34 



FIELD OPERATIONS OF TIIK lUTREAU OF SOILS, 1919. 



brown to ^I'Uowish-hrown clay loiuii having a <rrayish chalky ap- 

 penraiK-e wlien ilry. Calcareous nodules are found quite generally 

 thr()U<:hout the .sul)soil section. The surface soil usually <rives an 

 alkaline reaction. The Mack soil stratum in places occupies the en- 

 tire 3-foot depth. The suiface soil is not always uniform in texture, 

 sand and <xra\el particles hcinn^ incorporated in places. 



The type usually occupies the (lat and (lei)ressed areas at the back 

 of the lower terraces abutting on the uplanil. Narrow strips lie along 

 the Towa T\iver through its course in. the county, but are nowhere 

 continuous for any great distance. The largest area, covering about 

 200 acres, is situated on a small creek 2^ miles southwest of the point 

 where the Towa Tviver leaves the county. Small areas are found west 

 and south of Kagle Grove along Boone Kiver. 



The natural drainage is not suflicicnt for maximum crop pro- 

 duction, and tile drains must be used to carry away the excess w^ater. 

 Many of these areas Avere formerly ponds, and a few are still un- 

 drained. The soil is very productive, crop yields being comparable 

 with those on the strong upland soils. This type is usually farmed 

 in fields with the sandier terrace types. 



The following table gives the results of mechanical analyses of 

 samples of the soil, subsurface, and subsoil of this type. 



Mcrlnniical aiuiliifcx of Favfio .'^ilfu clay loam. 



BUCKNER LOAM. 



The Buckner loam consists of a browm to dark-brown loam, passing 

 at 10 to 14 inches into a yellowish-brown sandy loam to fine sandy 

 loam. The soil section contains coarse sand and small gravel at all 

 dejiths. but in greater quantities in the Iowtf part. Small pieces of 

 white flint rock particles occur in the subsoil occasionally. No 

 calcareous material is present. 



The Buckner loam is underlain by gravel at 4 to 6 feet below 

 the surface. Pockets of gravel occur here and there throughout the 

 type under small depressed areas, and occasionally can be reached 

 w-ithin the 3- foot section 10 to 20 feet back from the overflow lands. 



Among the terrace soils the Buckner loam is second in extent of 

 area, the O'Neill loam being first. It occurs along the entire course 



