• Food Science and Preservation
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• v.4 no.1
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• pp.53-59
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• 1997

Physicochemical properties affecting on the quality of Citrus unshiu Marc. var miyagawa and C. unshiu Marc. var, okitsu according to cultivation area in Cheju were investigated. Linear correlations (r>0.9) were showed between fruit size and peel thickness. There were much difference between cultivation areas in soluble solids of C. unshiu Marc. var. okitsu. The difference were not so much in soluble solids and acid contents of citrus fruits produced at same area below 65mm of fruit diameter, but the quality of large size fruits were inferior. Brix/Acid ratio could not be index for quality evaluation, because of individual deviation. Soluble solid content of citrus fruits produced in south Cheju was higher than that produced in north Cheju. Acid content and Brix/Acid ratio of citrus fruits produced in south Cheju was lower than that produced in north Cheju. The quality of C. unshiu Marc. var. miyagawa clad not so much difference between cultivation area, but the difference of quality were recognized significantly in C. unshiu Marc. var. okitsu.

• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.425-434
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• 2013

Nowadays, the korean peninsula has endured weather changes toward to the subtropical climate. Also demographical structure has changed into multi-cultural society in which many people from subtropical areas have immigrated into Korea. Therefore, consumption and production of subtropical vegetables become important. For the analysis, we choose eight important subtropical crops. EDM (Equilibrium Displacement Model) with many parameters and elasticities is used for the forecast of consumption and required cultivation area. The simulation focuses on the changes of the number of foreign workers and immigrated women in Korea to predict the quantity of consumption and required area in Korea. The results show that we need additional land area about 581~1,065 ha for the cropping subtropical vegetables in Korea. Finally, these required area can be provided by the cities and counties in coast area in Gyeongsangnam-Do, Jeonranam-Do and Jeju-Do. Climate change will be continued in the future. Together with climate change, the change of demographical structure into multi-culture may increase consumption and production of subtropical vegetables. Forecasting of increased consumption and required cultivation area for subtropical vegetables is significant.

• Korean Journal of Environmental Agriculture
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• v.37 no.3
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• pp.160-165
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• 2018

BACKGROUND: Mixed cropping of legume and grass was effective system in view point of providing organic matter and nitrogen or reducing the nitrogen starvation of following crop. The relation of the change of N and P constituents depending on the cropping types and those effects on the growth and nutrient uptake of the following crop were observed. METHODS AND RESULTS: Three cropping types, hairy vetch mono cropping, barley mono cropping, and mixed cropping of hairy vetch and barley were applied. Soil properties, growth characteristics, and nitrogen production of green manure crops were observed. In additions, the effect of cropping types on the growth pattern of corn as the following crop was observed. In the mixed cropping system, creeping type hairy vetch climbed to the erect type barely for light utilization resulting in improvement of light interception rate and higher LAI (Leaf Area Index) than in mono cropping. Mixed cropping showed higher biomass production and soil nitrogen availability among the cropping types, indicating relatively much more nutrient supply and higher yield production of following crop. CONCLUSION: Mixed cropping showed relatively higher LAI (dry matter) mainly because of intense competition for light utilization usually after flowering stage. Mixed cropping also showed relatively higher yield of corn, the following crop rather than other types, mainly due to the more biomass production potential and higher N and P production ability. Therefore, mixed cropping was adaptable method to reduce or replace chemical fertilizer application for environmentally-friendly agriculture.

• Proceedings of the Korean Society of Crop Science Conference
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• 2019.04a
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• pp.38-38
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• 2019

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.123-123
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• 2022

In order to evaluate the effect of nitrogen application levels on yield and protein content of rice varieties, a field experiment was conducted at National Institute of Crop Science of Korea in 2020. Five levels(0, 3, 5, 7, and 9 kg·10a^-1) of nitrogen fertilizer were treated to six Korean rice varieties. The nitrogen uptake amount, soil nitrogen content before and after rice cultivation, milled rice yield, and protein content in head rice were analyzed. As the treatment of nitrogen fertilizer increased, the nitrogen uptake amount of plants increased significantly. However, changes in nitrogen content in the soil before and after rice cultivation were different for each cultivar. The amount of nitrogen change in the soil decreased as the amount of nitrogen application increased in the three cultivars of Haepum, Gopum, and Odae, and the other three cultivars showed the opposite trend. As a result of correlation analysis of nitrogen application amount, nitrogen uptake amount, milled rice yield, and protein content of head rice, the five varieties except for Haepum showed a high correlation between these factors. The amount of nitrogen application and nitrogen uptake of plant showed a positive correlation about the milled rice yield and protein content of head rice. In particular, the protein content in head rice appeared to be more affected by nitrogen uptake amount than nitrogen application amount. As a result of this study, the yield and protein content of rice had positive correlations with the level of nitrogen fertilizer, and had a high correlation with the nitrogen absorption of plants.

• The Korean Journal of Food And Nutrition
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• v.31 no.4
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• pp.502-510
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• 2018

To begin with, this study identified and reviewed the proximate compositions, quality and physicochemical characteristics of three Korean cowpea (Vigna unguiculata L. Walp.) cultivars grown in two different seedling periods. The proximate compositions of the cowpea showed significant differences according to three cultivars (Seowon, Yeonboon and Okdang) and two different seeding periods (5 June and 5 July). Through this lens, the lightness, redness and yellowness of the cowpea cultivars increased slightly during the 5 July cultivation compared to the 5 June cultivation. This brings us to understand that the water binding capacity, water solubility index, and swelling power were significantly different among the cultivars. In this case, the water binding capacity of the cowpea was 108.87~143.19%, and decreased during the 5 July cultivation compared to the 5 June cultivation. As shown, the total polyphenol and flavonoid contents of cowpea showed significant difference according to cultivars. In this case, the total polyphenol content of 5 June and 5 July cultivation on the Seowon 4.17 and 4.12 mg GAE/g, respectively. In these terms, the DPPH radical scavenging activity of cowpea showed a significant difference according to the cultivars, and the Yeonboon and Okdang increased slightly during 5 July cultivation. The ABTS radical scavenging activity of the cowpea showed significant difference according to the cultivars, and all cultivars decreased slightly during the 5 July cultivation. In other words, the phenol contents and radical scavenging activity differ measurable depending on the cultivars and seeding periods. Therefore, it is necessary to study the proper cultivar and seeding time considering the environment of the applicable cultivation area.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.6
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• pp.13-23
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• 2022

The purpose of this study was to analyze the impact of greenhouse cultivation area and groundwater level changes due to the water curtain cultivation in the greenhouse complexes, which are mainly situated along rivers where water resources are easy to secure. The groundwater observation network in Miryang, Gyeongsangnam-do, located downstream of the Nakdong River, was selected for the study area. We classified the groundwater monitoring well into the greenhouse (riverside) and field cultivation areas (plain and mountain) to compare the groundwater impact of water curtain cultivation in the greenhouse complex. The characteristics of groundwater level changes classified by terrain type were analyzed using the observed data. Riverside wells have significant permeability coefficients and are close to rivers, so they are greatly affected by river flow and precipitation changes so that water level shows a specific pattern of annual changes. Most plain wells do not show a constant annual change, but observation wells near small rivers and small-scale greenhouse cultivation areas sometimes show annual and daily changes in which the water level drops during winter. Compared to other observation wells, mountain wells do not show significant yearly changes in water level and show general characteristics of bedrock aquifer well with a low permeability coefficient.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.2
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• pp.1-11
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• 2023

This study analyzed the impact of greenhouse cultivation area and groundwater level changes due to the water curtain cultivation in the greenhouse complexes. The groundwater observation data in the Miryang study area were used and classified into greenhouse and field cultivation areas to compare the groundwater impact of water curtain cultivation in the greenhouse complex. We identified the characteristics of the groundwater time series data by the terrain of the study area and selected the optimal model through time series analysis. We analyzed the time series data for each terrain's two representative groundwater observation wells. The Seasonal ARIMA model was chosen as the optimal model for riverside well, and for plain and mountain well, the ARIMA model and Seasonal ARIMA model were selected as the optimal model. A suitable prediction model is not limited to one model due to a change in a groundwater level fluctuation pattern caused by a surrounding environment change but may change over time. Therefore, it is necessary to periodically check and revise the optimal model rather than continuously applying one selected ARIMA model. Groundwater forecasting results through time series analysis can be used for sustainable groundwater resource management.

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.22-22
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• 2020

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.11a
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• pp.45-45
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• 2020