26 



CHARACTERISTICS OF AMMONIA SALTS 



in ten series of analyses of drainage waters collected at various 

 times during several years from the plots in the experimental 

 wheat field at Rothamsted. The mean proportion of lime and 

 magnesia found in the ten analyses, in the case of five of the 

 plots, is shown in the following table. The quantity of lime 

 removed annually in the drainage water is calculated on the 

 assumption that the annual discharge of drainage water in the 

 wheat field will amount to 8 inches per acre. 



TABLE IV. 



AVERAGE AMOUNT OF LIME IN DRAINAGE WATERS FROM PLOTS 

 VARIOUSLY MANURED IN THE WHEAT FlELD at ROTHAMSTED. 



It is plainly seen from the above figures that the use of 

 ammonia salts has in every case considerably increased the 

 quantity of lime removed in the drainage water, and this 

 quantity is clearly proportional to the weight of ammonia 

 salts employed. The mean result of the ten analyses cannot 

 of course be taken as representing the true average composi- 

 tion of the drainage waters, which vary extremely in their 

 character, nor can the estimated amount of drainage be taken 

 as strictly correct. The general teaching of the results is, 

 however, unmistakeable. The 71 Ibs. of lime removed by 200 

 Ibs. of ammonia salts would be equivalent to 126 Ibs. of car- 

 bonate of lime per acre. 



The removal of carbonate of lime arising from the use of 

 sulphate of ammonia is attended with objectionable results 



* By cinereal manure is meant one supplying the ash constituents of 

 the crop; in this case the manure supplied potash, soda, lime, and 

 magnesia as sulphates or phosphates. 



