과 민감 지역을 현재 상태의 값들과 비교하여 앞으로의 토양유실 관리를 위한 주요 정보로 사용할 수 있다.

• 한국환경농학회지
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• 제38권4호
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• pp.219-224
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• 2019

BACKGROUND: Soil bacteria play important roles in organic matter decomposition and nutrient cycling during the non-growing season. The purpose of this study was to investigate the effects of soil management and chemical properties on the utilization of carbon sources by soil bacteria in paddy fields. METHODS AND RESULTS: The Biolog EcoPlate was used for analyzing community-level carbon substrate utilization profiles of soil bacteria. Soils were collected from the following three types of areas: plain, interface and mountain areas, which were tested to investigate the topology effect. The results of canonical correspondence analysis and Kendall rank correlation analysis showed that soil C/N ratio and NH₄⁺ influenced utilization of carbon sources by bacteria. The utilization of carbohydrates and complex carbon sources were positively correlated with NH₄⁺ concentration. Cultivated paddy fields were compared with adjacent abandoned fields to investigate the impact of cultivation cessation. The level of utilization of putrescine was lower in abandoned fields than in cultivated fields. Monoculture fields were compared with double cropping fields cultivated with barley to investigate the impact of winter crop cultivation. Cropping system altered bacterial use of carbon sources, as reflected by the enhanced utilization of 2-hydroxy benzoic acid under monoculture conditions. CONCLUSION: These results show that soil use intensity and topological characteristics have a minimal impact on soil bacterial functioning in relation to carbon substrate utilization. Moreover, soil chemical properties were found to be important factors determining the physiological profile of the soil bacterial community in paddy fields.

• 한국환경과학회지
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• 제26권11호
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• pp.1255-1266
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• 2017

Phosphorus (P) is an essential and major nutrient for both plants and animals. However, anthropogenic P in the environment may cause severe problems such as the deterioration of water quality. Therefore, it is essential for the Korean government to manage P in the agricultural sector. The annual P budget for Korea was 46 kg P ha-1 in 2013, placing Korea in second among Organisation for Economic Co-operation and Development (OECD) countries. P surplus and deficiency in agricultural lands can be estimated according to the P budget, which is one of the OECD agri-environment indicators. In the P budget, it is important to ensure consistency in the input-output data sources, in order to apply national and regional policies for the environmentally sound management of agricultural P. This study examines the impacts on the input-output data sources in the regional P budget in Korea. P budgets were between 99-145 kg-P/ha, depending on different data sources. We suggest two recommended data combinations (DC 1 and DC 2) for reliability of the data. P budgets calculated using DC 1 and DC 2 were 128 kg-P/ha and 97 kg-P/ha, respectively. According to the results, one of the core factors affecting P budgets was crop production. In this study, DC 2 was recommended rather than DC 1 in order to consider the cultivated areas for various crops. It is also necessary to analyze the sensitivity of the coefficients used in P budget in the future.

• The Plant Pathology Journal
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• 제33권6호
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• pp.543-553
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• 2017

Sesame (Sesamum indicum) is an important oil seed crop of Asia. Yields can be negatively impacted by various factors, including disease, particularly those caused by fungi which create problems in both production and storage. Foliar diseases of sesame such as Alternaria leaf blight may cause significant yield losses, with reductions in plant health and seed quality. The work reported here determined the incidence of Alternaria species infecting sesame seeds grown in the Punjab, Pakistan. A total of 428 Alternaria isolates were obtained from 105 seed samples and grouped into 36 distinct taxonomic groups based on growth pattern and morphological characters. Isolation frequency and relative density of surface sterilized and non-surface sterilized seeds showed that three isolates (A13, A47 and A215) were the most common morphological groups present. These isolates were further identified using sequencing of the Internal Transcribed Spacer (ITS) region of ribosomal DNA (rDNA) and the Alternaria major allergen gene (Alt a 1). Whilst ITS of rDNA did not resolve the isolates into Alternaria species, the Alt a 1 sequences exhibited > 99% homology with Alternaria alternata (KP123850.1) in GenBank accessions. The pathogenicity and virulence of these isolates of Alternaria alternata was confirmed in inoculations of sesame plants resulting in typical symptoms of leaf blight disease. This work confirms the identity of a major source of sesame leaf blight in Pakistan which will aid in formulating effective disease management strategies.

• Journal of Biosystems Engineering
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• 제39권4호
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• pp.377-388
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• 2014

Purpose: Determining the spatial structure of data is important in understanding within-field variability for site-specific crop management. An understanding of the spatial structures present in the data may help illuminate interrelationships that are important in subsequent explanatory analyses, especially when site variables are correlated or are a combined response to multiple causative factors. Methods: In this study, correlation, principal component analysis, and single and nested variogram models were applied to soil electrical conductivity and chemical property data of two fields in central Missouri, USA. Results: Some variables that were highly correlated, or were strongly expressed in the same principal component, exhibited similar spatial ranges when fitted with a single variogram model. However, single variogram results were dependent on the active lag distance used, with short distances (30 m) required to fit short-range variability. Longer active lag distances only revealed long-range spatial components. Nested models generally yielded a better fit than single models for sensor-based conductivity data, where multiple scales of spatial structure were apparent. Gaussian-spherical nested models fit well to the data at both short (30 m) and long (300 m) active lag distances, generally capturing both short-range and long-range spatial components. As soil conductivity relates strongly to profile texture, we hypothesize that the short-range components may relate to the scale of erosion processes, while the long-range components are indicative of the scale of landscape morphology. Conclusion: In this study, we investigated the effect of changing active lag distance on the calculation of the range parameter. Future work investigating scale effects on other variogram parameters, including nugget and sill variances, may lead to better model selection and interpretation. Once this is achieved, separation of nested spatial components by factorial kriging may help to better define the correlations existing between spatial datasets.

• 한국농공학회논문집
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• 제57권5호
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• pp.129-137
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• 2015

The objective of this study was to test the non-point source pollution (NPS) control by the vegetated ridge and silt fence through field monitoring. The experiment plots were established with three sizes which are 5 m width by 22 m length with 8 %, 3 % slope and 15m width by 15 m length with 6 % slope. Flumes with the floating type stage gages were installed at the outlet of each plot to monitor the runoff. For a rainfall monitoring, tipping bucket rain gage was installed within the experiment site. Water quality samples were monitored during the heavy rainfall occurred. The amount of rainfall from 4 monitored events ranged from 27.6 mm to 130 mm. The runoff reduction rate could vary depending on slope, soil, crop growth condition, rainfall amount, rainfall intensity, antecedent moisture condition, and many other factors. The runoff from vegetated ridge and silt fence treatment plots was 24.05 % and -8.28 % lower than that from control plot, respectively. The monitoring results showed that the average pollution loads reduced by vegetated ridge compared to control were BOD 36.62~53.60 %, SS 40.41~73.71 %, COD 39.34~56.41 %, DOC 49.08~53.67 %, TN 26.74~67.23 %, and TP 52.72~91.80 %; by silt fence compared to control were SS 41.73 %, COD 1.93 %, and TN 2.38 %. The paired t-test result indicated that the vegetated ridge and silt fence were statistically significant effect in SS load reduction, with a 5 % significant level. Monitored results indicated that vegetated ridge and silt fence were both effective to reduce the pollutant from the field surface runoff.

• Agribusiness and Information Management
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• 제8권2호
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• pp.1-8
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• 2016

The present study has aimed at analyzing the technical and scale efficiencies of credit utilization by the farmer-borrowers in Chittoor district of Andhra Pradesh, India. DEA approach was followed to analyze the credit utilization efficiency and to analyze the factors influencing the credit utilization efficiency, log-linear regression analysis was attempted. DEA analysis revealed that, the number of farmers operating at CRS are more in number in marginal farms (40%) followed by other (35%) and small (17.5%) farms. Regarding the number of farmers operating at VRS, small farmers dominate the scenario with 72.5 per cent followed by other (67.5%) and marginal (42.5%) farmers. With reference to scale efficiency, marginal farmers are in majority (52.5%) followed by other (47.5%) and small (25%) farmers. At the pooled level, 26.7 per cent of the farmers are being operated at CRS, 63 per cent at VRS and 32.5 per cent of the farmers are either performed at the optimum scale or were close to the optimum scale (farms having scale efficiency values equal to or more than 0.90). Nearly 58, 15 and 28 percents of the farmers in the marginal farms category were found operating in the region of increasing, decreasing and constant returns respectively. Compared to marginal farmers category, there are less number of farmers operating at CRS both in small farmers category (15%) and other farmers category (22.5%). At the pooled level, only 5 per cent of the farmers are operating at DRS, majority of the farmers (73%) are operating at IRS and only 22 per cent of the farmers are operating at CRS indicating efficient utilization of credit. The log-linear regression model fitted to analyze the major determinants of credit utilization (technical) efficiency of farmer-borrowers revealed that, the three variables viz., cost of cultivation and family expenditure (both negatively influencing at 1% significant level) and family income (positively influencing at 1% significant level) are the major determinants of credit utilization efficiency across all the selected farmers categories and at pooled level. The analysis further indicate that, escalation in the cost of cultivation of crop enterprises in the region, rise in family expenditure and prior indebtedness of the farmers are showing adverse influence on the credit utilization efficiency of the farmer-borrowers.

• The Plant Pathology Journal
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• 제37권6호
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• pp.521-532
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• 2021

Knowledge and better understanding of functions of the microbial community are pivotal for crop management. This study was conducted to study bacterial structures including Acidovorax species community structures and diversity from the watermelon cultivated soils in different regions of South Korea. In this study, soil samples were collected from watermelon cultivation areas from various places of South Korea and microbiome analysis was performed to analyze bacterial communities including Acidovorax species community. Next generation sequencing (NGS) was performed by extracting genomic DNA from 92 soil samples from 8 different provinces using a fast genomic DNA extraction kit. NGS data analysis results revealed that, total, 39,367 operational taxonomic unit (OTU), were obtained. NGS data results revealed that, most dominant phylum in all the soil samples was Proteobacteria (37.3%). In addition, most abundant genus was Acidobacterium (1.8%) in all the samples. In order to analyze species diversity among the collected soil samples, OTUs, community diversity, and Shannon index were measured. Shannon (9.297) and inverse Simpson (0.996) were found to have the highest diversity scores in the greenhouse soil sample of Gyeonggi-do province (GG4). Results from NGS sequencing suggest that, most of the soil samples consists of similar trend of bacterial community and diversity. Environmental factors play a key role in shaping the bacterial community and diversity. In order to address this statement, further correlation analysis between soil physical and chemical parameters with dominant bacterial community will be carried out to observe their interactions.

• Agribusiness and Information Management
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• 제8권1호
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• pp.17-26
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• 2016

India is largest producer of banana in the world producing 29.72 million tonnes from an area of 0.803 million ha with a productivity of 35.7 MT ha-1 and accounted for 15.48 and 27.01 per cent of the world's area and production respectively (www.nhb.gov.in). In India, Tamil Nadu leads other states both in terms of area and production followed by Maharashtra, Gujarat and Andhra Pradesh. In Rayalaseema region of Andhra Pradesh, Kurnool district had special reputation in the cultivation of banana in an area of 5765 hectares with an annual production of 2.01 lakh tonnes in the year 2012-13 and hence, it was purposively chosen for the study. On $23^{rd}$ November 2003, the Government of Andhra Pradesh has commenced a comprehensive project called 'Andhra Pradesh Micro Irrigation Project (APMIP)', first of its kind in the world so as to promote water use efficiency. APMIP is offering 100 per cent of subsidy in case of SC, ST and 90 per cent in case of other categories of farmers up to 5.0 acres of land. In case of acreage between 5-10 acres, 70 per cent subsidy and acreage above 10, 50 per cent of subsidy is given to the farmer beneficiaries. The sampling frame consists of Kurnool district, two mandals, four villages and 180 sample farmers comprising of 60 farmers each from Marginal (<1ha), Small (1-2ha) and Other (>2ha) categories. A well structured pre-tested schedule was employed to collect the requisite information pertaining to the performance of drip irrigation among the sample farmers and Data Envelopment Analysis (DEA) model was employed to analyze the performance of drip irrigation in banana farms. The performance of drip irrigation was assessed based on the parameters like: Land Development Works (LDW), Fertigation costs (FC), Volume of water supplied (VWS), Annual maintenance costs of drip irrigation (AMC), Economic Status of the farmer (ES), Crop Productivity (CP) etc. The first four parameters are considered as inputs and last two as outputs for DEA modelling purposes. The findings revealed that, the number of farms operating at CRS are more in number in other farms (46.66%) followed by marginal (45%) and small farms (28.33%). Similarly, regarding the number of farmers operating at VRS, the other farms are again more in number with 61.66 per cent followed by marginal (53.33%) and small farms (35%). With reference to scale efficiency, marginal farms dominate the scenario with 57 per cent followed by others (55%) and small farms (50%). At pooled level, 26.11 per cent of the farms are being operated at CRS with an average technical efficiency score of 0.6138 i.e., 47 out of 180 farms. Nearly 40 per cent of the farmers at pooled level are being operated at VRS with an average technical efficiency score of 0.7241. As regards to scale efficiency, nearly 52 per cent of the farmers (94 out of 180 farmers) at pooled level, either performed at the optimum scale or were close to the optimum scale (farms having scale efficiency values equal to or more than 0.90). Majority of the farms (39.44%) are operating at IRS and only 29 per cent of the farmers are operating at DRS. This signifies that, more resources should be provided to these farms operating at IRS and the same should be decreased towards the farms operating at DRS. Nearly 32 per cent of the farms are operating at CRS indicating efficient utilization of resources. Log linear regression model was used to analyze the major determinants of input use efficiency in banana farms. The input variables considered under DEA model were again considered as influential factors for the CRS obtained for the three categories of farmers. Volume of water supplied ($X_1$) and fertigation cost ($X_2$) are the major determinants of banana farms across all the farmer categories and even at pooled level. In view of their positive influence on the CRS, it is essential to strengthen modern irrigation infrastructure like drip irrigation and offer more fertilizer subsidies to the farmer to enhance the crop production on cost-effective basis in Kurnool district of Andhra Pradesh, India. This study further suggests that, the present era of Information Technology will help the irrigation management in the context of generating new techniques, extension, adoption and information. It will also guide the farmers in irrigation scheduling and quantifying the irrigation water requirements in accordance with the water availability in a particular season. So, it is high time for the Government of India to pay adequate attention towards the applications of 'Information and Communication Technology (ICT) and its applications in irrigation water management' for facilitating the deployment of Decision Supports Systems (DSSs) at various levels of planning and management of water resources in the country.