95 



Acid Pjiospiiati-, Vkhsus Raw Phosphate 

 111 Tabic III is found a comparison of the effect of 

 iicid i)lios|)lialc' and raw phospliatc (finely ground un- 

 treated phosphate rock) on the production of soy bean 

 seed. The experiment was conducted on a strong red 

 soil. The plots received the same amount of fertilizer 

 in the fall when they were planted in oats. When the 

 oats were Jiai'vested in the spring, the land was plowed 

 ^nd fertilized again at the rate indicated in the tables 

 and planted in soy beans. The low yield of beans is 

 largely due to [\\c late j^lanting. 



Table III. — Tlie Yield of Soy Bean Seed Per Acre from 

 the Use of Acid Phosphate and Raw Phosphate 



Rate per 

 acre 





a 



<.t: 



Acid Pliosphate 

 320 lbs. 



Raw Phosphate 

 :V20 lbs. 



No Pliosphate - 



Bu. 



.8 

 1.7 



From the application of 320 pounds of acid phos- 

 phate per acre, the average gain was only .8 bushels, 

 and from the same amount of rock phosphate the 

 average gain was 1.7 bushels. 



Taijle IV. — The Yield of Soy Bean Hay Per Acre from 

 the Use of Acid Phosphate and Raw Phosphate 



Rate per 

 acre 



a 



a< 



The yield of hay as a result of fertilizing with acid 

 phosphate and rock pliosj)Iiate is shown in Table IV. 

 This experiment was conducted on the same land and 

 followed the same plan as that reported in Table III. 



The average increase from the use of 320 pounds of 

 acid phosphate per acre was 323 pounds of hay* and 



