v] ARTIFICIALS FOR HAY 51 



Dung not available, artificials to be used. Usually the difficulty 

 on the farm is to get enough dung, and fortunately grass land 

 can do perfectly well without it, so that the whole supply can, 

 if necessary, be used for roots or other crops. Artificials also 

 produce very definite effects on the herbage, and under skilful 

 management the farmer can succeed in altering it to a considerable 

 extent to suit his own requirements. The general rule is that 

 nitrogenous manures give bulk, while phosphates and potash 

 give quality, and by a judicious combination the farmer may to 

 some extent achieve both. 



The most suitable nitrogenous manures for producing bulk of 

 herbage are nitrate of soda, sulphate of ammonia, and the new 

 fertilisers nitrolim and nitrate of lime. Many farmers have ob- 

 tained hay for a number of years simply by applying f to 1J cwts 

 of nitrate of soda per acre and nothing else to the land. 



But this scheme cannot be recommended because it causes 

 serious deterioration of the herbage. At Rothamsted one of the 

 plots has long received 2J cwts of nitrate of soda per acre each 

 year: an average yield of 34 cwts of hay has been maintained, 

 but there has been a marked falling off in the quality ; the clover 

 has decreased, and the weeds have increased so much that they 

 now make up more than 30 per cent, of the whole (Fig. 9). 



Sulphate of ammonia used by itself produces equally undesir- 

 able results. On the average the yield is practically the same 

 as with nitrate of soda 36 cwts per acre though it has not kept 

 up so well of late years ; clover has entirely disappeared, and the 

 grass is mainly sheep's fescue. 



When nitrate alone is used in practice the falling off in quality 

 shows itself in the great variety of herbage and the number of 

 flowers ; ox-eyed daisy, scabious, bird's-foot trefoil, hawk-bit, and 



42 



