166 EXPERIMENTS UPON GRASS LAND 



Cwt.perAc 

 60 



Plots 3&I2 



Fig. 28.— Effect of Nitrogenous Manures on the produce of Hay per acre. Average 

 over 47 years (1856-1902). 



Plots 3 and 12. Unmanured. 



Plot 7. Complete Mineral Manure, no Nitrogen. 

 Plot 9. Do. and Amm.-salts = 86 1b. N. 



Plot 11. Do. do. =129 lb. N. 



Plot 16. Do. and Nitrate of Soda = 43 lb. N. 



Plot 14. Do. do. =86 lb. N. 



