ELEMENTS OF PLANT FOOD 



33 



No treatment 



2590 lbs. hay per acre 



640 lbs. nitrate soda 

 320 lbs. acid phosphate 

 80 lbs. muriate potash 

 7590 lbs. hay per acre 



320 lbs. nitrate soda 

 320 lbs. acid phosphate 

 80 lbs. muriate potash 

 7110 lbs. hay per acre 



Figure 8. — Plenty of nitrogen is essential to good hay crops. The 

 function that nitrogen performs is that of constituting a basic element of pro- 

 tein, which is an important food factor. Those crops, therefore, that have 

 prominent protein values require an adequate amount of nitrogen for the con- 

 struction of leaves, stems, and grain. Nitrogen is particularly beneficial to 

 which suffer less from its excess than cereals. 



3— 



20 tons manure lU tons manure N o treatment 



7420 lbs. hay per acre 4350 lbs. hay per acre 2230 lbs. hay per acre 



Figure 9. — Grass makes better use of barnyard manure than any other crop. 



