• Korean Journal of Soil Science and Fertilizer
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• v.10 no.2
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• pp.93-97
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• 1977

A pot experiment was conducted to find out suitable method in determining the rate of phosphorus application. Soybean was planted under optimum moisture condition. The soils used in this experiment were cultivated and non-cultivated mineral soils, and volcanic ash soils. The results were summarized as follows: 1. Phosphorus adsorption maximum(PAM) was the good parameters to determine phosphorus adsorption capacity of all tested soils. 2. Phosporus adsorption maximum was increased with the content of ammonium acetate extractable aluminum, and the organic matter effects on PAM was considerably high in volcanic ash soils. 3. Requirement of phosphorus for maximum yields were in the range of 30~35% of PAM for tested soils. 4. PAM was considered as a suitable criteria to determine the rate of the phosphorus application and it was also considered to be more attractive than phosphorus absorption coefficient.

• The Plant Pathology Journal
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• v.37 no.1
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• pp.57-71
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• 2021

Rice sheath blight (ShB), caused by Rhizoctonia solani Kühn AG1-IA, is one of the destructive rice diseases worldwide. The aims of this study were to develop biocontrol strategies focusing on field sanitation and foliar application with a biocontrol agent for ShB management. Streptomyces padanus PMS-702 showed a great antagonistic activity against R. solani. Fungichromin produced by S. padanus PMS-702, at 3.07 mg/l inhibited 50% mycelial growth, caused leakage of cytoplasm, and inhibited the formation of infection structures of R. solani. Fungichromin could reach to 802 mg/l when S. padanus PMS-702 was cultured in MACC broth for 6 days. Addition of 0.5% S. padanus PMS-702 broth into soil decreased the survival rate of the pathogen compared to the control. Soil amended with 0.5% S. padanus broth and 0.5% tea seed pomace resulted in the death of R. solani mycelia in the infested rice straws, and the germination of sclerotia was inhibited 21 days after treatment. Greenhouse trials revealed that S. padanus cultured in soybean meal-glucose (SMGC-2) medium after mixing with different surfactants could enhance its efficacy for inhibiting the pathogen. Of six surfactants tested, the addition of 2% tea saponin was the most effective in suppressing the pathogen. S. padanus broth after being fermented in SMGC-2, mixed with 2% tea saponin, diluted 100 fold, and sprayed onto rice plants significantly reduced ShB disease severity. Thus, S. padanus PMS-702 is an effective biocontrol agent. The efficacy of S. padanus PMS-702 for disease control could be improved through formulation.

• Korean Journal of Ecology and Environment
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• v.54 no.2
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• pp.120-124
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• 2021

In order to understand the vegetative role of Glycine soja, we studied the basic physiological characteristics between Glycine soja and Glycine max. For this study, the light intensity (μmol m^-2 s^-1) on leaf surface, leaf temperature (℃), transpiration rate (mmol m^-2 s^-1), photosynthetic rate (μmol m^-2 s^-1), substomatal CO₂ partial pressure (vpm) of Glycine soja and Glycine max were measured, and the quantum yield, photosynthesis rate per substomatal CO₂ partial pressure were calculated. In the results of simple regression analysis, the increasing quantum yield decreases leaf temperature both of Glycine soja and Glycine max and the increasing leaf temperature decreases transpiration rate in case of Glycine soja. However, in case of Glycine max, the increasing leaf temperature decreases substomatal CO₂ partial pressure, photosynthetic rate, and photosynthetic rate per substomatal CO₂ partial pressure as well as transpiration rate. Also, increasing transpiration rate increases substomatal CO₂ partial pressure while decreases photosynthetic rate per substomatal CO₂ partial pressure. Thus, Glycine soja is relatively more easily adaptable to severe environments with low soil nutrients and high light levels. Compared to Glycine max susceptible to water loss due to a water-poor terrestrial habitat, the physiological traits of Glycine soja has a high average transpiration rate and are less susceptible to water loss will act as a factor that limits the habitat according to soil moisture.

• Korean journal of applied entomology
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• v.3
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• pp.21-25
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• 1964

1. Purpose of this experiment is to investigate the influence of wheat scab fungus(Gibberella zeae) remaining in soil or residues of infected plants to the growth of the seedlings of 14 different crops. 2. Susceptibility of these crops to the infection by G. zeae was investigated by planting these crops both to the artificially inoculated soils and naturally infected soils where both serious and light wheat scab epidemic have occurred previously. 3. In artifical inoculation tests, bailey, wheat, rye, soybean, rice, buckwheat, corn, cotton and greenbean has shown susceptible reaction, while indianbean, sesame, sorghum, chinese cabbage and radish has shown resistant reaction. 4. In artificial inoculation tests, there was significant difference in the germination ratio of the susceptible crops between the plants planted in inoculated soils and uninoculated soils with the exception of rice, com and cotton. Preemergence seedling blight was confined only to barley and corn, whereas postemergence seedling blight was confined to rye, wheat, rice buckwheat, barley and corn. la most of the susceptible crops secondary roots were almost rotted and the primary roots were either partially rotted or discolorated in inoculated soil. There was significant difference in the stem length of the plants grown in inoculated soils and uninoculated soils in susceptible crops. 5. No infection by G. zeae was observed when wheat, barley and rye plants were sown to the soils where both serious and light wheat scab epidemic occurred naturally.

• 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 the Korea Organic Resources Recycling Association
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• v.14 no.1
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• pp.160-168
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• 2006

This study was performed to evaluate the effect of the addition of vegetable oils on Fenton treatment of PAHs-contaminated soil. Fenton reaction can be proceeded in the soils contaminated with PHAs only in the presence of $H_2O_2$ because of Fe content in the soil. In this case, optimum $H_2O_2$ concentration was 3%. When 17.5 mM $FeSO_4$(III) was added with 3% $H_2O_2$, the removal rate was increased up to 25%, whereas 19% of PAHs was removed with $H_2O_2$ alone. The addition of 1% of olive oil to the contaminated soil before the Fenton reaction or simultaneously increased the removal rate about 15%, compared to the case of Fenton reaction only. There were no significant differences in the removal rates of PAHs, regardless of different kinds and concentration of oils. (olive oil, soybean oil, and used-vegetable oil). The used-vegetable oils were not different from the new, expensive oils in the removal rate, so their use will be desirable in saving the money. In addition of 1% of olive oil after the reaction of 3% $H_2O_2$ and 2.5 mM $FeSO_4$(III), the removal rates of 3~4 and 5~6 ring compounds were increased 13% and 17%, respectively, compared to the case of Fenton reaction only.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.3
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• pp.187-195
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• 2019

The needs for precise diagnostics and farm management-decision aids have increased to reduce the risk of climate change and environmental stress. Crop simulation models have been widely used to search optimal solutions for effective cultural practices. However, limited knowledge on physiological responses to environmental variation would make it challenging to apply crop simulation models to a wide range of studies. Advanced research facilities would help investigation of plant response to the environment. In the present study, the sunlit controlled environment chambers, known as Korean SPAR (Soil-Plant-Atmosphere-Research) system, was developed by renovating existing SPAR system. The Korean SPAR system controls and monitors major environmental variables including atmospheric carbon dioxide concentration, temperature and soil moisture. Furthermore, plants are allowed to grow under natural sunlight. Key physiological and physical data such as canopy photosynthesis and respiration, canopy water and nutrient use over the whole growth period are also collected automatically. As a case study, it was shown that the Korean SPAR system would be useful for collection of data needed for understanding the growth and developmental processes of a crop, e.g., soybean. In addition, we have demonstrated that the canopy photosynthetic data of the Korean SPAR indicate the precise representation of physiological responses to environment variation. As a result, physical and physiological data obtained from the Korean SPAR are expected to be useful for development of an advanced crop simulation model minimizing errors and confounding factors that usually occur in field experiments.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.325-331
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• 2012

The dual inoculation response of soybean with rhizobium and mycorrhiza was examined in pot vermiculite and field soils. In order to select a symbiotically compatible mycorrhiza with Bradyrhizobium japonicum, a highly germinating spore among 60 strains from 32 upland soils in southern part of Korea was obtained in Acaulospora sp., Gigaspora sp. and Glomus sp., respectively. As a result of dual inoculation of Glycin max cv. Dajangkong and Eunhakong both with $1{\times}10^8$cells of B. japonicum YCK 213 and 10 spores of each mycorrhiza in vermiculite pot, only Glomus sp. treatment together with the rhizobium showed significant increase ($P{\leqq}0.05$) both in shoot dry wt and nodule mass of not Eunhakong but Dajangkong. In red-yellow soils with pH 5.2($1:5H_2O$) and 203 mg of Lancaster P per kg of soil, in which $10^3$ cells of B. japonicum and $10{\pm}0.2$ spores of mycorrhizae per gram of soil were naturalized, grain yield of G. max cv. Dajangkong was increased to 3.9% by dual inoculation both of $4.8{\times}10^6$cells of B. japonicum and 10 spores of mycorrhizae per two seeds under condition applied with 30 kg $P_2O_5$ and 34 kg $K_2O$ per hectare compared to conventionally fertilized plot (2.75 MT $ha^{-1}$) added with 30 kg N $ha^{-1}$. However, there was not significant.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.804-811
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• 2010

The lower portion of sloping paddy fields normally contains excessive moisture and the higher water table caused by the inflow of ground water from the upper part of the field resulting in non-uniform water content distribution. Four drainage methods namely Open Ditch, Vinyl Barrier, Pipe Drainage and Tube Bundle for multiple land use were installed within 1-m position from the lower edge of the upper embankment of sloping alluvial paddy fields. Knowledge of the spatial variability of soil water properties is of primary importance for management of agricultural lands. This study was conducted to evaluate the effect of drainage in the soil on spatial variability of soil water content using the geostatistical analysis. The soil water content was collected by a TDR (Time Domain Reflectometry) sensor after the installation of subsurface drainage on regular square grid of 80 m at 20 m paddy field located at Oesan-ri, Buk-myeon, Changwon-si in alluvial slopping paddy fields ($35^{\circ}22^{\prime}$ N, $128^{\circ}35^{\prime}$). In order to obtain the most accurate field information, the sampling grid was divided 3 m by 3 m unit mesh by four drainage types. The results showed that spatial variance of soil water content by subsurface drainage was reduced, though yield of soybean showed the same trends. Value of "sill" of soil water content with semivariogram was 9.7 in Pipe Drainage, 86.2 in Open Ditch, and 66.8 in Vinyl Barrier and 15.7 in Tube Bundle.

• Korean Journal of Environmental Agriculture
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• v.13 no.3
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• pp.346-358
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• 1994

In this paper, the current knowledge on the formation of acid rain and its effect on vegetation are reviewed. The pollutants which were emitted into the air are oxidized by photochemical reaction and affect the vegetation by dry and wet deposition. Acid rain at pH 4.0 affected sensitive plants and when it was below pH 3.0, visible symptoms developed in most of the crops. The acid rain treatment at pH 2.0 decreased dry weight, leaf area and chlorophyll contents in soybean but it increased rate of photosynthesis and respiration rate. Rain treatment at pH 2.8 increased ethylene production, but it’s not a suitable indicator of sensitivity to acid rain. At pH 2.0 treatment, the contents of soluble Mn and Al were increased but the cultivated soil pH at upper layer(0-5cm) was significantly decreased. The pertubation of glandular trichome which is existed along the vein was developed at all treatment except the control(pH 6.0) and non-treatment. Histological pertubation of spiked trichome and disintegration of chloroplast were developed only on the leaves of sesame treated with SAR(simulated acid rain) of pH 2.0.