266 SOILS: PROPERTIES AND MANAGEMENT 



as plant-food. The quantity of nutrient elements lost 

 annually from the average soil in a humid region more 

 than equals that withdrawn by the crops. The results 

 from the Rothamsted drain gauges x from 1871 to 1904 

 on a clay loam soil of three different depths are inter- 

 esting as to the light that they afford regarding actual 

 drainage losses : — 



The rainfall and relative loss through the 40-inch depth 

 of soil is shown graphically in the following diagram : — 



1 Hall, A. D. 

 pJ 23. London. 



The Book of the Rothamsted Experiments, 

 1905. 



