• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.247-252
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• 2005

Soil pH is an intensity factor of releasing hydrogen ion which is buffered by aluminum. It depends on pH buffer capacity of Al whether soil pH is governed directly by cations or not. A study was conducted to elucidate the pattern of pH changes by soil EC. Fertilizer and three kinds of organic manures composed of cow and pig and fowl dropping and one kind of rice straw compost were added independently into upland sandy loam soil. This treated soils and four upland soils under plastic film house having different levels in electrical conductivity (EC) were incubated with field capacity at $30^{\circ}C$ for 5, 10, 20 and 40 days. Soil pH varied directly as the cations contained in organic materials according to degree of saturating pH buffer capacity (pBC) of sandy loam soil. pH of the soils under plastic film house was lowered by soil EC due to governing by overplus of cation beyond pBC.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.400-406
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• 1998

To investigate the effect of simulated acid rain on the change in soil chemical properties, simulated acid rain of different pH was applied to the three soils of different texture. Simulated acid rain of pH 4.0 and 6.0 did not greatly change the soil pH, while simulated acid rain of pH 2.0 decreased greatly the soil pH. Decrease in soil pH were in the order of sandy loam > loam > clay loam, while increase in exchangeable acidity was in the order of clay loam > loam > sandy loam. Amount of nutrients leached downward due to the penetration of simulated acid rain into the soil was in the order of Ca > K > Mg. Exchangeable Al was not detected when soil acidity dropped to pH 5 and exchangeable acidity increased within a range of CEC. A total 1200mm of simulated acid rain(pH 3.0) can load $12kg\;ha^{-1}$ of $H^+$ ion, $128kg\;ha^{-1}$ of sulfur, $56kg\;ha^{-1}$ of nitrogen. The acidity of simulated acid rain pH 3.0 can be neutralized by addition of $444kg\;ha^{-1}$ of slaked lime. The amount of leached bases were equivalent to 923, 1731 and $1608kg{\cdot}ha^{-1}$ in sandy loam, loam and clay loam soil respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.2
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• pp.95-101
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• 1991

The results of relationships between colloidal stability and soil pH on three Hawaii's volcanic ash soils developed under the three different rainfall conditions can be summarized as follows: 1. The Hilo soil only revealed the increase of colloidal stability by becoming for from Z.P.C point to either side of pH. 2. Hilo and Kawaihae soils, however, showed the increase of colloidal stability only in the higher pH range than their Z.P.C. 3. $P_2O_5$ drying procers decreased colloidal stability kof these soils because of so called irreversible drying characteristics of amorphous materials and the decrement was in order of: Akaka>Hilo>Kawaihae expressing positive correlation with content of amorphous materials in them. 4. The difference of colloidal stability curves among three soils can easily be interpreted by DLVO theory considering 0.1N-HCl amount added to decrease their soil pH, respectively. The addition of large amount of 0.1N-HCl into Akaka and Kawaihae soils did not effectively develop the positive charge but resulted in the shrink of diffuse double layer thickness inducing large attraction forces among soil particles.

• Korean Journal of Environmental Agriculture
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• v.17 no.4
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• pp.362-367
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• 1998

To investigate the effects of simulated acid rain(SAR) on the downward movement of mineral nutrients, SARs of different pH were applied to the soil. SAR of pH 2.0 decreased the soil pH greatly, while SAR of pH 4.0 and 6.0 did not change the soil pH to compare to that of SAR of pH 2.0. Decrease in soil pH was in the order of sandy loam > loam > clay loam. The amoumt of leached exchangeable and soluble bases from the soil due to the penetration of SAR was in the order of Ca >Mg > K. After application of 1200mm SAR of pH 2.0 in to the soil downward mean movements of the exchangeable and soluble bases was in the order of Mg > Ca > K in sandy loam and loam soil and Ca > Mg > K in clay loam soil. Downward movements of the those bases under pH 4.0 into the soil was in the order of Mg > K > Ca in sandy loam and clay loam, and K > Mg > Ca in loam soil. Available phosphorus moved slightly downward with increasing acidity of the SAR.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.4
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• pp.483-492
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• 1986

To find out the responses of plant growth, nodulation, and yield of soybean and their varietal differences to different soil pH, 16 soybean cultivars were examined under three different levels of soil pH. In general, as the soil pH decreased, plant growth, nodulation, yield and yield component and protein con-tents of grains were decreased in most of cultivars studied. But there were significant varietal differences in the responses of the characters investigated to soil pH. Jangbaegkong was evaluated as the most tolerant cultivar to acid soil, and Ulsan, Bongeui, Hwanggeumkong, and LC7852 were also relatively torelant to acid soil. There were significant correlation between soil pH and grain yield in 7 cultivars among 16, but were not in other cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.1
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• pp.12-22
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• 1988

The effects of pH and Aluminum treatment on the seedling growth were examined with 11 cultivar under three levels of pH in nutri-culture.. Growth and yield responses of soil pH and nitrogen fertilization were also studied with five cultivars under 3 levels of soil pH and 3 levels of nitrogen application in the field experiment. The effect of pH on the seedling growth was not significant, but Aluminum treatment significantly decreased the seedling growth in nutri-culture except Dusan ＃12. Chlorophyll contents of leaves, dry weight of plants, culm length, spike numbers per unit area, grain numbers per spike, grain weight, and yield were decreased as the decrease of soil pH, and thus highly significant correlation between soil pH during barley growth and yield was observed in all cultivars examined. The stable cultivars to different soil pH with high yield was not found although the decreases of yield were different with cultivars. The increase of nitrogen fertilization significantly increased the nitrogen and chlorophyll contents of leaves, and dry weight of plants, while showed a little effects on the culm length, spike number per unit area, grain number per spike, grain weight and yield. The yield was significantly correlated with culm length, dry weight of plants, grain numbers per spike and 1000 grain weight at each pH levels.

• Journal of Ginseng Research
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• v.25 no.1
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• pp.53-58
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• 2001

To clarify a significant difference between red-colored phenomena (RCP) and microbes isolated from rhizosphere soil of healthy ginseng (HES) and red-colored ginseng (RCS), we have examined growth and cellulase activities of the microbes according to pH variation and iron status. The soil microbes could not grow at pH 3.0 on the YEB medium. The growth of bacterium isolated from RCG at pH from 5.0 to 9.0 showed small differences and the growth of bacterium HES was lower than that of others. The growth of bacteria from RCS and surface soil (SUS) at pH 5.0 were also lower than that of pH 7.0 and pH 9.0. However, the bacteria isolated from red-colored ginseng (RCG) and RCS are able to grow on the medium contained 2 mM Fe$\^$3+/ at pH 3.0. Furthermore, the growth of bacterium from RCG increased about two times in the medium contained iron at pH 7.0 compared with minus iron. The cellulase activity of isolated bacteria increased two times in the medium contained 2 mM Fe$\^$3+/ compared with minus iron. The activity of extra-cellular cellulase was higher by one hundred times than that of intracellular level. The cellulase activity of the bacterium from RCS at pH 5.0 was higher by two times than that of pH 7.0. Especially, intracellular activity of the bacterium from RCS on the medium contained 2mM Fe$\^$3+/ increased about six to seven times compared with control (minus iron). Also, extra-cellular activity increased about eleven to twelve times compared with control. These results indicate that the soil microbes seem to be related iron redoxidation by proton extrusion and with cell wall digestion by secreted cellulase.

• Korean Journal of Medicinal Crop Science
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• v.6 no.4
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• pp.239-244
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• 1998

This experiment was to determine the effects of soil pH on crude components and aromatic constituents of Codonopsis lanceolata. Vine length of Codonopsis lanceolata grown at soil pH of 6.5 was longer(299cm) compared to that grown under other soil pHs. Fresh root weight increased at soil pH of 5.5 and 6.5, showing 17.9 and 15.6g per plant, respectively. Contents of crude components such as protein, fat, fiber, and ash decreased as soil became alkalized and crude ash content ranged from 2.99% to 3.85 %, showing a similar response to soil pH. Forty-eight volatile aromatic compounds in the root of Codonopsis lanceolata were identified by GC/MS. Major aromatic compounds were 1-hexanol, cis-3-hexanol, and trans-2-hexanol. In particular, trans-2-hexanol was highest in soil pH of 6.5, attaining the 156.87% area. Essential oil content was also highest at soil pH of 6.5 with 0.007%. As a result, it was considered that the soil pH of 6.5 was most effective for the improvement of essential oil and aromatic constituents in the roots of Condonopsis lanceolata Trautv.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.67-77
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• 1987

To obtain basic information concerning the soybean cultivar differences of physiological and ecological responses to soil pH to select and breed stably higher yielding cultivars, and to improve cultural management of soil differing in pH, the responses of soybean plants in growth, grain yield, nodule formation and its activity, and major chemical compositions of soybean plants were investigated using six cultivars and two levels of soil pH 5 and 7 of the pot and field experimental soil in Suwon, 1985. Acidic soil condition suppressed overall vegetative growth of soybean plants and thereby decreased stem length, number of nodes, leaf area, dry weight of the plants, root activity, nodulation and nodule activity, the content of allantoin nitrogen, total nitrogen, phosphorous, calcium, and magnesium of the plants. Due to the such responses of soybean plants to the acid soil, grain yield also decreased along with less grains per plant. However, the little difference in growth and yield of the cultivar Janbaeglcong in response to soil pH is considered to be a good source of breeding materials tolerant to acidic soil condition. In this regard Bongeui and Oialkong also were relatively stable in the growth and grain yield under the different soil acidity conditions.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.156-156
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• 2003

유럽의 여러나라들의 경우 토양내 중금속의 허용치는 그 사용 목적에 따라 다르게 책정되고 있으며 1999년에 제정된 독일의 새로운 토양보전법에서도 토양의 사용목적별로 중금속 허용치를 달리 정하고 있다. 여기서 중금속 농도를 측정하기 위한 방법으로는 DIN(독일 공업규격)에서 정하고 있는 증류수추출법과 왕수추출법이 채택되고 있다. 그러나 이 2가지 방법들은 토양의 중금속분석에서 가장 큰 factor로 작용하는 것이 pH인데 반하여 pH가 7인 증류수와 pH가 0인 왕수를 사용함으로써 실제환경에 적용하기에는 많은 무리수를 내포하고 있으며 차츰 적당치 못한 것으로 판명되고 있다. 실질적인 중금속의 유해성 여부는 토양에서의 그 중금속의 용해도와 유동성으로 결정되는데 강한 산성비가 내린다고 가정하였을 때 비의 pH가 약 4 정도이고 이 경우 식물 뿌리 부분의 pH는 5 정도가 되므로 pH를 기준으로 할 때 잠재적으로 유동가능한 중금속을 분석하는 데에는 pH 4.5 에서 EDTA 추출이 가장 적당하고 또한 이를 토대로 토양내 중금속 허용치를 정하는 것이 합리적이라고 하겠다. 그러나 EDTA는 pH 4에서 부분적으로 Proton과 결합되어 Metal Chelate로의 능력을 잃게 되고 또한 식물 뿌리의 중금속 흡착을 Simulation할 수 없어 불리한 점이 있다. 또한 EDTA는 분해기간이 길고 인체에 해롭다는 것이 알려지고 있어 점점 사용이 어려워지고 있다. 본 연구에서는 토양에 함유된 유동가능한 중금속농도분석을 보다 적절히 하기 위한 방법으로 EDTA와 같이 Carboxyl기가 결합된 고분자 자성체를 이용해 토양의 중금속을 분석하는 것을 제안하였고 분석을 위한 중금속 추출 시 토양시료와 증류수 그리고 고분자 자성체만을 사용하여 근본적으로 토양에서 유동 가능성이 있는 중금속만을 추출하였다. 분석실험은 토양의 Cd2+ 와 Pb2+를 대상으로 행하여졌으며, 여러 토양에서 추출 분석한 결과를 EDTA분석결과와 비교하였다. 실험결과, 중금속은 매우 신속하게 고분자 자성체와 결합하였고, 그 후 자성체를 외부 자장으로 모은 후 산으로 용해시키고, 결합된 중금속은 Graphite furnace AAS로 분석함으로써 빠르고 효율적으로 분석실험을 수행할 수 있음을 알 수 있었다. 한편, 실험에서 나타난 수치들을 비교 검토한 결과 토양 분석시 sandy soil에서는 자성체를 이용한 분석이 EDTA에 의한 방법보다 더 높은 추출도를 보인 반면, silt 함량이 많은 토양의 경우에서 EDTA분석에서 더 높은 중금속 추출도를 보였다.