131 



A limit of four years was decided on by Yoelcker and Hall, 

 after a full review of evidence that any manures applied to a 

 first crop of a four years' rotation are, as a rule, nearly ex- 

 hausted by that time. They also came to the conclusion that 

 the unexhausted value should decrease by one-half each year, 

 as the earlier crops of the rotation receive the greatest benefit 

 from the manurial constituents applied to the first crop. The 

 elaborate rotation experiments made by this College fully bear 

 out these conclusions. (See College Bulletin No. 4.) 



TABLE C. MANURIAL VALUE OF FEEDING STUFFS. 



(Extracted from article by Voelcker and Hall in Journal of Royal Agricultural 



Society, 1902.) 



* The figures given above apply to Egyptian cotton cake. Indian (Bombay) cotton cake 

 contains rather less nitrogen, and its full manurial value is only 31/- per ton. 



