lolG] SOILS FERTILIZERS. 215 



be possilbe to bring fruit and flowers to maturity earlier than can be done by 

 other means." 



Considerable space is devoted to the newly discovered accessory food bodies 

 or auximones in bacterized peat. A number of different experiments are re- 

 ported, the results of which are taken to indicate " conclusively that bacterized 

 peat contains a substance or substances which stimulate the growth of the plant 

 and enable it to utilize the normal food constituents supplied to it. In nature 

 the need is doubtless supplied by the decaying organic matter in the soil." 



Bacterial activities and crop production, P. E. Beown (Iowa Sta. Research 

 Bui. 25 {1915), pp. 359-S88) .—The substance of this bulletin has been previously 

 noted from another source (E. S. R., 34, p. 619). 



The reclamation of bog land {Dept. Agr. and Tech. Instr. Ireland Jour., 

 16 (1916), No. 2. pp. 229-236, pis. 10).— A number of pot and field experiments 

 conducted for three years with different common crops on Irish bogs are re- 

 ported, the results of which are taken to indicate that lime is the limiting factor 

 in the reclamation of Irish bogs while phosphate is next in importance. 



" Notwithstanding the large amount of nitrogen in the peat, the necessity of 

 supplying this ingredient in a form in which the plant can use it was clearly 

 demonstrated. ... As long as the different crops were producing leaf and stem 

 only, potash was the least important of the four ingredients, but its influence 

 was most marked in filling the grain and stiffening the straw in the case of the 

 rye and of increasing the yield of tubers in the case of the potato." 



An experiment with marls and shell sands as substitutes for lime on these 

 soils showed that most of the marls and shells tested were as good as burned 

 lime. 



Analysis of plants and soils to determine the amounts of nutritive sub- 

 stances in soils, T. Pfeiffer, E. Blanck, W. Simmebmachek, and W. Rath- 

 MANN (Landw. Vers. Stat., 86 {1915), No. 5-6, pp. 339-S91; abs. in Cliem. 

 Zenthl., 1915, II, No. 5, pp. 239, 2JfO ; Ztsehr. Angew. Cherri., 28 {1915), No. 65, 

 Referatenteil, p. J,21; Jour. Chem. Soc. [London], 108 {1915), No. 63^, I, pp. 163, 

 764; Jour. Sue. Chem. Indus., 34 {1915), No. 18, p. 972).— Pot and laboratory 

 experiments with seven different soils to determine the usefulness of plant and 

 soil analysis in estimating the fertilizer needs of soils are reported, being based 

 in part on the results of previous work (E. S. R., 29, p. 514). 



The conclusion is drawn that in establishing uniformity in the available water 

 content of different soils, the content of hygroscopic water represents the water 

 content at which plant growth starts only in so far as with increasing hygro- 

 scopicity of the soils a corresponding water addition is necessary. On this 

 basis, crop substances were obtained on different soils which showed only a 

 slight variation in the content of the nutritive constituent present in minimum, 

 or the so-called normal content. This is taken to indicate that the physical 

 properties of soil are not of great importance in plant production in so far as 

 they do not influence the factor water. It is concluded further that the so-called 

 normal content of any nutritive constituent does not offer a sufficient compara- 

 tive basis on which to interpret plant analysis in terms of fertilizer needs of 

 the soil. 



It was further found that the amount of nitrogen taken up by plants from 

 an unmanured soil was only slightly increased by manuring with an excess 

 of phosphoric acid and potassium. Assimilation of phosphoric acid, on the other 

 hand, was much more influenced by application of nitrogen and potassium, 

 partly owing to greater root development and partly to increased solubility 

 of the soil phosphates, which varied with different soils. The same held good in 

 the case of potassium. 



