30 



ROOT DEVELOPMENT IN THE GRASSLAND FORMATION. 



at no time was the water-content reduced to the hygroscopic coefficient 

 to a depth of 5 feet (Weaver, 1919). 



In table 2, water-content determinations at the Colorado Springs 

 station for 1918 and 1919 and at Lincoln for 1919 are recorded. The 

 former station is located on a nearly level tract of land and the latter is 

 on a level hilltop which represents upland-prairie conditions (plate 4). 

 In the table, only water in excess of the hygroscopic coefficient is given. 

 In the few instances where evaporation has depleted the water-content 

 of the surface soil to a point below the hygroscopic coefficient this 

 condition is indicated by the minus sign. 



Table 2. — Water-content of soils in excess of hygroscopic coefficient in true prairie at Lincoln 

 and mixed prairie at Colorado Springs. 



Date. 



0.0 to 0.5 foot. 



Colorado 

 Springs. 



1918 1919 



Lin- 

 coln. 



1919 



0.5 to 1 foot. 



Colorado 

 Springs;. 



1918 1919 



Lin- 

 coln. 



1919 



1 to 2 feet. 



Colorado 

 Springs. 



1918 1919 



Lin- 

 coln. 



1919 



June, second week 



June, third week 



June, fourth week .... 



July, first week 



July, second week 



July, third week 



July, fourth week 



August, first week 

 August, second week . 

 August, third week . . . 

 August, fourth week . . 

 September, first week . 



3.1 



1.5 



2.0 



-1.0 



-0.3 

 7.5 

 0.5 

 ■2.2 

 ■1.5 

 -0.9 



-0.3 



6.7 

 4.2 

 0.2 

 2.0 



16.6 



1L5 

 2.3 

 0.0 



-0.6 



4.4 



2.2 

 1.7 

 -0.6 

 0.3 

 3.5 

 2.7 

 -0.5 

 -1.3 

 -0.3 



Hygroscopic coefficient . 

 Wilting coefficient 



5.4 

 7.9 



5.4 

 7.9 



10.4 

 1.2 



9.5 

 14.0 



5.7 



8.4 



-0.4 

 0.3 

 0.0 

 1.4 

 0.3 

 7.0 

 2.9 

 3.0 

 6.5 



-2.4 



5.7 

 8.4 



16.6 



10.0 

 5.3 

 3.5 

 1.2 



2.0 



3.2 

 3.3 



8.7 

 12.9 



3.3 

 4.9 



3.9 

 3.5 



1.7 

 1.1 

 2.6 

 4.7 

 1.5 

 1.3 

 1.5 

 1.0 



3.3 



4.9 



9 5 

 9.2 

 5.2 

 1.6 



2.0 



2.2 

 3.4 



12.6 



Date. 



2 to 3 feet. 



Colorado 

 Springs. 



1918 1919 



Lin- 

 coln. 



1919 



3 to 4 feet. 



Colorado 

 Springs. 



1918 1919 



Lin- 

 coln. 



1919 



June, second week 



June, third week 



June, fourth week .... 



July, first week 



July, second week .... 



July, third week 



July, fourth week 

 August, first week 

 August, second week . 

 August, third week. . . 

 August, fourth week . . 

 September, first week. 



1.9 

 5.5 



1.3 



4.1 



9.9 

 10.7 



10.0 

 9.2 



4.1 



2.0 



3.2 



1.6 



0.6 



2.0 



7.1 

 3.3 



1.3 



1.0 



11.1 

 7.0 



Hygroscopic coefficient . 

 Wilting coefficient 



3.5 



5.1 



3.5 

 5.1 



5.4 

 5.6 



7.1 

 10.5 



4.4 

 6.5 



4.4 

 6.5 



5.4 

 8.3 



6.3 

 9.1 



1 Samples taken at a depth of 1.0 to 1.5 feet. 



