PRACTICE XVII (CONTINUED) 



SOILS ... 



1 



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 



Per cent of humus 



Average per cent 



Tons of humus per acre 



Pounds of nitrogen per acre in humus 



37 



