312 SYSTEMS OF MANURING CROPS [chap. 



season as much as 2 cvvts. per acre of nitrogenous manure 

 might easily result in the crop going down. 



Rye, which is grown in the south of England for 

 early spring keep is rarely manured ; but 7naize, which is 

 also grown to some extent as fodder, requires the land 

 to be brought into fairly high condition. A preliminary 

 dressing of 12 to 15 loads of dung per acre should be 

 given, with 2 to 3 cwts. per acre of superphosphate at 

 the time of sowing, then i cwt. per acre of nitrate of 

 soda may be used as a top dressing round the plants 

 when they are set out and side hoed. 



Root-crops. — In British farming the bulk of the 

 manure that is made upon the farm or purchased is 

 applied to the root-crops — Swedes or mangolds ; though 

 in the east and south-east of England it is more general 

 to apply the farmyard manure to the seeds before 

 ploughing up for wheat. In these warm soils much 

 nitrogenous manure is apt to cause Swedes to run to 

 top and to be more susceptible to mildew. Big crops 

 of roots mean more food for the stock, and so in turn 

 more farmyard manure. Moreover, the roots are grateful, 

 and continue to respond to liberal treatment without 

 lodging or growing an excess of straw, as cereal crops 

 will do. It is questionable, however, whether the very 

 common practice in the north of putting on all the 

 available manure, farmyard and artificial, for the root- 

 crop and making that serve for the whole of the rotation, 

 is wise ; better results will be obtained by a careful 

 adaptation of the fertiliser to the particular crops form- 

 ing the rotation. As regards Swedes, the earliest work 

 that was done at Rothamsted consisted in showing the 

 dependence of this crop upon an ample supply of 

 phosphatic manure of an available character, and it was 

 the response of this crop to soluble phosphates which 

 built up the superphosphate and other artificial fertiliser 



I 



