SOTLS FKRTILTZERS. 



V>19 



avor;iK<'. '"'t "i'''t "• li'.uMiiuiiious crops, masses, iiml liord ci-ojis in .^cnoral was 

 above the avera.ij:e. The total cost of tlie purification of the se\va;;e of F.runs- 

 wick by this nietliod was about 23 cents per year and per capita of population. 



Land treatment of sewage, II. T. Scoble (tSitrfcijur, 30 {UJ06), .Vo.s-. 770, 

 l>l>. .'/iS'-/,.T2 ; 777, pp. .',1C>-',S(i ; 11 >, pp. .IOO-.jOS ; 713, pp. r>28-r,Sl ; 11.',, pp. 556- 

 559; 115, pp. 580-58 Ji; lid. pp. 608-611; 111, pp. 632-635; 118, pp. 66',-66'J; 

 119, pp. 696-101 ; 180, pp. H 6-1 19). — A review of reports to the Itoyal Conuuis- 

 sion of England on this sul).ject (E. S. It., Hi, p. 10.">2). 



Phosphoric acid experiments on different kinds of soils, ^V. Sciineide- 

 wiNi), D. Meyer, and II. Frese (Landu-. Jahrh., 35 {1906). Ao. 6, pp. 921-936, 

 pi. 1). — The experiments liere rejiorted were made with 10' snils Ironi different 

 soiu'ces. The phosphoric acid content of llu>se soils and thcii' behavior in 

 pot experiments with oats wlicn fertilized witli piinspiiatic manures (super- 

 phosphate. Thomas slag, and hone meal) are shown in liie following table: 



Rchitioii (if phoKjilidric-itiiil cidiIciiI of snils In pliospliittc iiidiiiniin/. 



Kind of soil. 



Heavy loess loam soil 



Sandy soil 



Do 



Clay soil 



Sandy loam soil 



Sandy moor soil 



Loamy sandy soil 



Loess lonm soil 



Heavy louss loam soil 

 Do 



Total phos- 

 plioric acid 

 (diss(jlvt.'d 

 by 10 per 

 cent hy- 

 drochloric 

 acid). 



Per cent. 

 0.81 

 .16 

 .05 

 .16 

 .09 

 .07 

 A)r> 

 .08 

 .15 



Phosphoric 

 acid solu- 

 ble in 2 per 

 cent citric 

 acid. 



Per cent. 

 0.45 

 .05 

 .02 

 .01 

 .01 

 .01 

 .01 

 .02 

 .02 

 .02 



Phosphoric-acid 

 content of the crop. 



Per cent. 

 0.86 

 .92 

 .57 

 .57 

 .49 

 .63 

 .63 

 .45 

 .47 

 .63 



Per cent. 

 0.16 

 .•36 

 .06 

 .07 

 .06 

 .06 

 .09 

 .05 

 .06 

 .11 



Response to phospliatic fer- 

 tilizing. 



No increase of yield. 



Do. 



Do. 

 Small increase of yield. 



Do. 

 Decided increase of yield. 



1)0. 



Do. 

 Do. 

 Do. 



The results obtained indicate a certain relation in some cases ]>etween the 

 phosphoric-acid content of llie soil and the need of phosi)hatic fertilizers. 

 In general, sandy soils jiooi- in lime, magnesia, iron, alununa. and total phos- 

 phoric acid, but containing aiii)reciable amounts of citric-acid-soluide jihos- 

 phoric acid, <lid not respond to api)lications of phosphates. On the otJier hand, 

 beav.y soils rich in lime, magnesia, iron, and alniuina were bcnetited b,y 

 applieations of phosphat(>s even w lien containing much larger amounts of 

 eitric-aeid-soluble i»h()si)horic acid than the sand.v soils. In other words, 

 heav.v soils rich in the const it ueuls named must contain nnich more citric- 

 acid-soluble phosphoric ;icid t'.ian sandy soils <if the kind described before 

 I>hosi)hatic fertilizers cease to be etfe<-live in increasing the yield. 



Thomas slag gave as good i-esnlts as snp:'rpliosphate on light sandy soils, 

 and bone meal was also V(>ry effective on such soils. In the hea\y soils the 

 Thomas slag was only 47 per cent as effective as superphosphate and l)one 

 meal was practicall,v witbotu effect. The efticieiicy of the latter ai>|)arentl,v 

 depends upon the reaction of the soil. 



A rather definite relation between (be ])hosplioric-a<-id content of the crop 

 and the soil re(piirements was shown in these exiu'riments. the soils producing 

 plants low in ]»hosiihoric acid, as a I'lile. responding to applications of i)lios- 

 phatic fertiliz(>rs and vice versa. 



Fertilizer experiments with different sources of phosphoric acid, M. J. 

 Pattekso.n {.]1 (Ill/Id ikI Stn. liiil. U'l. pp. Il3-1'i'i). — The experiments here 

 recorded are a continuation of those rei)orted in Bulletin U8 of the station 



