COMMERCIAL FERTILIZERS 
7 1 
at an angle of about 45 degrees to the floor. The men 
stand on either side and shovel the fertilizer up on the 
screen. The finer particles fall through and the lumps 
roll to the bottom of the screen, where they can he 
crushed with the shovels. After the pile has been 
screened in this manner it is shoveled over twice. 
After mixing, the material should he rebagged in con- 
venient amounts. A common practice is to place 100 
pounds in each hag. A uniform amount in the hags is 
necessary to make an even distribution over the field 
before spreading or drilling. Mixing and rebagging 
should not cost more than 50 cents a ton. To prevent 
the forming of hard lumps the mixing should not he done 
more than a month before applying, especially if chem- 
icals are largely used, or 300 to 400 pounds of a good 
drier per ton may be used. 
Professor E. L. Worthen suggests that in order to 
avoid confusion in figuring formulas, some standard fer- 
tilizer mixture he taken as a basis, and varied as needed 
by increasing or decreasing a given constituent. He 
proposes the following basic mixture as a good general 
vegetable crop fertilizer: 200 pounds nitrate of soda, 200 
pounds sulphate of ammonia, 400 pounds 10 per cent 
animal tankage or dried ground fish scrap, 1000 pounds 
16 per cent acid phosphate, 200 pounds muriate of potash. 
The composition of the above mixture would be approxi- 
mately a 6-9-5, 011 the assumption that tankage or fish 
scrap contains the equivalent of 5 per cent available 
phosphoric acid. The amounts add up to an even ton. 
If it is desired to increase the potash content in propor- 
tion to the ammonia, an additional 100 pounds of muriate 
of potash may be added and the nitrate of soda reduced 
to 100 pounds. Thus a 5-9-7^ mixture would result. 
If a 5-10-5 formula is wanted, all that is necessary is to 
substitute 100 pounds of acid phosphate for the 100 
pounds of sulphate of ammonia in the basic mixture. 
