WEST OF ENGLAND EXPERIMENTS 111 



The mangels in these experiments in every case followed 

 wheat or some other corn crop. The plots were all one quarter 

 of an acre in extent. Each series of experiments had two un- 

 manured plots. The manures with which we are at present 

 concerned were : dung, 20 loads ; superphosphate, 4 cwts ; and 

 sulphate of ammonia, 3 cwts. per acre. Two-thirds of the 

 ammonia salt was applied at the time of sowing the seed, the 

 remainder as a top-dressing after singling. The following 

 table gives a selection of the average results obtained : 



TABLE XXXVII. 



AVERAGE PRODUCE OF MANGELS VARIOUSLY MANURED ON 

 TWENTY-THREE FARMS, IN 1890. 



Manures applied. I Av ege Produce of Roots 



: 



tons. cwts. 

 !^m 



... ... ... ... ... ... 15 14-4 



Superphosphate, Sulphate of Ammonia, 3 cwt. ... 24 6'6 



Farmyard manure, 20 loads... ... ... ... 23 10-3 



Farmyard manure, Superphosphate ... ... 24 9-8 



As the mangels were in this case grown on land in an 

 ordinary agricultural condition the unmanured produce is very 

 much larger than is shown at Rothamsted, and the manured 

 produce reaches in consequence a higher level. The crop 

 grown by 3 cwts. of sulphate of ammonia and superphosphate 

 is seen to be practically equal with that grown by 20 loads of 

 farmyard manure with superphosphate. The increase yielded 

 by the ammonia salt and superphosphate is 8 tons 12-2 cwts. 

 Towards this increase the superphosphate contributed but little. 

 On the nitrate of soda plots the 4 cwts. of superphosphate 

 increased the crop only i ton 17-6 cwts. above that yielded 

 by nitrate of soda alone. On the dunged plots, superphos- 

 phate added only about 3 cwts. to the produce. If we reckon 

 the superphosphate to have produced the same effect with the 

 sulphate of ammonia as it did with nitrate of soda the return 

 for i cwt. of sulphate of ammonia is 2 tons 5 cwts of roots. 

 If we disregard the effect of the superphosphate, the return is 2 

 tons 17*4 cwts. of roots. These returns are quite similar to 

 the average return at Rothamsted. 



There can be no doubt that if alkali salts had been used in 

 these experiments the return from the sulphate of ammonia 



