64 THE MANURING OF GRASS LAND [CH. 



worth only about 2s. 6d. per acre. Part of Tree Field then 

 received 10 cwts per acre of basic slag and nothing more ; it was 

 grazed with sheep which received no cake or meal, and the increase 

 in live weight was noted. On another part of the land the sheep 

 received decorticated cotton cake for the first year, but no 

 fertiliser was applied to the land : in 1903 and 1904, cake was also 

 fed. After the experiment had continued for 9 years, the first 

 plot received a further dressing of slag (10 cwts per acre). The 

 live weight increases in the sheep, reckoned as Ibs per acre per 

 annum, were as follows 1 : 



No cake 



Decorticated Basic slag 



No cake cake* (10 cwts in 



No manure No manure 1897 and 1905) 



Plot 6 Plot 1 Plot 3 



1st 9 years, 1897-1905 ... 37 106-7 117 



Increase due to manuring 69-5 80 



2nd 6 years, 1906-1911 ... 23 42-5 117 



Increase due to manuring 19-5 94 



* 597 Ibs cake per acre in 1897-8, in 1903 and in 1904. 



The plots are shown in Fig. 15. 



The cake gave good results in the years when it was fed, but 

 not afterwards. Similar but larger increases in live weight were 

 obtained in the Hanging Leaves Fields where cattle and sheep 

 have grazed together, the mixing of animals being good for the 

 pasture; considerable stress is laid on this. 



The experiment was repeated at Cransley, in Northampton- 

 shire, on a poor wet boulder clay. Over a three year period one 

 dressing of 10 cwts of basic slag gave just as much live weight 

 increase in the sheep set to graze the pasture as 1 Ib of decorti- 

 cated cotton cake per head per day for the first two years 13 J 

 cwts per acre in all. (Fig. 16.) And, moreover, the improve- 

 ment made by slag lasted, while that made by cake did not. 

 Similar results were obtained at Hatley in Cambridgeshire, and at 

 Yeldham in Essex 2 . 



After the improvement by slag it is essential to graze the land 

 well. Cake can now be fed if desired, and further dressings of 

 slag periodically given. 



1 Cockle Park Bull. No. 7, 1906, and No. 19, 1913. 



2 See Cambridge Reports, Guide to Experiments, 1905. 



