THE ROOT SYSTEMS OF CEREALS. 



123 



Table 10. — Development of rye, oats, and wheat at various stations in the grassland 

 formation — continued. 



Station. 



Variety of crop. 



Soil. 



Height 



of tops. 



Work- 

 ing 

 depth. 



Maxi- 

 mum 

 depth. 



Short-grass plains : 



Yuma, Colo 



Sterling, Colo . . . 

 Flagler, Colo. . . . 



Do 



Burlington, Colo. 



Colby, Kans 



Limon, Colo 



Do 



Turkey Red . 



do 



Red Spring . 

 Turkey Red . 



do 



Kanred 



Turkey Red . 

 Spring 



Silt-loam 1 . 



....do. 5 ... 



....do. 4 ... 



....do. 8 .. . 



do. 3 ... 



do. 7 . . 



do. 2 ... 



do. 2 ... 



feet. 

 2.1 

 2.0 

 2.5 

 1.0 

 2.5 

 3.2 

 1.8 

 1.7 



feet. 

 2.1 

 2.7 

 2.5 

 1.4 

 3.8 

 2.0 

 2.0 

 2.0 



feet. 

 2.3 

 2.8 

 2.8 

 1.5 

 5.4 

 2.3 

 2.8 

 2.0 



Averages . 



2.1 



2.3 



2.7 



II. 



Mixed prairie: 



Limon, Colo 



Ardmore, S. Dak . . 

 Phillipsburg, Kans. 

 Mankato, Kans 



Turkey Red . 



do 



do 



do 



Very sandy loam. 



Pierre clay 



Silt-loam 



do 



1.8 

 2.6 

 3.8 



2.8 



3.0 

 3.3 

 4.8 

 3.2 



4.0 

 4.1 

 5.7 

 3.7 



Averages . 



2.8 



3.6 



4.4 



III. True prairie: 



Lincoln, Nebr. . 



Do 



Do 



Fairbury, Nebr. 

 Wahoo, Nebr . . . 



Do 



Turkey Red . 



do 



do 



do 



do 



do 



Silt-loam 



Alluvial silt-loam 



Silt-loam 



Clay-loam 



Silt-loam 



do 



3.3 

 3.8 

 3.5 

 3.0 

 3.0 

 3.0 



3.2 

 4.4 

 4.9 

 3.0 

 3.6 

 3.8 



4.7 

 6.2 

 7.3 

 4.1 

 5.0 

 5.0 



Averages . 



3.3 



3.8 



5.4 



1 "Hardpan" at 3.6 feet. 



2 "Hardpan" at 2.5 feet. 



3 No "hardpan" found. 



4 "Hardpan" at 2.3 feet. 

 6 Gravel layer at 2.8 feet. 



6 "Hardpan" at 1.3 feet. 



7 "Hardpan" at 2.1 feet. 



For wheat the different environmental conditions have most pro- 

 foundly affected its development. Spring wheat at Flagler and 

 Limon have been included under short-grass plains, since their develop- 

 ment was quite similar to that of winter wheat. An examination of 

 table 10 shows that the data are fairly consistent throughout, except at 

 Burlington, Colorado, and in the mixed prairie at Phillipsburg, Kansas. 

 At the latter station the excess of precipitation above the normal is 

 pronounced (table 11), and the resulting increased water-content 

 reflects itself in the development of both wheat and oats. The general 

 relation of root penetration to the depth of moist soil rather than to the 

 "hardpan" should be noted. 



In the absence of water-content data there is given in table 11a com- 

 parison of precipitation at the different stations during several periods. 

 The values of average mean annual precipitation are small for this 



