ABSORPTION OF ASH-CONSTITUENTS 



89 



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 Ught 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. 



NaH2P04 Phosphorite NaHaPO/ Phosphorite 



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

 in sand cultures. {After Prianishnikov.) 



