THE PRINCIPLES OF FERTILIZER PRACTICE 487 



the materials are to be applied separately, the rate to the acre 

 and the number of acres must be known. If a mixture is to be 

 made, the formula of this mixture must be decided on in addi- 

 tion. The pounds of the various carriers necessary to produce 

 a given amount of a certain mixture can now be calculated. 

 All of this is a matter of good judgement and careful arith- 

 metic. 1 



With the separate carriers at hand, the mixing, if necessary, 

 is quickly accomplished. All that is needed may be listed 

 as follows: (1) a tight floor, (2) a coarse sand screen, (3) a 

 tamper or grinder, and (4) shovels, a rake, and like tools. 

 Since the pounds of fertilizer are quoted on each bag, weigh- 

 ing is unnecessary in making up a given amount of a mixture 

 having a certain formula. Bags may be divided into half or 

 quartered with sufficient accuracy. 



The bulkiest material is spread on the floor first and leveled 

 uniformly by raking. The remaining ingredients are then 

 spread in thin layers above the first, in the order of their bulk. 

 Beginning at one side, the material is next shoveled over, care 

 being taken that the shovel reaches the bottom of the pile each 

 time. The pile is then again leveled, and the process is re- 

 peated a sufficient number of times to insure thorough mixing. 

 Sometimes a mixing machine may be used for this operation. 

 For storage and general convenience, the fertilizer may be 

 weighed into sacks of 100 to 150 pounds capacity and put in a 



240 pounds of tankage. 

 100 pounds of dried blood. 

 1250 pounds of acid phosphate (16%P 2 5 ). 

 160 pounds of muriate of potash. 



*A 2-8-2 fertilizer is to be compounded from dried blood containing 

 12% NH 3 , acid phosphate carrying 14% P 2 5 and kainit containing 

 12% K 2 0. In one ton of the mixture there should be 40 pounds of NH 3 , 

 160 pounds of P 2 5 , and 40 pounds of K 2 0. 



40 -f- ,12 = 333 lbs. of dried blood. 

 160-^.14=1142 lbs. of acid phosphate. 

 40-l-.12= 333 lbs. of kainit. 

 192 lbs. of filler. 



2000 lbs. total. 



