168 



The Rothamsted Grass Experiments. 



merits with the nitrate were commenced two years later than 

 those with the ammonia-salts, so that the periods are 8, 10, 

 and 18, instead of 10, 10, and 20 years. 



TABLE XL. AVERAGE PER ACRE PER ANNUM, BY 550LB. NITRATE OP 

 SODA, AND MIXED MINERAL MANURE, INCLUDING POTASH ; PLOT 14. 



As in the two cases of ammonia-salts and nitrate, each 

 without mineral manure, so here, with mineral manure, there 

 is a much greater produce of hay when the nitrogen is applied 

 as nitrate of soda. There is also more mineral matter taken 

 up under the influence of the nitrate, but rather less nitrogen ; 

 and whereas with the ammonia-salts there is a decline in 

 annual yield of hay, and in the quantity of nitrogen and 

 mineral matter taken up, over the second period compared 

 with the first, there is, under the influence of the nitrate 



