.July a8,1923 
Efficiency of Phosphatic Fertilizer 
193 
in the cases of acid phosphate, basic slag, and double superphosphate 
than in the case of bone meal or rock phosphate. 
(9) Acid phosphate continued to lose in efficiency the longer it re¬ 
mained in the soil, although after the first 20 to 30 days the loss was 
exceedingly small. That such losses in efficiency are of general occur¬ 
rence and that they are due to the action of soil constituents rendering 
the phosphoric acid unavailable to the plant is indicated by the fact 
that, as a rule, only 10 to 20 per cent of the phosphoric acid applied is 
recovered in the crop, whereas 60 to 90 per cent of the nitrogen or potash 
applied is commonly recovered. 
literature CITED 
<i) Bauer, F. C. 
1921. THE RELATION OF ORGANIC MATTER AND THE FEEDING POWER OF PLANTS 
TO THE UTILIZATION OF ROCK PHOSPHATE. In Soil Sci., V. 12, p. 21-41. 
References, p. 40-41. 
(2) Chirikov, Th. V. 
1914. zur frage Ober die lOsende wirkung der wurzeln. In Zhur. 
Opuitn. Agron. (Russ. Jour. Exp. Landw.), v. 15, p. 54-65. In Russian. 
German r6sum6, p. 64-65. 
{3) 
1917. QUELQUES DONNIES CONCERNANT LE POUVOIR DISSOLVANT DBS EXCRE¬ 
TIONS RADICULAIRES CHEZ LES PLANTES SUPERIEURES. In Zhur. 
Opuitn. Agron. (Jour. Agr. Exp.), v. 17, p. 289-338. In Russian. 
French r£sum6, p. 338. 
<4) Gedroiz, K. 
1911. AUF WELCHEN BOdEN WIRKT DER PHOSPHORIT. DIE MIT BASEN GESAT- 
tigten und ungESattigten bOden. In Zhur. Opuitn. Agron. (Russ. 
Jour. Expt. Landw.), v. 12, p. 529-546. In Russian. German sum¬ 
mary, p. 539-546. 
(5) Gile, P. L., and Ageton, C. N. 
1914. the red clay soil of porto Rico. Porto Rico Agr. Exp. Sta. Bui. 14, 
( 6 ) 
( 7 ) 
24 p. 
and Carrero, J. O. 
1916. a plan for testing efficiencies of fertilizers. In Jour. Amer. Soc. 
Agron., v. 8, p. 247-255, fig. 8. 
1918. THE BAT GUANOS OF PORTO RICO AND THEIR FERTILIZING VALUE. Porto 
Rico Agr. Exp. Sta. Bui. 25, 66 p, 
(8) Hartwell, Burt L. 
1921. efficiency of fertilizers and other manures. In R. I. Agr. Exp. 
Sta. 33d Ann. Rpt. [1920], p. 7-9. 
(9) Jordan, W. H. 
1913. studies in plant nutrition: i. N. Y. State Agr. Exp. Sta. Bui. 358, 
p. 11-30. 
(10) Kellner, O., and BOttcher, O. 
1900. untersuchungen Ober die dOngerwirkung der knochenmehl- 
phosphorsaure. In Deut. Landw. Presse, Jahrg. 27, p. 665-666. 
■(h)- 
1910. UNTERSUCHUNGEN OBER DIE DANGER WIRKUNG DER KNOCHENMEHL- 
phosphorsaure. In Deut. Landw. Presse, Jahrg. 28, p. 194-195, 204. 
(12) Kossowitsch, P. 
1904. tiBER DIE GEGENSEITIGE EINWIRKUNG (WECHSELWIRKUNG) DER NAHR- 
SALZE BEI DER AUFNAHME MINERALISCHER NAHRUNG DURCH DIE 
pflanzen. In Zhur. Opuitn. Agron. (Russ. Jour. Exp. Landw.), v. 5, 
p, 581-612. In Russian. German rs£um6, p. 598-612. 
<13) — 
1909. PFLANZE, PHOSPHORIT UND BODEN NACH VERSUCHEN DES LANDWIRT- 
SCHAFTLICHEN CHEMISCHEN LABORATORIUMS ZU ST. PETERSBURG. 
In Zhur. Opuitn. Agron. (Russ. Jour. Exp. Land.), v. 10, p. 782-842, 
illus. In Russian. German r£sum6, p. 839-842. 
(14) Libchti, P. 
1915. OBER DEN EINFLUSS EINER KALKDONGUNG AUF DIE WIRKUNG VERSCHIE- 
DENER PHOSPHORSAUREDONGEMITTEL WURDEN VERSUCHE MIT HAFER 
und karotten durchgefOhrt. In Jahresber. Agr. Chem., Jahrg. 58, 
p. 119-120. 
