• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.356-369
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• 1985

In Korea, inevitable researches for the blast control exactly started from 1927 by the organization of Office of Rural Development with the local extensive outbreak of panicle blast at Jeonlla Buk-Do Province in 1926. At present, the rice blast is still one of the most destructive and widespread diseases in spite of considerable contributions by rice scientists, particularly plant pathologists during last 55 years in Korea. Rice blast control and management are very difficult because of the marked variability in pathogenicity of the blast fungus. From the results obtained through the disease surveys during last 70 years, different 3 prevalence type of blast such as bimodal leaf-blast type, bimodal panicle-blast type and bimodal continual blast type were recognized. In generally speaking, pattern of blast outbreak is said to be characterized by severe outbreak of panicle blast after slight outbreak of leaf blast with discontinuity between leaf and panicle blast. So we have to pay much attention for successful management of panicle blast giving direct influence to rice yield. Main factors induce blast epidemic were pointed out to be breakdown of the disease resistance, nutritional unbalance such as excess application of nitrogen, delay of transplantation and longspell of rain fall by extensive surveys and researches on blast during last 70 years in Korea. The fact some of Japonica varieties such as Kokuryomiyako, Tamanishiki, Ginbozu and Pungok belong to varietal group A had been cultivated with extensive acrage over 30 years in this country should be mentioned by Korean rice scientists. Differences in field resistance between varieties in the same group are detectable and apparently small but sometimes epidemiologically significant differential effects may be found out in case of blast. Much more attention should be payed to accumulate the knowledges on field resistance for successful management of blast. Excess application of nitrogen is more effective to outbreak of panicle blast than that of leaf blast of IR varieties. In comparatively low level application of nitrogen infection rate of panicle blast of IR varieties is considerably high. Low temperature effects on outbreak of blast is very great. It results in remarkable increase of the inoculum potential on the leaf lesions and infection of panicle blast in leaf sheathes of IR varieties during the booting stage. In economic point of view, it is concluded that 5 times sprays of effective fungicides including 3 times before and 2 times after heading is good enough to control blast. We have experienced no one of control measures for blast is superior to all others. The integrated control measures was established as guideline of blast control around 1950 in Korea. This guideline must be helpful for rice growers as long as rice growing continue.

• Journal of Korean Society of Forest Science
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• v.41 no.1
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• pp.7-18
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• 1979

Almonds are one of the oldest sources of food and oil for man as used the ice cream, candy, roast, salting, chocolate, breads, backed, cookies, and flavoring ect. So, we wish to plant Almond in our country at the most parts of mountains. In this purpose we must be find out of both root stock of more compatibility and new techniques of grafting was rather simples as compared with the many steps of machinary involved today. This investigation has been carried out to reveral compatibility and practical controls of environment effectives involved in the occurence of each difference combination results in interspecific grafting of Almonds on the root stock of Prunus mandshurica and Prunus persica as materials during the 9 months period from March to November in 1978. With these selected scions were 4 varieties of Almond employing as the Hal1's hardy, Nonpareil, and Thompson grafted in the polyethylene green house with almost identical provision made for effective controls of automatical supplying to heating and mistsprayers as the $22{\sim}25^{\circ}C$ of temperature and 70~90% humidity. Following results have been obtained. Those environmental controls were more effective and practical to grafting unions and success by means veneer-grafting at the green house. 1. Hall's hardy Almond grafted on the root stock of Prunus persica was more compatibility than Prunus mandshurica. 2. The survival percentages as follows of the 95.33% of Hall's hardy/Prunus persica and 92.66% of Hall's hardy/Prunus mandshurica. And those were no significant between root stock of both species. 3. The 3 varieties of sweet Almond grafted on the root stock of P. mandshurica. And those were no significant between root stock of both species. 4. And the survival percentages as fellows. Thompson 92.66%, Nonpareil 90.66% and Kapareil 89.33% those grafted on the root stock of Prunus persica. 5. And then the survival percentage of interspecific grafts on the root Prunus mandshurica as follows of the materials of Thompson 89.66%, Nonpareil 87%, Kapareil 85%. 6. The analysis of variance were no significant among the interactions between 3 varieties Almond and 2 species of root stock plants. 7. And the growth of interspecific grafts of the high 161cm, diameter 12.3mm and length of roots 21.5cm growth as the Hall's hardy Almond grafted on the root stock of Prunus persica. 8. The root stock plants of Prunus mandshurica more effected to 6~8 days early developed leafing of scions and dark green colour than the Prunus persica. 9. The identical provision of automatic systems was more effective to graft unions and grafting process. 10. The veneer-grafting method at the green house was more effective and practical method for the mass production of Almond grafts.

• Journal of Korean Society of Forest Science
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• v.13 no.1
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• pp.67-78
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• 1971

The measures of contour-terracing with sod has been executed as a major measures for hillside erosion control works for a long time in Korea. It is, however, recognized that pair terracings make a new slope-face having the more steeper degree of slope between the upper and the lower terraces on hillsides and it also does not contribute for establishing the natural vegetation-cover by penetration of pioneer seeds on the slope faces or cut-faces of hillsides. The study was therefore conducted in connection with the above problems on the cut-face having slope of $40^{\circ}$ and 1.6 meter in slope length with clay soils. Plot allocation for the experiment consists of 3 kinds of 3 replica plots having each $1.6m^2$ of slope area, i. e., the control plot with direct seeding on slopes only ($T_1$), the covering plot with the straw-mats after seeding on slopes ($T_2$) and the seeding plot after covering with the straw-mats. ($T_3$). The main results obtained may be summarized as follows : 1. Effects of the straw-mat mulchings on surface soil loss control:-The total amount of soil losses from each treatments are measured as 4,651 gr from $T_1$, 163 gr. from $T_2$ and 2,891 gr. from $T_3$ treatment respectively. (Refer to table No. 2, 3 and 4). In short, it is recognized that effect of $T_2$ treatment is compared as 28.5 times than that of $T_1$ treatment and 17.7 times than that of $T_3$ treatment respectively. Effect of $T_3$ treatment compared with $T_1$ treatment is also such recognizable as 1.6 times in control of surface soil losses on a slope face. 2. Effect of the straw-mat mulchings on soil moisture content on slopes; -Average per cent of surface soil moisture content by treatments show as 21.60 at the $T_1$, 23.04 at the $T_2$ and 22.21 at the $T_3$ treatment respectively and that of subsurface soil moisture content by treatment show as 23.81 at the $T_1$, 26.16 at the $T_2$ and 24.81 at the $T_3$ treatment respectively. The variance of soil moisture content by treatments was highly significant (Refer table No. 7, 8 and 9). 3. Effect of the straw-mat mulchings on vegetation establishment;-Average numbers of germination by treatments are counted as 237 Nos. at the $T_1$, 246 Nos. at the $T_2$ and 262 Nos. at the $T_3$ treatment plots and the vegetation coverage on ground was almost same as about 90% of covers in all treatments. This effect is more or less lower than that of surface soil erosion control. 4. Regarding the effect on surface soil erosion control, the straw-mat mulchings would be effective as a new measures for control of soil erosion on erosion susceptible lands such slope-faced bare-lands as cut-fill faces, mass-movement faces and bare hillsides.

• Journal of Korean Society of Forest Science
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• v.30 no.1
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• pp.8-18
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• 1976

This study was carried out to exploit and utilize the exotic American Sycamore(Platanus occidentalis) grown in Korea as a veneer species for plywood manufacture. At present most parts of veneer Legs used in Korea were depended entirely upon the gonus Shorea woods(lauan logs) imported from Southeast Asia region. To decrease manufacturing cost and save imported lauan veneer logs, the effects on properties affecting to the six types of plywood made from proper veneer constructions composed by domestic American Sycamore and imported lauan veneers were compared and discussed. The study has important meanings for the promotion of plywood manufacture by domestic materials. Important items dealt with this study were dry and wet shear strength, moisture contents, specific gravties, and bending strength. By the results and discussions it may be summarized as follows: 1) In dry shear strength platanus(sycamore) core lauan plywood was shown most excellent strong results, and next orders were all lauan plywood, platanus faced lauan plywood, lauan core platanus plywood, lauan faced platanus plywood, and all platanus plywood. There was no difference between platanus core lauan plywood and all lauan plywood, but the differences between those plywoods and the other types of plywood were recognized. 2) In wet shear strength platanus core lauan plywood was shown excellent result the same as dry strength. The difference between platanus core lauan plywood and the other types of plywood was shown, but among the other types of plywood except platanus core lauan plywood were not recognized. 3) The differences among moisture contents according to the veneer construction were not recognized. 4) The plywood constructed by two or more sheets of lauan veneer was shown lower specific gravities than the plywood constructed by two or more sheets of platanus veneer. It is believed that this tendency due to the original specific gravities of veneer before construction. 5) The differences among specific gravities of lauan core platanus plywood, all platanus plywood and lauan faced platanus plywood were not recognized, and like this analyzed result among platanus core lauan plywood, all lauan plywood and platanus faced lauan plywood were not recognized. Accordingly it is believed that the differences are not shown among the plywood constructed by two or more veneers of same species. 6) In bending strength platanus core lauan plywood was shown most excellent values. Next orders were all lauan plywood, platanus faced lauan plywood and the other types of plywood. The differences among the plywood constructed by two or veneers of lauan were shown, but not shown among the plywood constructed by tow or more veneers of platanus.

• Journal of Korean Society of Forest Science
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• v.77 no.4
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• pp.429-444
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• 1988

Considering the recent trent toward the development of multiple-use of forest trees, investigations for comprehensive information on these young stands of Hinoki cypress are necessary for rational forest management. From this point of view, 83 sample trees were selected and cut down from 23-ear old stands of Hinoki cypress at Changsung-gun, Chonnam-do. Various stem growth factors of felled trees were measured and canonical correlaton analysis, principal component analysis and factor analysis were applied to investigate the stem growth characteristics, relationships among stem growth factors, and to get potential information and comprehensive information. The results are as follows ; Canonical correlation coefficient between stem volume and quality growth factor was 0.9877. Coefficient of canonical variates showed that DBH among diameter growth factors and height among height growth factors had important effects on stem volume. From the analysis of relationship between stem-volume and canonical variates, which were linearly combined DBH with height as one set, DBH had greater influence on volume growth than height. The 1st-2nd principal components here adopted to fit the effective value of 85% from the pincipal component analysis for 12 stem growth factors. The result showed that the 1st-2nd principal component had cumulative contribution rate of 88.10%. The 1st and the 2nd principal components were interpreted as "size factor" and "shape factor", respectively. From summed proportion of the efficient principal component fur each variate, information of variates except crown diameter, clear length and form height explained more than 87%. Two common factors were set by the eigen value obtained from SMC (squared multiple correlation) of diagonal elements of canonical matrix. There were 2 latent factors, $f_1$ and $f_2$. The former way interpreted as nature of diameter growth system. In inherent phenomenon of 12 growth factor, communalities except clear length and crown diameter had great explanatory poorer of 78.62-98.30%. Eighty three sample trees could he classified into 5 stem types as follows ; medium type within a radius of ${\pm}1$ standard deviation of factor scores, uniformity type in diameter and height growth in the 1st quadrant, slim type in the 2nd quadrant, dwarfish type in the 3rd quadrant, and fall-holed type in the 4 th quadrant.

• Journal of Korean Society of Forest Science
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• v.76 no.2
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• pp.109-118
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• 1987

The purpose of this study was to investigate the inhabiting ecology of wild birds using artificial nests in Gyeongnam province. The sort of birds, the utilization of artificial nests by the materials, by the sites and by the forest type, and other inhabiting ecology of birds were investigated from 1984 to 1986. The results obtained were as follows; 1. Wild birds in surveyed areas were classified into 20 families and 35 species. Among them the birds inhabiting the artificial nests were 6 species and those using them most frequently were Parus ater (17.2%), P. major (16.7%) and P. palustris (12.2%). 2. The artificial nests installed on the top and at the toot of the mountain were chiefly utilized by P. ater and P. major, but the artificial nests in park area were mostly used by Passer montanus and Sturnus cineraceus. 3. Sixty-one percent of the artificial nests were utilized by the birds; 45.5% were used for breeding and 15.6% were inhabitation only. 4. When different nest materials and shapes were tested, mixed nests (sawdust and cement) were used most frequently, and C type. (Diamond shape) of wood nests was used more frequently compared with the A (Roof shape) and B (Box shape) types of wood nests. Meanwhile, the birds prefered the 3cm hole size (81.1% of utilization) to 4cm of hole (57.8%) and 5cm of hole (24.4%). 5. The artificial nests constructed in mixed forest were more frequently inhabited (73.3%) by the birds than coniferous forest (68.3%) and broad-leaved forest (63.3%). 6. The period of egg-laying in Parus species was from late April to early May, while Eophona migratoria, Lanius bucephalus, Motacilla alba and Passer montanus laid eggs generally in the middle of May. 7. Parus species, Passer montanus and Motacilla alba laid one egg every day for 5-10days, but Eopphona migratoria laied 4 eggs in 7 days and Lanius bucephalus laid 5 eggs in 4 days. The incubation period of Parus species was 16-18 days, while the others were about 11 to 14 days. 8. Thirteen days after the hatch of Parus major, chicks reached 13.9g of body weight, 72.0mm of wing-length and 20.9mm of tarsus length. P. montanus chicks reached 20.3g of weight, 66.2mm of wing-length and 20.2mm of tarsus length during the same period. 9. Food item of feeding chicks almost consisted of creatures (98.2%) with following composition; 55.2% of insect larvae, 37.2% adult insects, 2.8% of pupae and 2.8% of spiders. Vegetable items were 2% only. Among those creature food items, 95.2% were insect pests to forest.

• Korean Journal of Poultry Science
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• v.35 no.4
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• pp.375-380
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• 2009

This study was conducted to investigate the effect of feeding induced molting on the visceral organs and blood component profile in laying hens and designed to test 400 flocks of 60 week old Leghorn laying hens for 34 weeks. A total of four molting treatment methods by including the molted with customary molting by fasting method (c), feeding single diet of corn (T1), feeding single diet of wheat bran (T2) and feeding single diet of alfalfa meal (T3) were tested, and each treatment was repeated for 5 times, and 20 laying hens were randomly assigned in an cage for each repeat. As the result of the experiment, ovary was $2.03{\sim}6%$ and oviduct was $2.51{\sim}3.47%$ in visceral organs for body weight at pre-molting term, but there was no significant difference. At post-molting, no significant difference was found, ovary was $0.25{\sim}0.41%$, uterus of control, T1, T2 and T3 was 1.12%, 0.82%, 0.48% and 0.90%, respectively. T2 was significantly lower than control, T3 (p<0.05) at the 50% of egg production. Ovary was $2.20{\sim}2.60%$ and oviduct was $2.98{\sim}3.45%$. In addition, ovary was $2.65{\sim}3.01%$, oviduct was $3.23{\sim}3.64%$ at the peak egg production, but there was no significant difference by non-feeding and feeding molting treatments. In blood component profile, cholesterol was $179.8{\sim}245.7\;mg/dL$ at pre-molting, but there was no significant difference and at post-molting, concentration of cholestrol in control, T1, T2 and T3 was 353.6, 229.1, 261.8 and 300.6 mg/dL, respectively. T1 was significantly lower than control and T3 (p<0.05). In addition, first laying day was $228.1{\sim}271.8\;mg/dL$, 50% of egg production was $236.5{\sim}284.8\;mg/dL$, there was no significant difference. Concentration of cholestrol in control, T1, T2 and T3 was 324.1, 591.6, 363.0 and 315.6 mg/dL, respectively, at the peak egg production period. T1 was significantly higher than other treatment (p<0.05).

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.2
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• pp.93-104
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• 2002

A field survey and experiment was conducted from 1996 to 1998 to develop rational technology for turfgrass vegetation of runway side of Incheon International Airport on the reclaimed tidal land in Young-Jong Island. Backfill of the experimental site was finished on August 1995. The experimental site was 8 ha located in the middle of the construction place for the main parking lot in front of the terminal building construction. The experimental field was drained by main open ditch, and divided three main plots, no subsurface tile drain, subsurface tile drain spacing with 22.5m, and with 45 m, respectively. The 17 sub plots were designed to test the effect of soil covering with red earth loam by 5 cm and 20 cm depth, application of chemical compound fertilizers and livestock manures, dressing of artifical soils and hydrophylic soil conditioners. The tested turfgrasses were three transplanting indigenous turfgrasses, Zoysia koreana, Zoysia sinica and Zoysia japonica, and two hydroseeding mixed exotic turgrasses, cool type I(tall fescue 30%, kentucky blue grass 40%, perenial ryegrass 30%), and cool type II(tall fescue 40%, perenial ryegrass 20%, fine fescue 20%, alkaligrass 20%). The soil backfilled with dredged seasand was sand textured with high salt concentration and low fertility. The soil showed high pH, low organic matter and low available phophate contents. The percolation rate was fast with high hydraulic conductivity. Desalinization was fast after installation of the main open drainage system. No subsurface tile drainage effect was found showing little difference in turfgrass growth. The covering and visual growth of turfgrasses were the best in the 20-cm soil covering with compound fertilizer treatment. The covering and visual growth of turfgrasses were satisfactory in the 5 cm soil covering with compound fertilizer treatment and with livestock manure treatments. The hydrophillic soil conditioner treatments were effective but expensive at present. The coverage and visual quality of turfgrasses were good for Zoysia koreana and Zoysia japonica. The coverages of turfgrasses by the hydroseeding with the mixed exotic turfgrasses were less than transplanting of native turfgrasses. In conclusion, for the runway side vegetation purposes, the subsurface tile drainage might not necessary as main open ditch drainage be sufficient due to fast percolation rate of the backfilled dredged seasand. The 5 cm soil covering with red earth might be sufficient for the runway side, but the 20 cm soil covering might be necessary for the runway side where high density of turfgrass coverage was necessary to protect from the airplance air blow.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.4
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• pp.245-256
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• 1978

The effects of different particle size distribution of fused phosphate on the changes of phosphorus content in soil and plant, growth and yield of paddy rice were investigated through pot and field experiments. The following results were obtained. 1. Negative correlation was found between unhulled rice yield and the composition of fused phosphate whose particle size was larger than 28 mesh, and 65 to 150 mesh, and highly significant correlation was found between unhulled rice yield and the composition of fused phosphate whose particle size was 28 to 48 mesh. But no significant correlation was found betweeen unhulled rice yield and the composition of fused phosphate whose particle size was 48 to 65 mesh. Thus the composition of 56% of 28 to 48 mesh particles and 44% of 48 to 65 mesh particles would give the best effect. 2. In the soil of the Jeonbug series rice plant in the plots treated with fine single textured fused phosphate showed poor early growth, i.e. poor tillering and short plant height. But at harvesting stage it showed rather increased number of tillers and higher plant height. Of the composite fused phosphate the more particles of 28 to 48 mesh it had, the better growth it showed. In the soil of the Yesan series rice plant in the treated plots showed much better tillering and higher plant height in contrast with that in the control plots. Of the single textured fused phosphate the finer particles showed better growth, while of the composite fused phosphate the more particles finer than 48 mesh it had, the poorer the tillering. 3. The content of available phosphorus in the soil tended to increase as the particles of both single textured and composite phosphate became finer. The soil phosphorus content decreased as the content of phosphorus absorbed by rice plant increased at each stage of growth, and the amount of soil phophorus decreased became larger as the the particles were finer. The amount of available phosphorus in the treated soils was larger in the soil of the Yesan series than in the soil of the Jeonbug series which was a long cultivated soil and contained relatively high phosphorus. 4. In the single textured fused phosphate the amount of phosphorus absorbed by rice plant tended to increase as the particles were finer, and great difference was found at heading stage, but at harvesting stage little difference was found for all the plots. In the field experiment in the soil of the Jeonbug series more phosphorus was absorbed by rice plant in the plots treated with the composite fused phosphate of higher content of 28 to 48 mesh particles. In the pot experiment the amount of phosphorus absorbed by rice plant was highest in the plots treated with the composite fused phosphate of 53.35% of particles larger than 48 mesh and 46.6% of particles smaller than 48 mesh. In the pot experiment in the Yesan series the amount of absorbed phophorus was highest in the plots treated with the fused phosphate of 47.75% of particles larger than 48 mesh and 50. 216% of particles smaller than 48 mesh. 5. A reverse relationship was found between the absorbed phosphorus and silica. In the pot experiment in the soils of both the Jeonbug and Yesan series the amount of phosphorus absorbed by rice plant increased as the particles were finer, while the amount of absorbed silica tended to decrease.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.3
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• pp.189-201
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• 1977

Some of basic aspects of soil potassium with special reference to soil physical properties were discussed. Data in the Official Soil Series Description(Korea) was analyzed according to soil type, land form, and soil texture to find soil potassium status which may explain different response to potassium application. Exchangeable potassium contents decreased with soil depth irrespective of soil type, land form and soil texture. Change in degree of potassium saturation within soil profile was not so clear as exchangeable potassium but the degree of potassium saturation of A horizon was highest among soil horizon. Soils of terrace and mountain foot slope showed high values both in exchangeable potassium and degree of potassium sauration and only these two soils were classified as soils having exchangeable potassium higher than 0.3 meq per 100g of soil and degree of potassium saturation higher than 5.0%. Exchangeable potassium of fine loamy and fine clayey soils is higher than 0.3 meq per 100g of soil but degree of potassium saturation is lower than 4.0%. Degree of potassium saturation of sandy soils exceeds 5.0% but exchangeable potassium is very low. Soils of rolling, hilly, unmatured and alpine land soils have lower exchangeable potassium and show lower degree of potassium saturation. The highest distribution of exchangeable potassium content irrespective of soil horizons was shown in the range of 0.1-0.2 meq per 100g of soil. The highest distribution of degree of potassium saturation was in the range of 2.0-3.0% in A horizon and 1.0-2.0% in B and C horizons. Of the soil series concerned in this analysis, 27.3% in A horizon, 11.1% in B horizon and 4.0% in C horizon had exchangeable potassium higher than 0.3 meq per 100g of soil and 18.0% in A horizon, 6.3% in B horizon, and 4.1% in C horizon showed degree of potassium saturation higher than 5.0%. The low response of potassium application only to soils in terrace and mountain foot slope may be resulted from the high exchangeable potassium content and high degree of potassium saturation. It is concluded that a great response of potassium application to soils is expected especially in dry season.