XI.] 



MANURES FOR BARLE V 



309 



small crop of roots had been fed, gave the best results ; 

 the third plot, on which a large crop of roots had been 

 fed, evidently received too much nitrogen, as shown 

 by the high percentage in the grain ; as a result the 

 value fell off. The figures are the means of several 

 years' valuations. 



Table XC— Relation of Quality of Barley to the Nitrogen 

 si'prLiED IN Manure (Rothamsted). 



In preparing for a crop of barley of high quality it 

 is therefore necessary not to allow the land to become 

 really poor, but it is desirable that the nitrogen should 

 come more from condition in the land than from very 

 active manures. If the land is in really high condition 

 before the first straw crop of wheat or oats is taken, 

 barley may follow without any fertiliser, especially 

 if the ground can be got into good tilth and the 

 barley sown really early. But for a second barley 

 crop or for the first on land in poorer heart some 

 nitrogenous manure must be used, and sulphate of 

 ammonia and rape cake are found to give better 

 quality than nitrate of soda, though in neither case 

 must a large quantity be used. Furthermore, it has 

 been shown earlier (p. 140) that phosphoric acid is a very 

 essential constituent of any fertiliser for barley, and 



