128 EXPERIMENT STATION HKCOIM). 



Th.e loss of nitrogen in the storage of calcium cyauamid, I. V. Yakusiikin 

 (Izv. Moskov. Selslc. Ehoz. Inst. [Ann. Inst. Ayron. Moscoti], 15 (1909), No. 2, 

 pp. 166-176, dgm. 1). — The experiments reported show that the loss of nitrogen 

 in the storage of calcium cyanamid varies widely with atmospheric conditions. 

 AVhen the air was humid and the cyanamid was spread out in thin layers large 

 losses (as mucli as GG per cent of the total nitrogen in 7 to 8 months) were 

 observed. On the other hand, 10 kg. of cyanamid Icept in a sack in a moderately 

 dry atmosphere lost only 10 per cent of tlie total nitrogen in 2 years, and in 

 very dry air the loss was still smaller. No ammonia was observed when the 

 cyanamid was kept under a cover glass over sulphuric acid. 



Dicyandiamid, I. V. Yakushkin (Izv. Moskov. Selsk. Khoz. Inst. [Ann. Inst. 

 Agron. Moscou], 15 (1909), No. 2, pp. 177-192). — An attempt is made to con- 

 struct a formula for this substance on the basis of results obtained by the action 

 of nitrons acid on the dicyandiamid. 



Potash silicate, J. Barcia y Trelles (Prof/. Agr. >/ Peeuario, 15 (1909), No. 

 63J/, pp. 399-JfOl). — A complete analysis of the commercial product sold as a 

 fertilizer is reported, as well as studies of the solubility of the potash in differ- 

 ent solvents. 



Sand cultures with various potash minerals, A. G. Doyarenko (Izv. Moskov. 

 t^elsk. Khoz. Inst. [Ann. Inst. Agron. Moscow], 15 (1909), No. 1, pp. 7//-88, 

 figs. 8). — In the series of experiments reported it was found as a rule that 

 orthoclase was a very poor source of potash for plants, while potash mica gave 

 better results. The best i-esults, however, were obtained with a stone contain- 

 ing nepheline, with which one-third of the potash present was assimilated by 

 plants. The results with orthoclase varied very slightly from those obtained in 

 cultures without potash. On the other hand, the results with potash mica and 

 nepheline stone were relatively good, though decidedly poorer than those 

 obtained with the normal culture containing potassium chlorid. 



These results were obtained in cultures in which the nitrogen was supplied 

 in the form of nitrate, but no better results were obtained when ammonium salts 

 were used, the observations differing in this respect from those in the case of 

 raw phospliates. 



Sand cultures with raw phosphates, I. S. Shulov (Izv. Moskov. Selsk. Khoz. 

 Inst. [Ann. Inst. Agron. Moscou], 15 (1909), No. 1, pp. 32-73, figs. 19). — 

 These experiments showed that while ammonium salts exerted a marked solvent 

 action on raw phosphates, potassium chlorid showed no such action, although 

 the conditions were apparently very favorable for the ])urpose. The substi- 

 tution of air nitrogen (calcium nitrate) for nitrate nitrogen increased the 

 assimilation of the phosphoric acid of raw phosphates by peas, although it 

 might have been assumed that the marked physiological alkalinity of the 

 calcium nitrate would depress assimilation. 



Raw phosphates of different origin showed decided variations in assimilability 

 by certain plants, particularly buckwheat, lupines, and peas, these crops show- 

 ing a higher degree of assimilation of the raw phosphate and responding more 

 readily to increasing applications. Experiments with tricalcium phosphate 

 showed an unfavorable effect upon assimilability as a result of heating. Ex- 

 traction of ashes in many cases increased the assimilability of the phosphoric 

 acid, this being especially true in the case of straw ash. 



In tests of culture solutions it was found that a normal culture containing 

 monocaleium phosphate and ammonium nitrate gave better results than the 

 ordinary combination of monopotassium phosphate and calcium nitrate, and the 

 latter gave better results than monopotassium phosphate and ammonium nitrate. 

 It appears that the f rst combination is more likely to give a neutral reaction 



