87 



RED CLOVER grown year after year on rich Garden Soil, 

 Rothamsted Garden. 



Hay, Dry Matter, and Nitrogen per Acre, 1921 and 1922. 



WHEAT AFTER FALLOW (without Manure 1851, 



and since). 



Hogs Field, 1921 and 1922. 



AVERAGE WHEAT YIELDS of VARIOUS COUNTRIES 



NoTK.— Figures for Great Britain, England and Hertfordshire are taken from the Board of 

 Agriculture's "Agricultural Statistics," Vol. 46. Other figures from "Annuaire 

 International de Statistique Agricole," 1910-12, and converted at the rate of 60 lb. 

 per bushel. 



