BARLEY 



37 



genous manures. The mineral manuring on the strips is as follows: — 

 (1) None ; (2) Phosphoric acid only, no potash or alkali salts ; (3) Potash, 

 magnesia, and soda, no phosphoric acid ; and (4) Complete mineral 

 manure, supplying both phosphoric acid and the alkaline salts. Each of 



these is combined with the four cross-dressings of nitrogenous manures 



Series O, no nitrogen ; Series A, ammonium-salts ; Series AA, nitrate of 

 soda ; Series AAS as Series AA and silicate of soda in addition ; and 

 Series C, rape cake. There are other plots, one of which received farm- 

 yard manure for the first twenty years, but has since been unmanured. 



Table XYIU.—Exjyeriments on Barley, Hoos Field. Produce of Grain and Straiv 

 per acre. Averages over 60 years (1852-1911), aTuZ over 10 (1902-1911). Also 

 Produce in 1911 . 



* 48 years (1864-1911). 



t 40 years (1872-1911). 



Effect of Nitrogenous Manures. 



The effect of nitrogenous manures upon the barley crop is best seen by 



various Plots 4, all of which receive the same 



comparing the yields of the 

 mineral manures ; the diagram 

 graphic form. 



Fig. 



11, shows this 



same 

 comparison in a 



C 2 



