466 NATUEE AND PROPERTIES OP SOILS 



STJLFUB AND SULFATES AS FERTILIZERS ^ 



The use of these substances as a means of increasing plant 

 growth when applied to soils has recently received much at- 

 tention. While sulfates have been used for centuries as a 

 soil amendment, it is only within the last few years that sulfur 

 itself has been applied to soil. The question of the effect of 

 the latter has received considerable study, not only in France 

 and Germany but in this country as well. The influence of 

 both sulfur and sulfates may be a direct nutrient relationship 

 or the action may be that of a soil amendment. Only in case 

 the former influence occurs could these materials be rated as 

 fertilizers. 



262. The use of free sulfur. — Boullanger ^ in 1912 added 



^ Another group of fertilizers may be mentioned — the so-called catalytic 

 fertilisers. Such materials are supposed to aid plant growth by accelerat- 

 ing natural soil processes. The catalytic action of any material is very 

 difficult to establish when it is added to the soil, since the soil itself 

 carries many substances of a catalytic nature. Manganese has been most 

 seriously considered as a catalytic fertilizer. 



Konig, J., Hasenbaumer, J., and Coppenrath^ E., Einige Neue Mgen- 

 schaften des Aclcerhodens; Landw. Vers. Stat., Band 63, Seite 471-478, 

 1905-1906. 



May, D. W., and Gile, P. L., The Catalase of Soils; Porto Rico Agr. 

 Exp. Sta., Circ. 9, 1909. 



Sullivan, M. X., and Reid, F. R., Studies in Soil Catalysis; XJ. S. 

 Dept. Agr., Bur. Soils, Bui. 86, 1912. 



Konig, J., Hasenbaumer, J., and Coppenrath, E., Besiehungen zwischen 

 den MgenscJiaften des Bodens und der Nahrstoffaufnahme durch die 

 pflauBen; Landw. Vers. Stat., Band 66, Seite 401-461, 1907. 



Kelly, M. P., The Influence of Manganese on the Growth of Bine- 

 apples; Jour, Ind. and Eng. Chem., Vol. I, p. 533, 1909. 



Sullivan, M. X., and Robinson, W. 0., Manganese as a Fertilizer; 

 U. S. Dept. Agr., Bur. Soils, Circ. 75, 1912. 



Skinner, J. J., and Sullivan, M. X., The Action of Manganese in Soils; 

 U. S. Dept. Agr., Bui. 42, 1914. 



Skinner, J. J., and Reid, P. R., The Action of Manganese Under Acid 

 and Neutral Soil Conditions; XJ. S. Dept. Agr., Bui. 441, 1916. 



Bertrand, G-., The Action of Chemical Infinitesimals in Agriculture; 

 Address before 8th Inter. Cong. App. Chem., New York, 1912. 



Ross, W. H., The Use of Badioactive Substances as Fertilizers; U. S. 

 Dept. Agr., Bui. 149, 1914. 



Hopkins, C. G., and Sachs, W. H., Badiwm as a Fertiliser; 111. Agr. 

 Exp. Sta., Bui. 177, 1915. 



* Boullanger, E,, Action du soufre en fleur sur la ^vegetation; Oompt. 

 Rend. Acad, Sci. Paris, T. 154, pp. 369-370, 1912. 



