Experiments upon Swedes. 29 



was uniform in its character, and also that gypsum had no effect 

 whatever on the turnip-crop. 



Plot XII. Manured with 3 cwt. of home-made superphos- 

 phate : 



Produce .. 10 tons 12 cwt. 21 Ibs. 



Increase .. 4 tons 1 cwt. 25 Ibs. 



The superphosphate used in this experiment was made on our 

 farm from coprolites, fine bone-dust, sulphuric acid, and salt. 

 It yielded on analysis 



Water 22'83 



* Organic matter 4'88 



Bi-phosphate of lime 8*28 



Equal to bone-earth, rendered soluble by acid .. (12-91 ) 



Insoluble phosphates 16'21 



Hydrated sulphate of lime 37'42 



Alkaline salts (common salt) 5*53 



Insoluble silicious matter (sand) 4*85 



100-00 



# Containing nitrogen -55 



Equal to ammonia *66 



It will be observed, that this superphosphate contains little 

 ammonia, and about 5J per cent, of salt besides soluble and 

 insoluble phosphate. In its effect upon the crop it was nearly 

 equal to the superphosphate used in Plot VII., which is a far 

 superior and more expensive fertilizer. 



Again, it will be observed, that it produced a better result than 

 the superphosphate made by dissolving fine dust in sulphuric 

 acid, and costing at least 30s. more per ton. 



Plot XIII. Manured with 1^ cwt. of sulphate of ammonia : 



Produce .. 5 tons 6 cwt. 21 Ibs. 

 Decrease .. 1 ton 5 cwt. 2 qrs. 3 Ibs. 



The sulphate of ammonia used in this experiment was found to 

 consist in 100 parts of : 



Pure sulphate of ammonia . . 98'28 



Fixed salts y- * 78 



Moisture '94 



100-00 



The roots on this plot came up much later, and throughout 

 the whole experimental period were in a backward condition, 

 when compared with the rest of the field. 



The plants looked decidedly worse than those on the unmanured 

 portion. I mention, especially, that the swedes, contrary to 

 what I expected, had a less luxuriant foliage than even on the 

 unmanured plot. 



