• Korean Journal of Medicinal Crop Science
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• v.5 no.2
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• pp.162-166
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• 1997

Variations in growth and yield of adlay(Coix lachyma-jobi var. ma-yuen Stapf) was monitored in farmer's fields in Yunchon, the main producing area in Korea, where the field condition showed difference in topograyphy, crop rotation, and ridge shape. Rotation cropping increased remankably stem length, and number of effective tillers, reduced the occurrence of leaf blight and crop damage by the disease, and in addition showed positive effect to repress the occurrence of stem-borerin upland field. Stem length was greater in upland field than in paddy field and this result seemed to be related to lodging degree. The even field with crop rotation system showed the highest seed yield and followed by hillside field and paddy field resulted the lowest yield.

• Korean Journal of Organic Agriculture
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• v.6 no.2
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• pp.127-140
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• 1998

Organic farming excludes any use of the herbicide. The present paper reviews what can be done for effective weed control with existing weed control technology by farmers crop-ping paddy rice, field crops, vegetables, and fruit trees. If condition of the crop-land-al-lows diversified rotational use of the paddy land as paddy and upland field would minimize weed problem. Practising this is limited in acreage due to extremely limited governmental investment to the land for the purpose. Secondly, rotation of crops in the upland field breaking life cycles of various weeds adapted to each crop should reduce the weed problem. This is also limited as only a few crops are making the farmer profitable. In addition climate and tolerance of crops to high and low temperature. Monsoon rains and poor drainage restrict the freedom of choice. For any crop land year-round multiple cropping in denser planting shall lessen the weed problem, this multiple cropping practiced by 1960s has been abandoned due to laborshortage and increased production cost. Deep flooding the rice is impractical at present in Korean. Mulching crop with transparent, black , or combinated polyethylene sheet, hs been in-creasingly used. Progresses in development and use of mulch with allelopathic crop residues. inexpensive paper mulch, allelopathic crop residues, inexpensive paper mulch, allelopathic crop cultivar development, recently developed ex-perimental weeding machinaries, flamers, microbial herbicides, biological control organisms, soil sterilization techniques have been critically reviewed for their adoption into existing in-tegrated weeding system. Unfortunately, information on cost-benifit, and labor-benefit, for the various methods above mentioned are lacking. Urgent need for the research on rational weeding in organic farming, and herbicide low-input farming is emphasized.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.1
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• pp.89-97
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• 2012

Reduction of greenhouse gas (GHG) emissions from upland crop field as well as paddy field is being required, but little information on GHG emissions according to cultivation practices in upland field is available. Soil GHG emissions during the growing season were investigated in the field of three decades rotation and tillage treatments which were consisted of plow, chiesl tillage and no tillage in west central Indiana, USA in 2006. Seasonal cumulative $CO_2$ emissions were not different among treatments. $CH_4$ emission increased a little in plow tillage during early soybean growing season. Most of $N_2O$ emission occurred during early corn growing season after N-fertilizer application from mid June to mid July, and was significantly affected by tillage practices in which seasonal cumulative $N_2O$ emission was significantly higher under chisel tillage. $N_2O$ emission under no-tillage was lower about 64% and 39% than that under chisel tillage and plow tillage, respectively. No-tillage practice with rotation of corn and soybean seems to be promising in point of less GHG emission and less labor for cultivation without grain yield reduction.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.312-316
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• 1993

This experiment was conducted to increase the utility of paddy field in southern part of Korea. Six cropping patterns were tested 4 times with a cycle of two years from 1985 to 1992. The variation of yield, gross profit and income among years were evaluated. The variation of yield among years in red pepper, garlic and chinese cabbage was higher than that of cucumber, sweet corn and potato in tested crops. The income was higher in chinese cabbage, garlic and red pepper, and the variation of income among years was lower in peanut and chinese cabbage than that of other crops. The income in cucumber-chinese cabbage-green pea-rice pattern and sesamegarlic-rice pattern was higher than the other cropping patterns, but the variance of income among years in the cropping pattern of cucumber-chinese cabbage-green pea-rice was the highest among the tested cropping patterns.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.4
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• pp.334-341
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• 1992

The effects of the various pattern of paddy-upland switching system on rice yield and the nutrient absorption characteristics were examined in the paddy field of Seokcheon silty soil for three years from 1989 to 1991. The obtained results of the two years from 1990 to 1991 are as follows : 1. Rice grain yields were high in the order of potato-cabbage>soybean>continuous paddy plot for the second and third year. Among the rice yield components the numbers of grains per panicle and the rate of ripening grain exerted the yield increase. 2. The contents and absorption amounts of nutrient in harvested straw plant increased with the incease of rice yields during the second and third year(1990~1991). The amounts of all nutrient absorption increased with the increased level of nitrogen fertilization at the third year(1991). 3. The periodical change of leaf green color was responded well with the content of ammonia concentration of soil solution.

• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.423-430
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• 2001

The purpose of this study is to develop high-speed rotary tillage system for a power tiller by improving the rotary blade and the power train of transmission. Mechanical structure of gear train of rotary drive of conventional power tiller was simplified so that power can be transmitted directly from second shaft to tilling speed change shaft by rotating freely the transfer gear which changes the direction of rotation of shafts using needle bearing installed into middle shaft. A new gear train suitable for the single-edged rotary blade and high-speed rotary drive was developed with the rotational speed of rotary shaft faster than 7.5% at 1st-speed and 1.4% at 2nd-speed the one of conventional system by changing the numbers of teeth of gears of middle shaft, tilling speed change shaft and PTO shaft. Using the developed gear train for high-speed rotary drive, field tests were performed to compare tillage performances by the developed single-edged blade and by the conventional double-edged blade. The results showed that the performances by the single-edged blade compared with the one by the double-edged blade was improved about 18% in field capacity, about 34% in fuel consumption, and 9.4% in soil crushing ratio. Therefore, it may be concluded that tillage performance by the single-edged blade was improved compared to the one by the conventional blade. Evaluation of the developed system consisting of single-edged blade and gear train for high-speed rotary drive in field revealed that tillage performance of the developed system was similar to the one of field test conducted using the system consisting of single-edged blade and gear train for rotary drive of conventional power tiller However, considering the higher cone index of the upland field where evaluation was carried out compare to the one of the ordinary paddy field, it may be concluded that tillage performance of the developed rotary tilling system better than the one of conventional system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.370-374
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• 2007

This study was carried out to investigate the soil chemical and physical properties by annul variation and yield properties according to cropping rotation system of paddy field which was cultivated rice and soybean of each 1 year by turns, each 2 year by turns, 1 year of rice and 3 years of soybean and 4 years of soybean continuously. This study was conducted for 3 years from 2002 to 2004 in National Institute of Crop Science(NISC), Korea. Study was controlled by Shinpaldal 2 of midmatured species, sow a field with soybean by $60{\times}15cm$ in 27 May. Chemical fertilizer was spread in the field by N 3.0 kg, $P_2O_5 $ 3.0 kg, $K_2O$ 3.4 kg per 10a. This experiment was carried for increase the degree of self sufficiency of soybean from detect the better cropping system in paddy field. The results of the study were as follows; Soil prosity was increased 17.4% in each one year rotation and 21.8% in the sector of cultivated soybean for four years. Results was indicated that $5{\sim}9cm$ of stem length, $0.5{\sim}1.0ea$ of branch number and $3.5{\sim}7.0$ of SPAD value was decreased in the sector of cultivated soybean for $3{\sim}4$ years compared to $1{\sim}2$ year cultivated sector. The soybean yield was reduced 12.9%(222 kg/10a) in the 2 year cultivated sector and 21%(201 kg/10a) in the 3 year cultivated sector compare with paddy-upland switching cultivation(255 kg/10a). Root nodule weight and number was tend to decrease according to the increasing duration of cultivated soybean.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.315-315
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• 2017

In Japan, more than 80 % of soybean growing area is converted fields and excess water is one of the major problems in soybean production. For example, recent study (Yoshifuji et al., 2016) suggested that in the fields of shallow groundwater level (GWL) (< 1m depth), rising GWL even in a short period (e.g. 1 day) causes inhibition of soybean growth. Thus it becomes more and more important to predict GWL and soil moisture in detail. In addition to conventional surface drainage and underdrain, FOEAS (Farm Oriented Enhancing Aquatic System), which is expected to control GWL in fields adequately, has been developed recently. In this study we attempted to predict GWL and soil moisture condition at the converted field with FOEAS in Biwa lake reclamation area, Shiga prefecture, near the center of the main island of Japan. Two dimensional HYDRUS model (Simuinek et al., 1999) based on common Richards' equation, was used for the calculation of soil water movement. The calculation domain was considered to be 10 and 5 meter in horizontal and vertical direction, respectively, with two layers, i.e. 20cm-thick of plowed layer and underlying subsoil layer. The center of main underdrain (10 cm in diameter) was assumed to be 5 meter from the both ends of the domain and 10-60cm depth from the surface in accordance with the field experiment. The hydraulic parameters of the soil was estimated with the digital soil map in "Soil information web viewer" and Agricultural soil-profile physical properties database, Japan (SolphyJ) (Kato and Nishimura, 2016). Hourly rainfall depth and daily potential evapo-transpiration rate data were given as the upper boundary condition (B.C.). For the bottom B.C., constant upward flux, which meant the inflow flux to the field from outside, was given. Seepage face condition was employed for the surrounding of the underdrain. Initial condition was employed as GWL=60cm. Then we compared the simulated and observed results of volumetric water content at depth of 15cm and GWL. While the model described the variation of GWL well, it tended to overestimate the soil moisture through the growing period. Judging from the field condition, and observed data of soil moisture and GWL, consideration of soil structure (e.g. cracks and clods) in determination of soil hydraulic parameters at the plowed layer may improve the simulation results of soil moisture.

• Korean Journal of Weed Science
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• v.31 no.1
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• pp.41-48
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• 2011

This survey of weed population by different soil moisture with paddy-upland rotation was conducted to investigate information on weed flora and its ecology between two years. Weed species were assessed in April : 2009, 2010. Soil samples were taken from each study plot to assess the impact soil moisture on the occurrence and abundance of dominance weed species. Soil water of poorly drained field ranged from 10.2~18.2% more than 11.8~14.3% of somewhat poorly drained field. Weeds of fields composed of 19 species belonging to 12 families. Among 12 families, 6 weed species belonged to Compositae (31.6%) were the biggest family, Cruciferae were 2 species (10.5%), and Rubiaceae were 2 species (10.5%), respectively. Youngia japonica had the highest summed dominance ratio(SDR) (97.0%) and followed by Conyza canadensis (92.1%), Galium spurium (35.3%) and Hemistepta lyrata (28.4%) of somewhat poorly drainage in 2009. Artemisia princeps the highest SDR (100%) and followed by Stellaria alsine(55.2%), Y. japonica (38.3%) and Nasturtium officinale (28.5%) of poorly drainage in 2009. And, Stellaria alsine had the highest SDR (86.8%) and followed by Alopecurus aequalis (77.7%), Astragalus sinicus (68.7%) and Y. japonica (46.3%) of somewhat poorly drainage in 2010. S. alsine the highest SDR (93.7%) and followed by A. aequalis (78.6%), Nasturtium officinale (31.3%) and Y. japonica (30.4%) of poorly drainage in 2010. Simpson's index was calculated to 0.12~0.23, which showed that weed occurrence with different soil moisture in paddy-upland rotation and between years was various. Similarity coefficient between years was 43.0% (2009) and 74.2% (2010), which indicate a low diversity because of the moisture in the agro-ecosystem.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.2
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• pp.217-223
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• 2015

This study was conducted to serve as a basis for establishing a stable production of proso millet on the rotational paddy-upland field by looking out the physicochemical and moisture characteristics of soil and the growth characteristics of proso millet by ridge width. Plant height showed Manhongchal was the smallest 71.3 cm in 240 cm wide of ridge in the first year, Ibeakchal was the highest 69.7 cm in 60 cm wide in the second year, Hwanggeumchal was the highest 72.8 cm in 60 cm wide in the first year. The retention time of the excess water in the soil during cultivation was extended wider the width of ridge. The variation width of the water content was higher by the wider the width of ridge. Yield components showed the longest ear length were 35.1 cm of Manhongchal, 34.8 cm of Ibeakchal in 60 cm wide of ridge in the first year. As the width of ridge extended, ear weight of all variety increased. 1,000 seed weight of the 60 cm wide of ridge was Manhongchal 6.8%, Ibeakchal 46.2% heavier than the 240 cm wide of ridge. Yield showed Manhongchal 221, Ibeakchal 223, Hwanggeumchal $225kg{\cdot}10a^{-1}$ in 60 cm wide of ridge in the first year. The similar pattern of amount showed Manhongchal 278, Ibeakchal 221, Hwanggeumchal $200kg{\cdot}10a^{-1}$ in 60 cm wide of ridge in the second year. This showed Manhongchal 103%, Ibeakchal 119%, Hwanggeumchal 85.2% was more than the 240 cm wide of ridge.