INSPECTION OF COMMERCIAL FERTILIZERS 



Ten of the most popular grades are listed in the following table in the order 

 of largest tonnage and in comparison with a similar list for 1931. 



The adoption of whole numbers in expressing fertilizer grade no doubt 

 made it somewhat more difficult for many users to make their final selection 

 in 1932, thus requiring greater effort on the part of the fertilizer salesman. 

 This may be illustrated by a study of the 5-8-7 grade. 



In 1931, 5-8-7 meant 5 per cent ammonia (4.11 per cent nitrogen), 8 per 

 cent available phosphoric acid, and 7 per cent potash; while in 1932, it meant 

 5 per cent nitrogen, 8 per cent available phosphoric acid, and 7 per cent potash. 

 The tonnage of 5-8-7 was 2,115 less in 1932 than in 1931, many users selecting 

 the 4-8-7 grade, which is more nearly like the 5-8-7 grade of 1931 in analysis, 

 and of which 4,475 tons were sold. However, the tonnage of 5-8-7 sold in 

 1932 would indicate that many users are convinced that the higher percentage 

 of nitrogen (.89': c) is good economy. The combined tonnage of 5-8-7 and 

 4-8-7 for 1932 was 14,281 which was 2,360 tons more than the tonnage of 

 5-8-7 in 1931. 



Similarly, while the 1932 tonnage of the 4-8-4 grade was less than the 

 tonnage of this grade in 1931, the combined tonnage of 4-8-4 and 3-8-4 in 

 1932 was 42 tons greater than that of the 4-8-4 grade in the previous year. 

 It would seem to the writer that with continued low cost of nitrogen, the 

 tonnage of the higher nitrogen grade in each case will gradually increase. 

 It is doubtful economy to maintain indefinitely two fertilizer grades, the 

 limit of variation of which is only 1 per cent of nitrogen when this difference 

 is not measurable or justifiable in terms of crop response. 



The 3.29 (4)-6-10 grade, which had the third largest tonnage in 1931, has 

 been replaced by the 4-8-10, which had the fourth largest tonnage in 1932. 

 The 2.47 (3)-8-4 grade, with the fourth largest tonnage in 1931, has been 

 largely replaced by the 3-10-4, which had the fifth largest tonnage in 1932. 

 The 4-10-5 grade, which in 1931 was expressed 4.11 (5)-10-5, was advanced 

 from the ninth to the seventh place in the tonnage sold. The 7-6-6 grade, 

 which in 1931 was expressed 6.58 (8)-6-6, advanced from the seventh to the 

 sixth place, with a tonnage increase of 268. The 5-3-5 grade, 4.11 (5)-3-5 

 the previous year, occupies the tenth place in 1932, with a tonnage decrease 

 from the previous year of 752. Two other grades of tobacco fertilizer, 5.76 

 (7)-3-7 and 4.94 (6)-3-6, which occupied sixth and tenth place in the tonnage 

 sold in 1931, now occupy the fourth-ninth and eleventh place, respectively. 



