372 



Journal of Agricultural Research 



Vol. XII, No. 6 



in August. The samples of soil used in this work were identical with 

 those employed by Stewart in making water extractions. In general, 

 the moisture contents of the uncropped and cropped soils were very 

 similar, but it was not always feasible to keep them in absolute agree- 

 ment. The data are therefore presented in two forms: First, as a table 

 showing the observed depressions and actual percentages of total moisture 

 present, together with the corresponding osmotic pressures and parts 

 per million of total solids in solution, as calculated by the methods of 



(&ASIS or a2'/« noiSTURC) 



time: from 

 plantiino. 



(bASISaOF ZZ.'/' nOlSTURE) 



I0WIC5 12WKS I6WKS 

 JULIO. JUL24 AUG 21 



51WKS time: FRom 



MAY. 1 PLANTING. 



Fig. I. — Graphs of the depressions of the freezing point in soils i and 2, with and without crop. 



Bouyoucos and McCool. In the second place, the observed depressions 

 have been calculated to uniform moisture contents, 17 per cent for all 

 of the fine sandy loams and 22 per cent for the silty clay loams. In mak- 

 ing these estimates the percentages of unfree water already presented 

 have been used. The corrected depressions have been plotted for each 

 pair of soils. In this way the cropped and the uncropped soils, as well 

 as the different soils in each group, may be compared readily (fig. 1-8). 

 (Cf. Table III.) 



