REMOVAL OF NUTRIENTS FROM THE SOIL 305 



play. In total concentration, drainage water seldom exceeds 

 500 parts per million. It is thus much more dilute than the 

 average soil solution. This difference holds for the separate 

 constituents as well as for the concentration in toto. 



The following data, as compiled by Hall, 1 give some idea 

 of the quantitative composition of the drainage water from 

 the clay loam soil of the Rothamsted Experimental Farm. 

 The drainage water was obtained from tile drains, a line of 

 which extended under each of the variously treated plats. 

 The data is a mean of five collections, 1866 to 1868. 



Table LXVII 



It is immediately noticeable that ammoniacal nitrogen and 

 phosphoric acid are lost in drainage to but a slight degree. 

 Calcium appears in the highest concentration with sulfur 

 next. Nitrates and potash are present in appreciable quan- 

 tities but are quite variable. 



The influence of treatment is particularly obvious on the 

 parts per million of nitrate nitrogen, lime, and sulfur appear- 

 ing in the drainage, the addition of farm manure increasing 

 all of these constituents as well as the concentration of the 

 potash, soda, and chlorine. The application of sodium nitrate 

 increased the nitrate nitrogen as well as the soda, potash, and 



1 Hall, A. D., The Booh of the Bothamsted Experiments; pp. 237-239, 

 New York, 1917. 



2 By minerals are meant the phosphoric acid, potash, lime, and other 

 constituents left as ash when plants are burned. 



