76 



Notes on Manures for April, 



[Apr., 



The crop yields are : — 





Barley, 1919. 



Sicedes, 1920. 





1921. 





Grain 





Roots 



Grain 



Straw 





hush. 



Clljt. 



tons. 



bush. 



CLOt. 



■Complete artificials only: — 













including Basic Slag 



31-2 



17-4 



... 15-8 ... 



34-1 



20-1 



Superphosphate 



23-9 



16-3 



... 16-3 ... 



33-5 



17-8 



Guano 



24-3 



17-0 



... 14-4 ... 



27-9 



171 



Eape dust ... 



22-4 



13-5 



... 13-3 ... 



361 



17-3 



Shoddy 



23-3 



14-5 



... 11-9 ... 



30-8 



16-0 



Bone meal ... ... .... 



23-2 



14-6 



8-6 ... 



24-1 



141 



In each case the dressing contains 40 lb. of nitrogen, 100 lb. 

 of calcium phosphate and 50 lb. of potash per acre. Each plot 

 was supplied with as much of its particular m.anure as possible 

 (shoddy, guano, etc.) without exceeding the receipt in any of 

 the three rationed itigxedients. Any deficit in any one of these 

 tkree was made good by adding the necessary quantity of 

 sulphate of ammonia, superphosphate or sulphate of potash. 



Manuring for a dotation: How long v^^ill it last? — The 

 manures ordinarily in use do not deteriorate in the soil but 

 they suffer loss in tw^o w^ays : (a) all fertilisers are taken up by 

 the crop and bodily removed from the soil; (b) the nitrogenous 

 manures are liable to be washed out from the soil, but the 

 potash and phosphate are not. It has been shown on an earlier 

 occasion that a moderate sized cereal crop removes from the soil 

 the equivalent of 3 cwt. of sulphate of ammonia, IJ cwt. of 

 superphosphate and | cwt. of sulphate of potash per acre; a 

 12-ton crop of potatoes removes the equivalent of 4 cwt. sulphate 

 of ammonia, 3 cwt. of superphosphate and 2J cwt. of sulphate of 

 potash; and a 30-ton mangold crop the equivalent of 5 cwt. of 

 sulphate of ammonia, 3 cwt. of superphosphate and 5 cwt. of 

 sulphate of potash. It is only when the- total dressing of dung 

 and artificials exceeds these amounts that any effect can be 

 expected in the second year. 



Bone Meal and Dissolved Bones: Are they useful on Grass 

 Land? — In the past great results were obtained by the use of 

 bone manures on grass land in Cheshire, and a considerable 

 reputation was gained for these substances. It is, however, 

 doubtful whether they really deserve to stand very high in 

 esf-ppm for this purpose. In the Cockle Park experiments they 

 certainly were not as useful as slag on grazing land, as tHey 

 did not encourasje the white clover to anything like the same 

 extent. A number of trials organised by the Royal AgTicultural 

 Society and reported by Dr. J. A. Voelcker and Professor 

 €arruthers in 1900 (Journ. Royal Agric. Soc, 1900, 

 Vol. LXI. 116) were quite unfavourable. 



