PRACTICE XVII (Continued) 



Pounds of nitrogen per acre in humus . 



Soils ^ 























j 1 





1 



2 



1 



2 1 



2 ! 1 



2 



Weight of crucible ! 















Weight of crucible and air-dry soil . . 















Weight of air-dry soil 









• 





Per cent of hygroscopic water (if needed) 













Weight of water-free soil (calculated) . 

















Weight of evaporated filtrate before 

 ignition 















Weight of evaporated filtrate after 

 ignition 

















Loss in weight = humus (approximately) 



















Total humus of sample 









j 









Per cent of humus 



















Average per cent ...;.... 











Tons of humus per acre . . . . . . 







j 

 i 



37 



