92 RESULTS WITH GRASS 



sulphate of ammonia applied alone gave an excellent return, 

 amounting to 12 cwts. of hay per i cwt. of sulphate. The 

 largest crop was reached when superphosphate and potash salt 

 were added to the sulphate of ammonia. 



On two of the farms the second crop of hay was weighed ; 

 in these cases the author has calculated the profit per acre 

 resulting from the use of the various manures. 



TABLE XXIX. 



PROFIT PER ACRE PROM APPLICATION OF MANURES TO RYE 

 GRASS AND CLOVER, MEAN OF Two FARMS, 1897. 



It will be noticed that the greatest profit w r as obtained when 

 a mixture of superphosphate, muriate of potash, and sulphate 

 of ammonia was made use of. In these calculations the cost 

 of the whole of the manures applied, and not of the ammonia 

 salt only, is taken into the account. 



5. Influence of Ammonia Salts on the Composition 

 of Hay. The effect which manuring with ammonia salts has 

 on the quality of the hay has been already noticed in part. We 

 have seen that ammoniacal manures tend strongly to increase 

 the proportion of the true grasses, and to reduce the propor- 

 tion of clover and weeds. This effect is not very marked 

 when only small quantities of ammonia salts are applied, as 

 in the experiments at Pumpherston, but becomes very striking 

 when considerable quantities are used every year, as in the 

 Rothamsted experiments. 



The presence or absence of a full supply of the ash con- 

 stituents of grass determines a marked difference on the plots 

 receiving ammonia salts. Where ash constituents are absent 

 the growth of grass is practically limited to the production of 



