40 THE MANURING OF ARABLE LAND [OH. 



Mangolds. The mangold is a very seductive crop because it 

 responds to liberal manuring; indeed, it gives more produce per 

 acre than any other. 



It is shown on p. 16 that mangolds need nitrogen in addition 

 to dung. Suitable dressings are: 



Up to 20 loads of dung, 



1 cwt sulphate of ammonia, 2 to 4 cwts superphosphate 



or basic slag 1 , 2 to 4 cwts salt in the drills; 

 1J cwts nitrate of soda as a top dressing when the plants 

 are hoed and singled. 



On peaty soils or heavy clay soils in cool, wet districts, the 

 sulphate of ammonia can be omitted and the phosphate increased. 

 Slag is then better than superphosphate. 



On black fen soils, however, 6 cwts superphosphate alone, 

 without dung or other fertiliser, proves sufficient. 



Swedes and turnips. It was the turnip crop that revolutionised 

 British farming nearly 200 years ago, but if south country and 

 East Anglian farmers kept closer accounts some of them would 

 begin to ask whether it has not outstayed its welcome. It may 

 be doubted whether crops of swedes and turnips under 20 tons per 

 acre bring in sufficient revenue to pay the cost of production. 

 The problem of finding a substitute is one for the future ; mean- 

 while we have to make the best of the crop as we have it. 



The main expense is the cultivation, and this is the same 

 whether the crop is large or small. 



The chief factor limiting the yield is the climate : no amount 

 of manuring can get over this difficulty. 



If the climate allows more than 20 tons per acre liberal manuring 

 may be adopted. A good dressing of dung can be given, supple- 

 mented by artificials rich in phosphates. 



Suitable dressings are: 



10 to 15 tons farmyard manure, 4 to 6 cwts superphosphate 



or basic slag 2 , 

 1 cwt sulphate of ammonia, in the drills. 



On peaty soils the sulphate of ammonia may be omitted, but, 



1 In the Northumberland ex])eriments basic slag was better than superphosphate. 



2 Basic slag is preferable to superphosphate wherever finger and toe is prevalent. 

 In some of the experiments it also gave roots of better feeding value. 



