n] DUNG v. ARTIFICIALS 19 



The addition of 6J cwts of artificials (1J cwts sulphate of 

 ammonia, 3 cwts superphosphate, and 2 cwts sulphate of potash) 

 gave only a small return in actual crop, but it improved the 

 quality, lessened the proportion of diseased tubers, and left a 

 bigger residue for the next crop : 



Garforth All centres 



tons cwts tons cwts 



10 tons dung 10 4 97 



10 tons dung + 6 cwts artificials 10 10 9 15J 



Complete 



Un- 10 tons 20 tons 10 tons dung artificials 

 manured dung dung + artificials alone 

 Marks for quality 50 40 29 48 40 

 Percentage of dis- 

 eased tubers 4-1 8-2 5-6 2-7 2-5 

 Next crop (Wheat) 



Grain, bushels 26| 31 36J 35 31fc 



Straw, cwts 20 25 32J 31 23 



Artificials alone proved satisfactory, giving not only good crops 

 but also good quality: 



Garforth Other centres 



tons cwts tons cwts 



10 cwts artificials 11 11 9 14J 



Unmanured 8 10J 6 3f 



Dung v. Artificials. In the 'sixties and 'seventies of the last 

 century there was controversy as to whether dung or artificials 

 were best. That is now settled in the way such controversies 

 usually end : each side was shown to have a good deal of the truth, 

 but not all the truth. The experiments already quoted show that 

 a large dressing of dung 20 tons or so is not much more effective 

 than a smaller one 10 tons while the best results are obtained by 

 combining dung and artificials. This holds over the whole rotation. 



Further examples will be given in a later chapter : meanwhile 

 we need only emphasise that the large dressings of dung which 

 some of the potato growers in the Home Counties found necessary 

 when first they took the land over in poor condition, could well 

 be reduced now that its price has gone up and transport diffi- 

 culties have increased. 



Residual effects. The farmer naturally expects the benefit of 

 a dressing of dung to last throughout the rotation. The effects 

 on the soil last for some years, but the supply of plant food may not. 



22 



