• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.696-701
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• 2011

This study was conducted to investigate impacts of soil properties on microbial distribution in Jeonbuk orchard fields. Soil samples were collected from 110 sites cultivated with different fruit plants. The population of aerobic bacteria and fungi and the content of soil microbial biomass carbon (C) were found to increase with increasing silt content in the soils. Different activity of dehydrogenase was not observed among the different textures of soil. Microbial distribution, amount of microbial biomass C, and dehydrogenase activity in the soils were not significantly different among the topographic sites. However, in pear and grape fruit plant fields, coliform group of bacteria was found in relatively higher population, $133.0{\times}10^3\;CFU\;g^{-1}$ and $107.4{\times}10^3\;CFU\;g^{-1}$, respectively. Microbial groups were simplified and their density was reduced with increasing the cultivation periods of fruit plants. The soil microbial distribution was proportionally correlated with some of soil properties such as soil pH, soil organic matter (SOM) content, and exchangeable Mg content; in particular, the population of Bacillus sp. was proportionally correlated with soil pH and exchangeable Mg content. The amounts of microbial biomass C and the dehydrogenase activity in the soils were significantly correlated with the contents of SOM and exchangeable Ca ion (p<0.01).

• Korean Journal of Environmental Agriculture
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• v.41 no.3
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• pp.158-166
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• 2022

BACKGROUND: Kiwifruit is a fruit tree with relatively small cultivation area in Korea and researches on its soil and physiology are very limited compared to those on cultivar development. Therefore, there are limited information for farmers to cope with the reduction in productivity due to various physiological disorders and premature aging. This study was conducted to investigate the soil and leaf chemical properties, and fruit characteristics, which will be used as basic data for stable kiwifruit orchard soil management. METHODS AND RESULTS: The soil and leaf chemical properties, and fruit characteristics were investigated for two years in 16 kiwifruit orchards growing 'Hayward' (Actinidia deliciosa) in Jeollanam-do and Gyeongsangnam-do. Soil and leaf samples were collected in July and fruit quality was investigated by harvesting fruits about 170 days after full bloom. The average soil chemical properties of kiwi orchards were generally higher than the recommended level, except for pH, and especially, the exchangeable potassium reached about 300% of the recommended level. The proportions of orchards that exceeded the recommended level of soil chemical properties were 63, 31, 100, 69, 94, 88 and 69% for pH, EC, organic content, available phosphate, and exchangeable potassium, calcium and magnesium, respectively. Thirty-three percent of orchards had more than 100 mg/kg of nitrate nitrogen in soil. Available phosphate in soil showed a significantly positive correlation with leaf nitrogen, phosphoric acid and calcium content, but showed a significantly negative correlation with leaf potassium content. The magnesium content in the leaves was significantly correlated with soil pH. The highest fruit weight was observed in about 25 g/kg of leaf nitrogen content which could be attained when plants were grown on the soil containing about 100 mg/kg of nitrate nitrogen content. The average soluble solids content among 16 orchards was 9.58 °Brix at harvest and 13.9 °Brix after ripening, which increased about 45%, and the average fruit weight was about 110 g. CONCLUSION(S): For fruit quality, fruit soluble solids (sugar compounds) content was significantly correlated with leaf potassium content, fruit hardiness with leaf total nitrate, calcium and magnesium, and fruit titratable acidity with leaf magnesium; however, leaf calcium and magnesium negatively affect the soluble solids contents in fruits.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.3
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• pp.2349-2371
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• 1971

1. The historical development of the agriculture in Korea is observed and the future of Korean agriculture is suggested with present situation in order to recommend a direction of policy in agricultural mechanization. 2. A factor analysis of agricultural mechanization The needs of agricultural mechanization in the view of both national need and the armer's desire under the present situation are analyzed with data from the various sources. The researcher found that the agricultural mechanization is badly needed to develop prospective Korean agriculture to future. 3. The direction of agricultural mechanization. It can be said that the position of agriculture in the national economy plays a very important role. This importance should not be ignored by the Politicians in their process of developing long range economy plan. The agricultural mechanization for the modernized Korean agriculture should be directed to increase the most effective results with minimize the least sacrifice. The merry tiller is recommended to the main agricultural machinery in Korea in order to meet its small farming operation un-its(or farm size). Tractor is recommended in the plain area for the crop cultivation. The cooperative cultivation for rice and the upland crops will be developed in the plain area. Tractor, therefore, is recommended for the main agricultural machinery in these areas. Either tractor or merry tiller is recommended to the orchard area by its operating size of the orchard. The researcher also disoussed about the development of animal husbandry on the farm with increasing the farm size in order to develop meadow and pasture nuder the consideration of both the improvement of food consumption and the comprehensive development of national resources. 4. Relationship between the Performance of various agricultural machinery and the economic scale. Because of the agricultural machinery needs an expensive fixed expense(fixed cost) the total expense Per ha of the fixed expense and the operation expense should less than the traditional expense Per Dan Bo with in creased corpgiclds Per Dan Bo. Since the anual fixed expense of the agricultural machinery is figured out by the durability the more the farm size the less fixed expense of machinery is required. The formula of this principle is as follows; fixed expense for Dan Bo=Fixed expense of agricultural machinery farm size(or farming scale) The breaking-even point is the balance point between the expense of the using agricultural machinery and the traditional farming expenses. Labor cost of the Dan Bo is increasing when the management scale increases by the tradititional farming while the machanized management decrease the management cost Per Dan Bo. The reseracher found that the distribution of agricultural machinery will be the adeventeous after the year of 1981 by the result of frguring out the breaking-even point. 5. The Investigate and the conclusion. The purpose of this study is found out the direction of agricultural machanization and the breaking-even point of various agricultural machinery, there for is found out effective of the using various agricultural machinery for Collection cutter, Binder, Footing thresser, Semi-power thresser, Power thresser, Combine, Power rice-Trans-Planter, etc.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.3
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• pp.280-287
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• 1997

This study was carried out to investigate agricultural status and soil fertility of Bonghwang-cheon watershed area which is located at Chodong-myeon, Milyang-si. The acreage of arable land was about 1,209ha, and the population was 3,706 people. Out of total arable land, paddy was 64.4%, upland 19.6% and orchard 16.0%. Chicken was the largest in the number of livestock and poultry, but pig seems to contribute most severly to water pollution. The geology in the lower stream was alluvium but andesite and derivated materials from it were occupied most upland areas. Tuff was scattered in the small area near by the alluvium of Nakdong river, and diorite and granodiorite were located at the low hill and mountains respectivately. The principal paddy soils in the area were Geumgog, Jisan and Imgog series etc of fine loamy on sloped valleys and fans. The Pyeongtaeg series, fine silty family of imperfectly drained on plain was irrigated by Chodong reservoir. The clayey Honam series on alluvium was distributed along the low hill while Gyuam series, coarse silty alluvial soil way close to Nakdong river. In chemical properties of soils, the vinyl house soils were higher in EC, and orchard soils in OM, $P_2O_5$, exchangeable canons than other soils.

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.59-66
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• 2006

The damaged area by and the distribution of Japanese gall forming thrips, Ponticulothrips diospyrosi Haga et Okajima (Thysanoptera: Phlaeothripidae) in Korea were surveyed based on the answers of persimmon growers to questionnaire. Seasonal occurrence of each developmental stage was estimated by monitoring the individuals in damaged leaves, and effect of trap site and side of sticky board were studied by yellow sticky traps at three sweet persimmon orchards in Gimhae and Jinju (orchards A and B), Gyeongnam province, Korea in 2005. P. diospyrosi gave damage to astringent persimmon as well as sweet one. The damaged area of persimmon orchard has sharply increased since 2000, reaching 446 ha nationwide; Gyeongnam province was most severely damaged, followed by Gyeongbuk and Jeonnam provinces. Most of the farmers answered that they sprayed insecticides and removed the damaged leaves to control P. diospyrosi. The overwintered adults were observed in the damaged-rolled leaves from mid May and the 1st generation adults from early-mid June. No thrips were observed in the damaged leaves after mid July. Yellow sticky trap data showed that peak adults catch of the overwintered generation was mid May, and that of the 1st generation was mid-late June in Gimhae and late June in Jinju. Sticky traps set at orchard-pine forest border caught significantly more number of the 1st generation adults than those at the orchard center, even though timing of peak catches was not different between the two sites. There was a tendency of more catches on the side of sticky trap facing pine forest than the other side facing orchard center, even though the catches on both sides showed no statistical difference.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.6
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• pp.27-37
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• 2021

Conversion of rice paddy field to upland has been accelerated as the central government incentivizes more profitable upland crop cultivation. The objective of this study was to investigate the current status and conversion trend from paddy to upland for the reservoir irrigation districts. Total 605 of reservoir irrigation districts whose beneficiary area is greater than 200 ha were selected for paddy-to-upland conversion analysis using the land cover maps provided by the EGIS of the Ministry of Environment. The land cover data of 2019 was used to analyze up-to-date upland conversion status and its correlation with city proximity, while land cover change between 2007 and 2019 was used for paddy-to-upland conversion trend analysis. Overall 14.8% of the entire study reservoir irrigation area was converted to upland cultivation including greenhouse and orchard areas. Approximately the portion of paddy area was reduced by 17.8% on average, while upland area was increased by 4.9% over the 12 years from 2007 to 2019. This conversion from paddy to upland cultivation was more pronounced in the Gyoenggi and Gyeongsang regions compared to other the Jeolla and Chungcheong provinces. The increase of upland area was also more notable in proximity of the major city. This study findings may assist to identify some hot reservoir districts of the rapid conversion to upland cultivation and thus plan to transition toward upland irrigation system.

• Journal of Agricultural Extension & Community Development
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• v.3 no.1
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• pp.43-54
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• 1996

Citrus farming become one of highly potent area for the farmer s income in the Asia region. Because of its favorable taste and distinctive aroma, attractive color, and nutritional values, market demand has increased steadily along with the income increases in the region. However, realization of the potent have been constrained due to poor orchard management, frequent occurrences of pest and diseases, and a high cost in production besides of the market failures. Cutting down of production cost should be an operational goal to obtain mope profit where marketing structure has yet been underdeveloped. The objective of this study was to provide a comparative information to those program efforts of searching comparative advantage in production. For the three countries, reduction of labor cost by reduction of chemical application frequency was recommended while pursuing further mechanization in those operation such as in pruning, harvesting and pest control. Adoption of the IPM (integrated pest management) will be useful to reduce the number of spraying chemicals with changed knowledge and attitude of the farmers.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.165-168
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• 2011

An organic apple (Malus ${\times}$ domestics Borkh.) orchard was established to study the interaction effects of ground cover management systems (GMS) and nutrient sources (NS) on soil and tree nutrient status and tree growth. Trees received one of four GMS: 1) green compost (GC), 2) wood chips (WC), 3) shredded paper (SP), and 4) mow-and-blow (MB). Across all GMS, one of three NS was applied: A) a commercial organic fertilizer (CF), B) poultry litter (PL), and C) control (NF). Overall, GMS had greater effects on the variables than did NS. GC mulch supplied greater nutrients, followed by WC, SP, and MB mulches. SP trees had lower foliar [N] in the first two years than the GC and WC trees. GC-and WC-treated trees had larger trunk cross sectional area than the SP and MB trees.

• Journal of Environmental Health Sciences
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• v.26 no.2
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• pp.70-79
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• 2000

This study was done for the purpose of investigating the status of the use and perceptions of pesticides among the farmers who spray them in person. And it was also done to provide the basic statistics for the Agricultural Health Policy and study. Over the part of agricultural area in Kyungju and Ulsan City, Korea, from July to September 1999, 1032 questionnaires were distributed and 561 of them were collected and 447 were analysed. Major results of this study are as follows. The proportion of those who have special location for pesticides storage was only 5.3%, and that of those who lock hte storage location was only 13.6%. As to the treatment of bottles after use, most common response was 'burn in home'(47.7%). Most farmers purchase pesticides through 'pesticide store' or 'Agricultural Cooperatives'. The knowledge and Usage of pesticides depends in large part on experiences. The farmers who cultivate orchard spray pesticides more frequently than those cultivate paddy rice mainly. Most common pesticides in use are oganophosphates and carbamates. And also the pesticides that contains so-called 'Environmental Hormone' are used. The perception about the hazards of pesticides is rather superficial and insufficient. 'Herbicide(Gramoxon·Paraco)'(38%) is accepted as the most hazardous by farmers.

• Journal of the Korean association of regional geographers
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• v.11 no.4
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• pp.453-462
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• 2005

The study deals with surface erosion patterns due to the development of cropland toward hillslope and hilltop in the Oncheon-gun, pyeongbuk province and Nampo city of west coast area in the North Korea, using Quick Bird satellite images with 60cm resolution. In North Korea, for national economic difficult after 1980 year, newly developed croplands have been along the gentle hillslope, in which it is possible for individual man power different from the tideland which needs large scaled man-power and equipment. The new croplands are named Darakbat(terraced farm with embankment) and Bitalbat(titled farm developed on the original hill slope), neighboring with orchard and grouped settlement in lower valley. For supplying agricultural water, irrigation ditches and temporal crop storages have been constructed, connecting Darakbat, Bitalbat and orchard. These cropland developments have caused surface erosion composed of 3 types such as pit, linear and headward erosion, together with rill and gully. Owing to poor management of cropland and irrigation system, topsoil erosion and, collapse and sedimentation of ditch and pool, caused the decrease of agricultural productivity. These analysis using Quick Bird images can suggest original raw data about geographical facts on North Korea agriculture and help to recover their agricultural system and plan future national unified land.