FERTILIZEKS. 839 



FERTILIZERS. 



The influence of the distribution of fertilizers on their action, 



J. M. PoMOKSKi {ZtscJir. Landw. Yersuchato. Ocderr.^ 3 {lOUO), Xo. 7, 

 pp. G.'^-G8Jf.^ ph. S). — Field and pot experiments with oats, barle}', and 

 celeiT are reported in which fertilizers (superphosphate, Thomas slag, 

 nitrate of soda, sulphate of ammonia, and kainit) were applied (1) as top 

 dressing, (2) in furrows and rows, (3) mixed with the whole of the sur- 

 face soil, and (-t) at diflerent depths in the soil. The results show that 

 the yield was influenced not only by the kind and amount but also by the 

 distril)ution of fertilizers. The influence varies with the kind of plant 

 and fertilizer and depends upon the character of the root system, the 

 special fertilizer requirements of the plant, and the manner in which it 

 takes up its food. It is therefore of great practical importance not only 

 to determine the relative efl'ectiveness of the diflerent fertilizers for each 

 soil, but also the method of application which will give the best results, 

 taking into account at the same time the influence of supplementary 

 fertilizers in modifying the action of the principal fertilizing ingredi- 

 ents required by the soil. It was found, for instance, in the experi- 

 ments reported, that superphosphate in small amounts in the upper 

 layers of the soil interfered with the action of nitrogen in sulphate of 

 ammonia. In other words, the action of sulphate of ammonia was 

 dependent upon the distribution of the other fertilizer in the soil. All 

 fertilizers gave better results when mixed with the soil than when 

 applied in layers. 



Field experiments with phosphoric acid in various forms, F. W. 

 Dafert and O. Keitjmair {Feldungungsversuche iiht-r die Wirlung der 

 PJiospJiorsailre in verschiedenen Formen. Vienna: Landvnrthschaftlich- 

 chemischen Versuchsstaticm^ 1900^ pp). 23). — Field experiments with 

 diflerent samples of Thomas slag, superphosphate, Algerian phos- 

 phate, and degelatinized bone meal are reported. The phosphoric 

 acid of Thomas slag, having a high citrate solubility, was no more 

 eft'ective on either summer or winter grain than that of slag having- a 

 low citrate solubility, the value of the slag being determined by its 

 total phosphoric acid content. The purchase of slag on its citrate- 

 solubility is condemned on both scientitic and practical grounds. The 

 degelatinized ])one meal gave good results with summer grain. The 

 author therefore concludes that the results of pot experiments which 

 indicate that the phosporic acid of bone meal is of no value are unre- 

 liable. Algerian phosphate appeared to be of equal value with 

 Thomas slag for summer grain. The relative effectiveness of the 

 phosphoric acid in Thomas slag and in superphosphate was as 70 to 

 100 in experiments with oats and barley. The effectiveness of the 

 phosphoric acid in Algerian phosphate and bone meal was very nearly 

 the same as that of the phosphoric acid of Thomas slag. The relative 



