273 



Of the 8ixty-five brands of nitrogenous superphosphates analyzed, twenty-two, or 

 more than one third, contain less of a single ingredient than is required by the man- 

 ufacturer's guarutee. In only seven cases is there a deficiency of the most valuable 

 ingredient, nitrogen, and in several cases the deficiency is in potash and due to a 

 form of guarantee which is misleading and in this State illegal. The manufacturer 

 is required to guarantee the actual potash. Potash, sulphate, 4 per cent, is under- 

 stood to mean 4 per cent of actual potash in the form of sulphate, aud not 2.16 per 

 cent of potash combined with 1.84 per cent of sulphuric acid. 



The average cash ton price of these sixty-five brands has been $33.74 ; the average 

 valuation, $28.14 ; the difference, $5.60; and the percentage difference, 19.9 per cent. 

 This means that in general the purchaser has paid about one fifth more per pound for 

 nitrogen, phosphoric acid, and potash when purchased ready mixed than he has had 

 to pay for the same elements of plant food unmixed. 



Special manures. — Of the thirty- three brands analyzed, ten contain less of a single 

 ingredient than is required by the manufacturer's minimum guarantee, and two others 

 are thus deficient in two ingredients. 



Eleven of the special manures are designed particularly for the potato crop. The 

 opinions of manufacturers, as well as those of farmers, would seem to differ widely 

 regarding the fertilizers best suited to this crop, for the per cent of nitrogen in the 

 several potato manures ranges from 2 to 5.3 per cent, the phosphoric acid from 7.7 

 to 11.2, and potash from 4.2 to 10 per cent. If applied according to the manufac- 

 turer's directions, the different potato manures would supply from 13 to 53 pounds of 

 nitrogen, from 52 to 100 pounds of phosphoric acid, and from 30 to 54 pounds of pot- 

 ash to the acre. Four of the formulas contain about a third of their nitrogen in the 

 form of nitrates, but four others contain no nitrates whatever. Two others contain 

 all but a fraction of 1 per cent of their nitrogen in the form of ammonia salts, bat 

 four others contain no ammonia. It is evident that while each of these several brands 

 may be an excellent general fertilizer, the claim that each or a majority of them is pre- 

 eminently adapted to the special needs of the potato crop would be absurd. 



Illinois station, Bulletin No. 11, August, 1890 (pp. 16). 



Experiments with wheat, T. F. Hunt, B. S. (pp. 337-352). 



Effect of fertilizers on wheat. — These experiments were made to test 

 the value of commercial fertilizers iu the production of wheat on Illinois 

 soils — to determine the relative increase where they were used, and to 

 study the forms of plant food most needed. A report is given of seven 

 trials made in 1888-89 and 1889-90, two trials being on the station 

 grounds and live on farms in diflerent localities in the State. Winter 

 wheat was used in all cases. The fertilizers were stable manure, 20 

 loads; cattle tankage, 400 pounds; superphosphate, 400 pounds; mu- 

 riate of potash, 100 pounds; sulphate of potash, 200 pounds; and nitrate 

 of soda, 100 pounds per acre. These were used singly, and in the 

 case of the potash salts, superphosphate, and nitrate, two by two and 

 all three together. They were applied in some cases at the time of 

 seeding, and in other cases part at the time of seeding and part (potash 

 salts and nitrate) to the young crop in the spring. On one unfertilized 

 plat a mulch of oat straw was used. The yields of wheat and straw 

 and per cent of increase over unfertilized plats are shown in tables and 

 a diagram. 



