WHEAT 



33 



riot 9 has the same manuring as Plot 6, and Plot 16 as Plot 7, except 

 that the ammonium-salts on Plots 6 and 7 are replaced by ocjuivalent 

 amounts of nitrogen as nitrate of soda. The manuring of Plots 9 and 

 16 has, however, been changed during the progress of tlie experiments, 

 so that they are only comparable with 6 and 7 since 1885. Taking a 

 recent ten year average, as set out in the diagram. Fig. 9, it will be seen that 

 nitrate of soda is a more effective source of nitrogen than the ammonium- 



Total Produce 

 perAcr« 



6000 lb. ^— ' ■ 



SGIb.N. 



after Minerals only 



in PreviousYear. 



Straw per Acre ,1b. 



Grain per Acre, lb , 



Fig. 10.— Comparative Effects on Wheat of Ammonium-salts applied at different times. 

 Averages— Plots 5, 17, and 18, 51 years (1852-1902). 

 Plots 7 and 15, 25 years only (1878-1902). 

 The figures in the labels indicate bushels of Grain and cwt. of Straw. 



C 



