SOTT.S — FEETILTZERS. 727 



with ordinary snperpbospbatp. The action of phosphoric acid of metaphos- 

 phatc. however, is dwidedly inferior to tliat of the snperphosphates. On sandy 

 soil tlie etfei't (»f the dried and calcined sn|ierphosphates was less than that of 

 supcriihosphate dried at lt>(>^. It apjiears, theiefore, that the cliaracter of the 

 soil exerts an Inlluence upon the assimilation of these forms of phosphoric acid. 



The value of phosphoric acid in superphosphates and in Thomas slag', 

 r. DE Caluwe (Eiigrai.s, 23 (1908), No. J/o, p. 1075). — A review of the investi- 

 gations of de Molinari and Ligot referred to above. 



The factors which influence the fertilizing' effect of difficultly soluble 

 phosphates, H. G. Soderbaum (Landw. Vers. Stat., 68 {1908), No. 5-6, pp. 

 .',.li-',r,() : nh>i. in Jour. Clicin. Soc. [Loiulon], 9't (1908), No. 550, II, />. 728; Chem. 

 y.cuthl., 1908, II, No. 9, p. 819). — Tricalcinm pliosi)hate and bone meal combined 

 with nitrogen in different forms (sodinm and annnoninm nitrate, ammoninm 

 sulphate, and urea), and also with potassium chlorid and suli)hate and sodium 

 carbonate, were compared with superphosphate on oats and barley grown In 

 cylinders containing 25 kg. each of sandy soil. See also a previous note (E. S. R., 

 17, p. 1053.) 



On oats tricalcium phosphate gave slightly lower results with ammonium 

 nitrate and slightly higher results with ammonium suli>hate than with sodium 

 nitrate. On barley receiving bone meal, anunonium nitrate gave lower results 

 than sodium nitrate, annnoninm sulphate reduced the yield 4(i.(> iier cent, and a 

 mixture of sodium nitrate and annnoninm sulphate increased the yield (4.1 per 

 cent) as compared with sodium nitrate alone. The addition of potassium sul- 

 phate to the tricalcium phosphate and ammonium sulphate gave somewhat 

 higher results (with oats) than when potassium chlorid was used, but with 

 bone meal and ammonium sulphate, potassium chlorid gave distinctly better 

 results (with barlej-) than potassium sulphate. 



In another series of experiments, annnoninm salts (both nitrate and sulphate) 

 were more effective than sodinm nitrate in increasing the yield of oats when 

 us«'d with tricalcium phosphate and bone meal, respectively. Kone meal and 

 anunonium nitrate gave higher results with barley than sodium nitrate and 

 bone meal, while tricalcium jibosphate and ammoniiun nitrate gave lower re- 

 sults. Both phosphates, but especially the tricalcium phosphate, gave much 

 lower results with anunonium sulphate than with sodium nitrate. The addition 

 of soditnn carbonate ( furnishing sodium equivalent to that of the nitrate of 

 so<la ) to ammonium sulphate with bone meal gave a slightly (1.1 per cent) 

 higher yield (tf barley th.in sodinm nitrate and bone meal. With tricalcium 

 |iliosphate, the addition of sodium carbonate with ammonium suliihate nearly 

 donliU'd th(» yield obtained with annnoninm sulphate and tricalcium iihosphate, 

 although the yield was still more than ."><> per cent below that obtained with 

 sndinni nitrate and tricalcium ]ihosi)hate. 



With anunonium snlith.-ite and phosphates, sodium carbonate very slightly 

 rwlnced the yield of oats as compared with ammoniinn suljihate and phosphates 

 alone. 



While the author believes that the iihysiological reai'tion of the accompanying 

 nitrogenous fertilizer plays an inii'ortant part in determining the fertilizing 

 elTecl of fertilizers, as stated by rrianishnikov (K. S. li., IS, p. .">;{!») and others, 

 many other factors, such as kind of iilani, soil, an<l other fertilizing materials 

 use«l, may mask or even rever.se the inlluence of this factor. 



Increase or decrease of nitrogen in the soil by manuring. I>. .\. (Jii.chri.st 

 (Countii Northitiiih. Ed. Com.. Hill. II, pi>. 26-.29). — It is shown that in experi- 

 ments on grass land during 11 years the use of phosphatic fertilizers increased 

 the soil nitnigen about s."l lbs. per acre over that of soil ree«'lving no fertilizer. 

 The plats receiving sulphate of auunonia and nitrate of so»la in atldilion to the 



