J. H. Gilbe 



Mutating 



HI* 



"'; 



,',r;a 



"•.M': 



,„,„, 





Quantities per acre, per annum. 



^■Suft'r 4 ' 8 



"•fiSS" I »-■ 



Farm ard Ma 



SS£ 



;;;; 



TliS 



;| 



E 





• 







• 



;,: 



Complex Min. Man. and 123 lbs. j 



C °Sgen M S'nifrate "* " ' bS ' f 





The figures in the Table conclusively show that the quantity 

 of nitrogen as nitrates per 100,000 parts of the drainage water, 

 increased in very direct proportion to the increase in the amount 

 of ammonia or nitrate supplied, and it is obvious that there has 

 been a considerable loss of the nitrogen of the manures by 

 drainage. But as the subsoil rests upon chalk not many feet 

 below the surface, and there is, therefore, natural drainage con- 

 Btently going on, even when there is no flow from the pipes, it 

 ^it>i -ii.h ll( u ( t, u - ,, .-mute the total amount of drainage, 

 and therefrom the total amount of loss. Other experiments at 

 Rothamsted, however, lead to the conclusion that, according to 

 season, from one-quarter to nearlv one-half of the annual rain- 

 tall may pass heh.w 40 inches. Now. supposing drainage water 

 to contain one part of 8 per 100,000 parts of 



water, an inch of rain passing beyond the reach of the roots 

 would carry with it 2| lbs. of nitrogen per acre; and it is obvi- 

 ous that if from seven to ten inches passed annually of that av- 

 erage strength, the loss would be very great In reference to 

 this point it is of much interest to observe, that in the Report 

 °f the River's Pollution Commission already referred to, Dr. 

 Frankland gives a series of analyses of land drainage waters 

 collected at Rothamsted, at depths of twenty, fo 

 inches, respectively ; and those collected at twei 

 iably show much more nitrogen as ni 

 either forty or sixty inches. 



•ty, and sixty 

 it'y inches, a'l- 

 tr'icaeid than 

 juld thus ap- 

 be indicated that a considerable amount of nitric acid 

 —i arrested in the soil below the depth of twenty, inches. 

 further, determinations of nirnmen in rh.- -oil.- do show some 

 accumulation. Indeed, it would appear probable, that the whole 

 °f the nitrogen applied to the wheat as ammonia salts or nitrate 



those tab 

 pear to 1 



