32 Experiments upon Swedes. 



taken up, the guano turnips were at least 3 inches higher in tops, 

 and promised, so far as appearance went, the heaviest crop ; 

 but the weighing showed that the yield in bulbs was smaller 

 than that of the plots manured with superphosphate free from 

 nitrogen. 



It appears in these experiments : 



1. That ammoniacal salts like sulphate of ammonia, used 

 alone, had a decidedly injurious effect upon the turnip-crops, 

 even when used in small quantities. 



2. That ammoniacal manures applied to the turnips in the 

 experimental field, kept back at first the turnip-crop, and had no 

 beneficial effect either alone or in conjunction with phosphates. 



3. That guano proved a less economical manure than super- 

 phosphate. 



4. That the addition of salt to superphosphate is likely to be 

 attended with beneficial results when used for turnips. 



5. That, in dry seasons, the best artificial manures often 

 produce hardly any greater effect upon roots, and may produce 

 even less, than inferior and all but worthless manure. 



6. That the value of an artificial manure, and its special effect 

 upon different crops, cannot be determined by a single field- 

 experiment. 



In conclusion, I would observe that I intend continuing 

 similar experiments on swedes for a number of years, and 

 hope, on a future occasion, to present to the Society another 

 Report on this subject. 



AUGUSTUS VOELCKER. 

 Royal Agricultural College, Cirencester, 

 June, 1858. 



LONDON: PRINTED BT W. CLOWES AND SONS, STAMFORD STREET, 

 AKD OHARING CROSH. 



