SOILS FERTILIZERS. 325 



at a profit, and phosphoric acid caused the largest average increase and was 

 used at the greatest average profit per acre. 



"In the wheat fertilization experiments the complete fertilizer gave the 

 largest average increase, and the greatest average profit per aci'e. In the 

 amounts used on wheat, each element was profitable, and they stood in the 

 same order of importance as in the corn fertilization experiments. The use of 

 200 lbs. of fertilizer per acre on wheat proved more profitable than the use of 

 100 lbs. per acre. 



"Phosphoric acid and potash gave a greater profit, per dollar invested in 

 fertilizer, than complete fertilizer, on both corn and wheat. Fertilizer gave a 

 greater average profit per acre on wheat than on corn, and was profitable in a 

 much larger percentage of the experiments. 



"Fertilization increased the jneld of oats about the same number of bushels 

 per acre as in the case of wheat. 



"In the potato fertilization experiments, complete fertilizer gave the greatest 

 average Increase, but the amount used was apparently too large to give the 

 greatest immediate profit. The formula used for potato fertilization, 4:8:10, 

 was found to be relatively too low in phosphoric acid content in proportion to 

 nitrogen and potash. In the amounts used for potato fertilization, nitrate of 

 soda was not as effective as dried blood. Muriate and sulphate of potash were 

 equally effective in increasing the yield, but in some cases sulphate produced 

 potatoes of better quality. 



"In the tomato fertilization experiments, complete fertilizer gave the largest 

 average increase and the largest average profit. It was more profitable to use 

 500 lbs. of fertilizer per acre on tomatoes than to use 250 lbs. per acre. 

 Nitrogen derived partly from nitrate of soda and partly from dried blood gave 

 better results on tomatoes than nitrogen derived wholly from dried blood, or 

 wholly from nitrate of soda. Fertilization of tomatoes in the hill gave better 

 results than broadcast fertilization. 



"The use of complete fertilizer gave better results on timothy than the use 

 of nitrate of soda alone, particularly the second year. 



"Nitrogen derived from peat was not as effective as nitrogen derived from 

 dried blood in any case. The purchase of nitrogen in large amounts for corn 

 and wheat fertilization did not prove profitable. 



"Heavy applications of fertilizer showed a lasting effect comparable to that 

 of manure. Rock phosphate did not give appreciable results until the second 

 3'ear after application. 



" In nearly all experiments with all crops on clay and loam soils phosphoric 

 acid was found to be the most effective of the fertilizer elements." 



The fixation of atmospheric nitrog'en by the use of aluminum nitrid, F. 

 Marre (G^nie Civil, 61 {1912), No. 2, pp. 30-33; Engrais, 27 {1912), No. 21, pp. 

 577-581; abs. in Chem. Abs., 6 (1912), No. 15, p. 2130).— The history, theory, 

 and the practical operation of this method of fixation of free nitrogen are dis- 

 cussed. The process is of special agricultural importance because of the high 

 nitrogen content (33 to 35 per cent) and cheapness of production of the nitrid. 

 Its direct action as a fertilizer has, however, not been fully investigated. 



On phosphoric acid fertilization and its importance in moor culture, H. 

 VON Feilitzen {Svenska Mosskulturfor. Tidskr., 26 {1912), No. 2, Sup., pp. 64, 

 figs. 30). — ^A treatise on the subject, based largely on the results of recent in- 

 vestigations and practical experiences in the cultivation of moor soils. The 

 results show the predominant need of phosphatic fertilizers on these soils. 



The fertilizing value of superphosphate, F. Klinkerfues {Zentbl. Kunsi- 

 diinger Indus., 16 {1911), p. 376; abs. in Chem. Ztg., 36 {1912), No. 4, Repert., 

 p. 19). — The changes which phosphate undergoes in the process of treatment 



