THE ABSOBPTIVE PROPEBTmS OF SOILS 351 



one of each being fertilized and one unfertilized. The 

 lysimeters were 1.2 meters deep and contained 4 cubic 

 meters of soil. The drainage water was caught and 

 analyzed for four years. The first year there was no 

 crop, the second year potatoes were grown, the third 

 oats, and the fourth rye. The following results were 

 shown : — 



Average Composition of Drainage Water in Parts per 



Million 



Soil 



Treatment 



Total 



NiTBOGEN 



Nitric 

 Nitrogen 



0EG4.NIC 



Nitrogen 



K2O 



CaO 



Moor soil . . 



Loamy sand 

 low in huinus 



Sandy loam 

 Mgh in humus 



j Fertilized 

 [ Untreated 



j Fertilized 

 I Untreated 



j Fertilized 

 \ Untreated 



32.7 

 65.0 



25.5 

 20.9 



67.8 

 69.5 



30.0 

 60.3 



25.1 

 20.4 



64.6 

 66.1 



2.7 

 4.7 



0.4 

 0.5 



3.1 

 3.4 



32.2 

 26.2 



25.1 

 8.5 



70.2 



47.4 



405 

 507 



92 

 90 



399 



414 



x^bsorption will not proceed to an unlimited extent. 

 A soil will cease to absorb any particular substance after 

 a certain quantity has been taken up. This quantity 

 will vary with every soil. Clay and loam soils have 

 greater absorptive power than sandy soils. This differ- 

 ence, both as to amount and as to rate of absorption, is 

 well shown by the following curves adapted from Schreiner 

 and Failyer.-^ 



1 Schreiner, O., and Failyer, G. H, The Absorption of 

 Phosphates and Potassium by Soils. U. S. D. A., Bur. Soils, 

 Bui. 32. 1906. See also Cameron, F. K., and Bell, J. M. 

 The Mineral Constituents of the Soil Solution. U. S. D. A., 

 Bur. Soils, Bui. 30, pp. 42-66. 1905. Patten, H. E., and Wag- 

 gaman, W. H, Absorption by Soils. U. S. D. A., Bur. Soils, 

 BuL 52. 1908. 



