ABSORPTION OF ASH-CONSTITUENTS 



95 



of the plant but also upon that of the soil. That the small grains fail to assimi- 

 late phosphorite in sand cultures does not necessarily mean that they behave 

 in the same way in cultures with other kinds of soil. In Prianishnikov's experi- 

 ments summer-rye was grown in black soil from the Government of Voronezh, 

 in light sandy loam from the Government of Minsk, and in two light-colored, 

 uncultivated sands ("Podsol") from the vicinity of Moscow, all four soils being 

 fertilized with phosphate rock. His results are presented in the following table. 



NaH 2 P04 Phosphorite NaH 2 PO* Phosphorite 



Fig. 59. — Comparative effects of sodium phosphate and of phosphorite upon millet and pea 



in sand cultures. (After Prianishnikov.) 



Soil 



Yield of Grain 



Unferti- 

 lized 



Fertilized 



with 



Phosphorite 



Total Weight of Grain 

 and Straw 



Unferti- 

 lized 



Fertilized 



with 



Phosphorite 



Increase 



in Yield 



Due to 



Fertilizer 



per cent. 

 3 



24 

 226 



372 





