726 EXPERIMENT STATION RECORD. [Vol. 36 



plied in the form of acid phosphate. Such soils have the capacity for fixing 

 considerable potash, but this power is soon exhausted, and afterwards rela- 

 tively large amounts of potash are lost through leaching." 



[Use of manures in Germany], T. H. Middleton (In The Recent Develop- 

 ment of Oerman Agriculture. London: Bd. Agr. a/nd Fisheries, 1916, pp. 36, 

 37). — It is stated that " the chief immediate cause of the increased productivity 

 of German soil is the increase in the use of artificial manures." Between 1890 

 and 1910 the total consumption of artificial fertilizers in Germany is stated to 

 have risen from 1,600,000 to 6,000,000 metric tons. There was a tenfold increase 

 in the use of potash and a threefold increase in the use of basic slag. 



" The chief factor in developing the use of artificial manures in Germany was 

 unquestionably a well-organized system of technical education. Investigation 

 at the research stations established the precise uses of these manures; trust- 

 worthy advice was supplied by institutions, by peripatetic instructors, by tech- 

 nical leaflets, and by agricultural newspapers," and the farmer, even the back- 

 ward peasant, brought his method into line with the instruction so given. 



It is pointed out that Germany has the advantage not only of great deposits 

 of potash salt but vast tracts of light soils specially benefited by potash manures, 

 and hence very successful results have been secured from the intelligent use of 

 such manures. 



Some effects of soluble humus on the growth of plants, W. B. Bottomley 

 (Assoc. Franc Avanc. Soi., Compt. Rend., IfS (19U), pp. 969, 970).— This is a 

 summary of a number of experiments made by the author with bacterized peat. 



A vegetation experiment on the availability of nitrogenous fertilizers in 

 an arid soil, C. B. Lipman and W. F. Gericke (Soil Sci., 2 (1916), No. 6, pp. 

 575-581). — Vegetation experiments with barley on an arid .'sandy soil are re- 

 ported which showed " the low-grade organic nitrogenous fertilizers and sul- 

 phate of ammonia to be far more available than dried blood. This confirms 

 the values as to relative availabilities of these fertilizers obtained by laboratory 

 nitrification method. Nitrates, and especially nitrate of calcium, are far less 

 available in the soil than are the other fertilizers with the exception of dried 

 blood, which is about equal to nitrate of soda but superior to nitrate of calcium. 



" These data furnish further evidence in support of the proposal to adopt the 

 nitrification method in some form for the determination of the relative avail- 

 abilities of fertilizer and soil nitrogen and for determining the needs of a soil 

 for available nitrogen." 



A list of references to literature on the subject is given. 



Ammonifiability versus nitrifiability as a test for the relative availability 

 of nitrogenous fertilizers, C. B. Lipman and P. S. Burgess (Soil Sci., 3 (1917), 

 No. 1, pp. 68-75). — Araraonification and nitrification experiments with 22 soils, 

 principally arid, and tested with dried blood, high-grade tankage, steamed bone 

 meal, cottonseed meal, and fish guano, are reported. "The ammonifiability 

 data gave the fertilizers in question the reverse position as to availability 

 from those given them by the nitrifiability data." 



It is concluded that " the ammonifiability data of fertilizer nitrogen in soils 

 are not useful indicators of the nitrifiability data on the same fertilizers in the 

 same soils. . . . The nitrifiability of a given form of nitrogen should be the 

 most reliable laboratory criterion which we can employ. The laboratory results 

 are now being confirmed by vegetation experiments. Hence there appears to 

 be no reason against adopting nitrifiability as the criterion of availability of 

 nitrogenous fertilizers, for purposes of arid soil conditions at least." 



Eight references to literature bearing on the subject are appended. 



Technological-chemical research on superphosphates, U. Pratolongo (Ann. 

 Chim. Appl. [Rome], 6 (1916), No. 3-4, pp. 59-112, figs. 4; abs. in Jour. Soc. 



