The Pinole series consists of very deep, well drained soils that formed in alluvium derived from mixed rock sources. These soils are on river terraces. Slopes range from 2 to 15 percent. The mean annual precipitation is about 45 inches, and the mean annual air temperature is about 56 degrees F.

These soils are classified as fine-loamy, mixed, thermic Ultic Argixerolls.

Typical pedon of Pinole loam, 2 to 9 percent slopes, 2,250 feet south and 2,200 feet east of the northwest corner of sec. 11, T. 14 N., R. 15 W., MDBM, Boonville Southwest quadrangle:

A1—0 to 5 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; strong fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular and interstitial pores; 2 percent hard rounded, subrounded, and subangular gravel; moderately acid (pH 5.8); abrupt wavy boundary.

A2—5 to 10 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular and few very fine interstitial pores; 2 percent hard rounded, subrounded, and subangular gravel; slightly acid (pH 6.2); clear wavy boundary.

Bt1—10 to 19 inches; yellowish brown (10YR 5/4) clay loam, brown (7.5YR 4/4) moist; strong medium and coarse subangular blocky structure; hard, firm, sticky and plastic; common very fine roots; many very fine tubular and few fine interstitial pores; common thin clay films on faces of peds and lining pores; 2 percent hard rounded, subrounded, and subangular gravel; slightly acid (pH 6.3); gradual wavy boundary.

Bt2—19 to 26 inches; strong brown (7.5YR 5/6) clay loam, brown (7.5YR 4/4) moist; strong medium and coarse subangular blocky structure; hard, firm, sticky and plastic; few very fine roots; many very fine tubular and few fine interstitial pores; many moderately thick clay films on faces of peds and lining pores; 2 percent hard rounded, subrounded, and subangular gravel; slightly acid (pH 6.5); gradual wavy boundary.

Bt3—26 to 52 inches; strong brown (7.5YR 5/6) clay loam, brown (7.5YR 4/4) moist; strong medium and coarse subangular blocky structure; very hard, very firm, sticky and plastic; many very fine tubular and few fine interstitial pores; continuous moderately thick and thick clay films on faces of peds and lining pores; 2 percent hard rounded, subrounded, and subangular gravel; slightly acid (pH 6.5); gradual wavy boundary.

Bt4—52 to 62 inches; variegated brownish yellow (10YR 6/6) and strong brown (7.5YR 5/6) clay loam, yellowish brown (10YR 5/6) and brown (7.5YR 4/4) moist; common fine and medium subangular blocky structure; hard, firm, sticky and plastic; few very fine roots; common very fine tubular pores; common moderately thick clay films on faces of peds and lining pores; 2 percent hard rounded, subrounded, and subangular gravel; strongly acid (pH 5.5).

The depth to bedrock is more than 60 inches. The mean annual soil temperature ranges from 59 to 62 degrees F. The mollic epipedon is 10 to 20 inches thick and has 1 to 5 percent organic matter. The soil between the depths of 6 and 17 inches is moist in all parts from November 1 to May 1 and is dry in all parts from June 1 to October 1 in most years. Reaction is moderately acid or slightly acid throughout.

The A horizon has color of 10YR 5/2 or 5/3. Moist color is 10YR 3/2 or 3/3. The content of clay ranges from 15 to 27 percent. The content of gravel ranges from 2 to 10 percent. Base saturation ranges from 50 to 75 percent.

The Bt horizon has color of 10YR 5/4, 6/4, or 6/6 or 7.5YR 4/6 or 5/6. Moist color is 10YR 4/4 or 5/6 or 7.5YR 3/4, 4/4, or 4/6. The texture is sandy clay loam or clay loam. The content of clay ranges from 25 to 35 percent. The content of gravel ranges from 2 to 15 percent. Base saturation ranges from 60 to 90 percent.