• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.1
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• pp.48-52
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• 2006

Naturally occurring soybean isoflavones are known to be influenced by various genetic and environmental conditions. Growth, yield, and isoflavone content were determined in four different cultivars of soybean grown under drained paddy and upland fields. Most of growth characteristics and yield components of four different soybean cultivars harvested in drained paddy field were greater than those in upland field, regardless of cultivar. By means of high performance liquid chromatography, total daidzein and genistein contents of soybean in drained paddy field were increased up to 40 and 35%, respectively, compared with those in drained paddy field. Besides isoflavone contents, the growth and yield of soybean were significantly affected by cultivar and field conditions, indicating the necessity of genetic program for soybean cultivars appropriate to drained paddy field conditions. In conclusion, converting paddy field into upland may effectively improve soybean cropping system, especially in terms of isoflavone increment under paddy field conditions.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.1
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• pp.50-55
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• 2017

In attempt to avoid crop damage through wild bird's picking, this study was designed with aim to evaluate several pre-sowing soybean seed coatings for optimum yield in corn-soybean mixed forage. It was investigated under four cropping treatments, viz. 1) corn sole, 2) corn mixed with soybean without any coating, 3) corn with iron coated soybean and 4) corn with thiram coated soybean. Each treatment had three replicates and corn sole was control treatment. Pioneer (P1184) and crossbred ($PI483463{\times}Hutcheson$) seeds were used for corn and soybean, respectively. The trial was conducted under randomized block design from $5^{th}$ June to $23^{rd}$ September, 2015. Data were an alyzed through ANOVA technique using SAS9.1.3 software. Results depicted that survivability of soybean against wild birds damage was found better (p<0.05) in thiram coating which was higher than iron coating and control treatment but later on thiram coating had adverse effects on subsequent growth of soybean plants. Corn stalk height was decreased (p<0.05) in thiram coating, whereas corn ear height was reduced in iron coating treatment. Iron coating enhanced (p<0.05) height of soybean plant (p<0.05) better than that of thiram coating. Soybean seed coatings didn't influence dry matter yield and nutritive value in terms of total digestible nutrients yield in corn soybean mixed forage. Conclusively, although presowing thiram coating enhanced survivability of soybean plants against wild bird damage but had adverse effects on its subsequent growth. However, soybean seed coatings didn't influence yield and nutritive value of corn soybean intercropping forage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.2
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• pp.108-115
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• 2017

The aim of this study was to evaluate different herbicides in corn-soybean intercropping for optimum growth, yield and nutritive value of forage under Korean environment conditions. Herbicidal treatments were randomly applied over five plots, viz. (1) Control treatment: no herbicide; (2) Alachlor; (3) Simazine; (4) Pendimethalin and (5) Mixture of alachlor and simazine herbicides in RCBD have three replications. Results depicted that treated herbicides exhibited significant effect over control of weeds. Simazine herbicide alone or mixed with alachlor had adverse effects on soybean but enhanced (p<0.05) corn production in terms of survivability, dry matter and digestible nutrients yield. Corn-soybean coupling and total dry matter yield were greater (p<0.05) in pendimethalin. Simazine-alachlor mixture reduced (p<0.05) soybean height. Conclusively, simazine could not be suitable for corn soybean intercropping because of having an adverse effect on soybean component. Pendimethalin could maintain growth and yield of corn and soybean both components. Effect of alachlor was comparable to that of pendimethalin.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.4
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• pp.368-372
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• 1999

The practicality of utilizing chitosan as a natural antimicrobial compound to reduce soybean sprout rot was tested. Domestic and imported soybean seeds were soaked for 6 hours in solutions containing different levels of chitosan and acetic acid (glacial), and cultured at $25^{\circ}C$ for 6 days. In case of domestic seeds, soaking with 1,000ppm chitosan increased germination percentage, hypocotyl thickness, total length, and fresh weight of sprouts by 4%, 5%, 2%, and 1%, respectively. The total sprout yield was increased by chitosan in a concentration-dependent manner in that 1,000ppm chitosan resulted in 8% increment of total yield (7.47kg sprouts/kg seed). Chitosan significantly reduced sprout rot percentage to 7.0% compared to control (13.8%), and consequently enhanced marketable sprout yield by 39%. Compared to domestic seeds, the imported soybean seeds exhibited very low germination percentage regardless of chitosan treatments. Chitosan, nevertheless, consistently induced yield increment and rot decrement in imported soybean sprouts. Although 100ppm acetic acid was effective in reducing sprout rot percentage down to 11.8%, its yield-increasing effects were not as prominent as chitosan. In conclusion, soaking soybean seeds with chitosan seems to be a practical method to enhance the efficiency of soybean sprout production.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.367-372
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• 1997

Excessive water stress is one of major limiting factors affecting soybean yield, especially when soybean is grown in converted upland from paddy field. The present study was undertaken to know the genotypic variation in yield response of soybean to different environments in combination with soil texture and underground water table depth. Eight recommended soybean varieties in Korea and two supernodulating soybean mutants introduced from USA were planted in the lysimeter which was filled with two different soil types(sandy loam and clay loam). Of three underground water table depths(10, 30, and 50 cm) during whole growth stage, the lowest 10 cm was included to create excessive water stress. Yield was significantly different according to the underground water table depth and soybean genotypes, whereas soil type did not affect yield. There were significant interaction effects of soybean yield among soil type, soybean genotype, and underground water table depth. Yield of nts 1116 showed the highest across environments. Based on the regression analysis, the most stable variety was Sobaeknamulkong(bi=1.09). Jangsukong was fairly stable and high in yield, when compared to other soybean genotypes. However, nts 1116 was the most desirable ($D_i=228$) mainly due to the highest yield rather than the greater stability over environments. Multiple regression analysis revealed that shoot dry weight and nodule number were major factors affecting yield in the combined data over three water table depths and two soil types.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.2
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• pp.113-118
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• 1989

This experiment was carried out to compare chemical composition, TDN yield of corn-soybean intercropping and corn monocropping forage plants at different harvesting time and obtained the following results. 1. In both cropping systems, the content of chemical composition of forage were changed same pattern in growing stage. The content of crude protein in corn-soybean intercropping forage at yellow stage increased more than that of corn nonocropping forage, while the crude fat in corn monocropping forage plants increased than that of corn-soybean intercropping forage plants at mature stage. 2. The crude fiber, crude ash, ADF content of forage plants in both cropping system decreased same pattern in growing period, however, NFE content of forage increased with maturity. 3. TDN yield of corn-soybean intercropping and corn monocropping forage plants at yellow stage obtained similar results and TDN yield per 10a in intercropping and monocropping were 1006.lkg and 978.6kg, respectively. 4. Consequently, corn-soybean interaopping system could be increased crude protein yield without decreasing of dry matter yield in comparison with corn monocropping system for corn silage.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.614-621
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• 2012

Although there is a broad dispute over genetically modified foods on safety, the worldwide adoption of transgenic crops is rapidly increasing. The objectives of this study were to identify trends in the effects of transgenic on crop yields and examine the effect of agricultural variables including crop type, biotech trait, tillage system, and yield environment on corn and soybean yield. A meta-analysis from the 34 peer-reviewed scientific literatures was conducted to compare the crop yield between transgenic crops and conventional varieties. Results showed that the yield of transgenic corn and soybean was strongly dependent on growing conditions. Transgenic hybrids had higher yield potential in the low crop yield environments such as high weeds and/or insect infestation, low soil water, and cool temperature conditions, while transgenic crops did not have yield advantages in high yield environments. The results from this study suggest that producers should consider the potential yield environmental conditions and possible yield reductions when producers choose crop hybrids in their fields.

• Korean journal of food and cookery science
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• v.1 no.1
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• pp.1-7
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• 1985

This study was conducted to investigate the effect of fat on gain percent, yield and sensory properties of soybean curd by partial or whole replacement of soybean with defatted soy flour, The results obtained were as follows ; 1. Gain percent and yield of soybean curds were decreased as the fat content of materials decreased. 2. In sensory evaluation, the mean scores for appearance (color and smoothness), texture and acceptability significantly decreased as the ratio of defatted soy flour to soybean increased. However, when the defatted soy flour replaced 20 and 30％ of the soybean, the mean acceptability scores did not differ significantly with whole soybean curd. From the above data, if defatted soy flour will be used for making soybean curds with the aspect of sensory and economic reasons, 25％ level of replacement can be recommended.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.4
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• pp.311-318
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• 2002

Planting date of soybeans [Glycine max (L.) Merr.] is one of production components in cultural systems. The objective of the current study was to identify the components of soybean production and cultural practices encompassing planting dates and cultivars that respond to dry matter accumulation, harvest index and yield components. Three determinate soybean cultivars were planted on May 13 (early), June 3 (mid), and June 24 (late). Planting density was 60$\times$15cm with 2 seeds (222,000 plants per ha). Soybean plants were sampled every 10 days interval from the growth stages of V5 to R8 and separated into leaves including petioles, stems, pods, and seeds. Dry matter accumulations, harvest indices, and yield components were measured. Early planting had taken 55 days from VE to R2 and late planting taken 39 days indicating reduced vegetative growth. Early planting showed higher leaf, stem, pod and seed dry weights than late planting. However, late planting appeared to be higher harvest index and harvesting rate. Vegetative mass including leaf and stem increased to a maximum around R4/R5 and total dry weight increased to a maximum around R5/R6 and then declined slightly at R8. The highest seed yield was obtained with mid planting and no difference was found between early and late plantings. Cultivar differences were found among planting dates on growth characteristics and yield components. The results of this experiment indicated that soybean yield in relation to planting dates examined was mainly associated with harvest index and harvesting rate, and planting date of cultivars would be considered soybean plants to reach the growth stage of R4/R5 after mid August for adequate seed yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.4
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• pp.241-244
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• 2000

This experiment was conducted to evaluate the effect on evapotranspiration and yield of soybean according to different soil water conditions, and to find the optimum time and amount for irrigation in soybean cultivation. The difference between potential evapotranspiration (PET) and maximum evapotranspiration (MET) during growing season of soybean planted in lysimeter was higher during reproductive stage than during vegetative one. The maximum crop coefficient was obtained at beginning seed stage of soybean. Soil water coefficient of irrigation treatment was higher than that of non-irrigation treatment during soybean growth stage in field experiment. Grain yield was highest in lysimeter due to its high water use efficiency and evapotranspiration rate.