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CIRCULAR 303, U.S. DEPARTMENT OF AGRICULTURE 



The water-laid soils of group 2, particularly the Collamer soils, show- 

 wider variations in subsoil conditions than are found in the soils of 

 till origin. 



In figure 9 is shown the root development of a Baldwin tree 71 years 

 old having a trunk 92 inches in circumference and grown on Collamer 

 silt loam, a soil of group 2 developed from water-laid material. 



Heavy rooting near the surface and an abundance of large roots will 

 be noted. In the G and D layers the rooting is light. In the thin 

 layer of reddish-brown clay it is heavy, and in the grayish-brown 

 very compact fine sandy loam roots are almost entirely lacking. Max- 



ROOTS MORE THAN ONE INCH IN DIAMETER •• SMALLER ROOTS AND ROOTLETS 



BETWEEN ONE HALF AND ONE INCH IN DIAMETER ® LARGE DEAD ROOTS 



X SMALLER DEAD ROOTLETS 



Figure 10.— Root penetration of a Baldwin apple tree grown on a heavy phase of Collamer silt loam: 

 A, dark grayish-brown heavy silt loam; B, light-brown silt loam; C, dull reddish-brown silty clay 

 slightly mottled with gray in the upper part; D, an irregular mass of olive-brown silt; E, brown clay; 

 and F, olive-brown compact silt and very fine sandy loam reached at a depth of 3 feet at one end of the 

 excavation and at 6 feet at the other. 



imum root penetration is about 6 feet but is scant below 3 feet. In 

 this orchard surface drainage is good, the soil has been heavily ma- 

 nured, and the orchard has been productive. 



In figure 10 is shown the root development of a Baldwin apple tree 

 75 years old, with a trunk girth of 86 inches, grown on a heavy type 

 of Collamer silt loam. The gray layer is not very strongly developed, 

 and the impervious subsoil is rather deep. 



Figure 11,-4, shows a Baldwin apple tree 71 years old, 92 inches in 

 circumference, grown on Collamer silt loam; and figure 11, B, shows 



