622 EXPERIMENT STATION RECORD. 



tion of nitrogenous niatei'ial in fertile soil and sand, including ammonia produc- 

 tion in the soil from different amounts of peptone, from dried blood, and from 

 A'arying amounts of peptone, dried blood, and cotton-seed meal in varying quan- 

 tities of soil both with and without a constant bacterial content ; ammonia pro- 

 duction fi-om peptone and dried blood in constant quantities of soil with a vary- 

 ing bacterial content ; the chemical and bacteriological factors in the ammoui- 

 flcation and nitrification of nitrogenous materials in the soil ; the effects of 

 soluble and insoluble carbohydrates, such as dextrose, starch, and filter paper, 

 on ammonia formation In soils and culture solutions ; ammonia formation by 

 BaclUus mycoides as affected by the presence of dextrose; comparative tests on 

 the ammonification and nitrification of nitrogenous materials; nitrate forma- 

 tion as affected by soil volume; and the effect of additions of nitrates on the 

 accumulation of nitrates in the soil. 



It seems that the carbon-nitrogen ratio is of moment in the rate of ammoni- 

 fication of nitrogenous materials, and that the modification of this ratio by 

 soluble carbohydrates or by other soluble carbon compounds may lead to changes 

 in the numbers and species of the micro-organisms in the soil or culture solu- 

 tions and a consequent depressed or intensified ammonification depending on 

 the character of the nitrogenous fertilizers. 



The relative availability of nitrogenous materials as shown by nitrate forma- 

 tion depends to a considerable extent on their distribution, or the ratio of the 

 soil volume to that of the substance to be nitrified ; that is to say, a nitrogenous 

 fertilizer that is evenly distributed in the soil and scattered through a large 

 amount of it will undergo ammonification and nitrification more rapidly and 

 more uniformly than a similar material not properly distributed. 



Periodicity in the accumulation of nitrates in the soil may be due to the 

 temporary prominence of species especially capable of transforming large 

 amounts of nitrate into protein nitrogen, as well as to a more rapid increase of 

 various decay organisms and their intense utilization of nitrates for the building 

 of their bodies. 



The decomposition of cyanamids through the action of fungi, H. Kappen 

 {Centbl. Bdkt. [etc.], 2. Aht., 26 {1910), 'No. 20-2J,, pp. 633-6JiS).—ln a series 

 of experiments with fungi to determine their ability to decompose cyanamid, 

 five fungi were found to possess this power, a Cladosporium, PeniciUium brevi- 

 caule, a green PeniciUium, a rose-colored fungus, and Sfysdnus stemonitis. 



Of these, the Cladosporium and the green PeniciUium were able to thrive in 

 a i per cent solution of the cyanamid and to decompose it, while the other 

 three were unable to grow in a solution of cyanamid greater than 1 per cent. 



From the nature of the decomposition products it is claimed that the enzym 

 of the cyanamid decomposition is not identical with urease, and also that 

 fccto-enzyms play no part in the decomposition. The experiments also indicated 

 that the growth of micro-organisms in a lime nitrogen solution is impossible as 

 long as the lime content is sufficiently high. 



The role that fungi play in the decomposition of lime nitrogen in cultivated 

 soils can not be definitely settled until the ability of soil bacteria to decompose 

 cyanamids is further tested. 



Excessive fixation of nitrogen in some alkaline soils of Colorado, W. P. 

 Headden {Proc. .S'oe. Prom. Agr. Sci., 30 {1909), pp. 62-69). — This is a brief 

 account of investigations which have already been noted (E. S. R., 23, p. 221). 



Experiments with nitric acid on alkaline soils, R. S. Symmonds {Agr. Gaz. 

 N. S. Wales, 21 {1910), No. 3, pp. 257-266, figs. 11).— The experiments here 

 reported conclude a series of field tests in the Coonamble District of New South 

 Wales, in which nitric acid at the rate of OOi) lbs. per acre was mixed with 

 artesian well water and sprinkled on the soil with a view to correcting its alku- 



