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Report of the Chemist of the 



one fourth the amount applied, and only 9 pounds more than was 

 removed when no phosphoric acid was added. 



(6) We will assume that at the beginning of the two years the 

 soil contained not less than 26.4 pounds of available phosphoric 

 acid. Adding this to the applied amounts we can prepare the 

 following tabulated statement: 



While the data do not probably express the complete truth 

 regarding the amount of available phosphoric acid in the unfer- 

 tilized soil, it is the fertilized soil to which our attention here is 

 called. When we applied 1,000 pounds of fertilizer, we had in 

 the soil nearly six times as much as the first crop used. At the 

 beginning of the second year there was remaining about six times 

 as much as the second crop actually used, and at the end of two 

 years twice as much phosphoric acid still remained unused as 

 had been used by two crops. When an application was made of 

 2,000 pounds of fertilizer an acre, there was present for the use of 

 the crop about ten times as much as was used by the first crop. 

 There was left for the second crop ten times as much as it used, 

 and after the removal of two crops there remained over four 

 times as much phosphoric acid as had been used by two whole 

 crops. The amount of phosphoric acid furnished by the average 

 potato-fertilizer found in the market would, from these consid- 

 erations, be regarded as containing phosphoric acid in excessive 

 amounts as compared with the actual needs of the crop. 



