WEONGOG SERIES

Established Series

BCO, UKT

21 April, 1970

The Weongog series is a member of the fine loamy, mixed, mesic, acid, family of Fluventic Dystrudepts (Regosols).  These soils have moderately thick, brown to dark brown loam to sandy loam Ap or A horizons and deep yellowish red or dark reddish brown loam, clay loam and silty clay loam cambic B horizons with weakly developed structure.  The C horizons are very thick yellowish red to dark reddish brown fine loamy materials.  They are developed in narrow valley and foot slope positions in local alluvial-colluvial and alluvial fan derived from granitic materials.

Typifying Pedon : Weongog loam-ginseng (Field description Gimpo Gun profile No. 62; colors are for moist soil).

Ap1	--	0 to 11 cm.  Brown to dark brown (7.5YR 4/4) loam; weak, fine to medium granular structure; friable, slightly sticky and slightly plastic; few fine quartz gravel; common fine dead roots; clear smooth boundary; pH 5.3.

Ap2	--	11 to 22 cm.  Brown to dark brown (7.5YR 4/4) loam; weak, medium to coarse granular structure; slightly firm, slightly sticky and slightly plastic; few fine vesicular pores; few fine white mica; few fine dead roots; gradual smooth boundary; pH 5.7.

BA	--	22 to 53 cm.  Yellowish red (5YR 4/6) light clay loam or heavy loam; weak, coarse subangular blocky structure breaking to medium to coarse granular structure; firm, sticky and plastic; common fine pores; few medium earth worm holes with worm cast; few fine white mica; very few fine roots; few fine quartz gravel; gradual smooth boundary; pH 5.7.

B	--	53 to 93 cm.  Yellowish red (5YR 4/8) light clay loam to heavy loam; weak, coarse subangular blocky structure; firm, sticky and plastic; few fine pores; common fine mica; very few very fine roots; diffuse smooth boundary; pH 5.7.

BC	--	93 to 130 cm.  Dark reddish brown (5YR 3/4) silty clay loam; structureless (massive); firm, sticky and plastic; few fine pores; non roots; few fine white mica ; pH 5.7.

Type Location : In front of Jangrim Burag, Dosa Ri, Yangchon Myeon, Gimpo Si, Gyeonggi Do.

Range in Characteristics : Solum thickness ranges from 100 to 150 cm. and depth to hard rock is greater than 2 meters.  Coarse fragments (grit and gravel) are less than 10 percent throughout the solum and generally increase slightly with depth.  Base saturation is less than 60 percent.  Reaction is strongly to medium acid.  A or Ap horizons are 20 to 30 cm. thick, brown to dark brown loam, sandy loam or sandy clay loam.  The cambic B horizons are yellowish red, dark reddish brown, red, reddish brown or dark red loam, light clay loam, clay loam or silty clay loam with less than 10 percent gravel.  Clay content of this horizons are between 18 to 35 percent.  Few or common fine white and yellow mica occur throughout the profiles.  C horizons are stratified yellowish red, dark reddish brown or brown to dark brown silty clay loam, loam, clay loam, sandy loam or very fine sandy loam.

Competing Series and Their Differentiae : These are the Pogog, Seongsan, Sangju, Anmi, Jangweon, Maji, Anryong and Togye series.  The Pogog soils have fine clayey texture family, hard pan and restricted moisture and plant root movement.  The Seongsan and Sangju soils are in the coarse loamy family, have brown, strong brown, dark yellowish brown colors and high base saturation.  The Anmi soils have slightly acid to neutral reaction and are formed in local alluvial materials from limestone soils.  The Jangweon soils have fragipan horizons and restricted moisture and plant root penetration.  The Maji soils have loamy skeletal texture, higher reaction and are formed in limestone areas. The Anryong soils have fine loamy textures and argillic B horizons.  The Togye soils have sandy texture family and lighter colors.

Setting : The Weongog soils occur in gently sloping to sloping local valley and on foot slopes in local alluvial-colluvial and alluvial fan positions in materials washed mainly from red granitic soils.  Dominant slopes are 2 to 7 percent and range from 2 to 30 percent.

Principal Associated Soils : The Songjeong, Osan, Bancheon, Jeonnam, Dalcheon and Jisan soils are associated.  The red Songjeong, Osan, Bancheon, Jeonnam and Dalcheon soils in upland positions are the dominant source materials.  The Jisan soils are associated in local valley positions.

Drainage and Permeability : Well drained.  Runoff is moderate depend on slope gradient and permeability is generally moderately slow.

Use and Vegetation : Most areas are used for ginseng, red pepper, soybean, radish, corn, sorghum, eggplant, barley and wheat.  Grape is sometimes grown.

Distribution and Extent : The Weongog soils are of small extent though they occur in many small areas in local valleys associated with red soils derived mainly from granite gneiss and schist materials.  They occur chiefly in the midwest and southwest part of the country.

Series Established : Gimpo Gun, Gyeonggi Do, November 1969.

Lab. Nos. Ar 206-210 Typifying Pedon

Depth cm	Hor- izon	Gravel >2㎜	Particle Size Distribution 1/(㎜)%
			U.S Department of Agriculture								International
			VCS 2-1	CS 1- .5	MS .5- .25	FS .25- .10	VFS .10- .05	Silt .05- .002	Clay <.002	Tex- tural Class	CS 2- .2	FS .2- .02	Silt .02- .002	Tex- tural Class
0- 11 11- 22 22- 53 53- 93 93-120	Ap1 Ap2 BA B BC	8.9 7.4 3.9 2.7 0.7	3.6 3.7 4.1 6.2 4.0	9.5 9.7 13.2 11.1 7.1	13.2 12.5 13.1 8.9 6.9	2.2 12.4 6.3 5.7 1.5	20.2 8.2 3.9 3.6 6.4	38.4 38.6 35.2 39.9 43.5	12.9 14.9 24.2 24.6 30.6	L L L L CL	28.2 27.5 31.5 27.1 18.9	40.6 36.9 21.8 26.1 20.5	18.3 20.7 22.5 22.2 30.0	FSL L CL CL LiC

Moisture Retention %				pH		O.M. %	2/ CEC	Extractable Cations						Base Sat. %
1/10 atms	1/3 atms	15 atms		H2O (1:1)	1N KCl			Ca	Mg	Na		K	H
							----------- me/100g -----------
26.2 28.9 28.9 29.5 32.6	20.0 21.3 23.1 25.9 29.2	7.5 14.0 19.7 12.2 14.2		4.5 4.5 5.2 5.2 5.1	3.4 3.4 3.7 3.8 3.6	1.46 1.30 1.06 0.84 1.19	7.00 7.90 9.00 8.20 10.60	2.00 2.00 2.50 2.63 2.38	0.48 0.65 1.25 1.68 1.60		0.15 0.08 0.08 0.25 0.38	0.75 0.65 0.50 0.15 0.18	- - - - -	48.3 42.8 48.1 57.4 42.8

1/ Pipette Method, Sodium Hexameta-Phosphate.

2/ Ammonium Acetate Method.