880 



Manures in December. 



[Dec. 



of organic fertilisers, and anything that would help to increase 

 the supplies would be welcomed. Attention may be directed 

 to the experiment carried out at the Woburn Station, where 

 ground leather powder was applied on swedes at the rate of 

 1 ton per acre to one plot, while another received 1 ton per 

 acre of leather treated with sulphuric acid so as to make the 

 nitrogen soluble; a third plot received a dressing of sulphate of 

 ammonia supplying as much nitrogen as was in the leather. 

 Sulphate of ammonia produced its full effect, but the leather 

 had no action at all. 



Comparison of Bone Meal with Slag. — An interesting 

 experiment has been in progress for some years at Cockle Park, 

 to test the comparative values of bone meal and basic slag on 

 hay land. The results are: — 





i A.verage 



Hay Per Aero. 



Value of 

 Increase at 

 5U/- per 

 ton. 





Plot. 



Treatment per Acre. Feb.. 

 1908. Redressed Dec. 19 in. 

 Dec. 1916. and Dec, 1919. 



Annual 

 Cost of 

 Treat- 

 ment. 



1919. 



Average of 

 12 Years. 



Average 

 Increase 

 over Plot 1. 



Average 

 Annual 

 Gain. 







S. (1. 



Cirt. 



rwt. 



eirf. 



S. d. 



d. 



1 



(To the west) Xo 

















treatment ... 







"•2 









2 



10 cwt. High Grade 

 Basic Slag. 39-32% 



Phosphates (2U0 lb. 

















Phosphoric Acid) ... 



S 



13.' 



22f 





38 1 



31 5 



8 



14 cwt. Medium 

















Grade Basic Slag, 

















27-39% Phosphates 

















(200 lb. Phosphoric 

















Acid) 



9 1 







u 



35 



25 8 



i 



19| cwt. Low Grade 

 Basic Slag, i9-827„ 



Phosphates (200 lb. 

















Phosphoric Acid) ... 



10 8 





191 



12 



.30 (> 



19 1 





8| cwt. Bone Meal, 

















4.5-097o Phosphates 

















(200 lb. Phosphoric 

















Acid) 



18 8 



13 



20| 



m 



31 11 



13 3 



Bone meal is shovv^n to have given a marked increase in yield 

 over the unmanured plot, but it is no better than medium 

 grade slag and not so good as high grade slag. The financial 

 return from bone meal has been less than from any of the slags 

 and less than half from the best slag plot. 



Value of the Solubility of Basic Slag. — Mr. Scott Eobertson 

 has recently summarised the results obtained by the use of the 

 various slags and mineral phosphates in Essex. His results 

 throw considerable light on the important question as to 

 whether the farmer is justified in paying extra prices for high 

 soluble slags. The crop returns show that high grade slag is, 

 as a matter of fact, rather better than low grade, especially in 



