Manuring and Rotations 77 
is brought together and carefully studied, a fairly ac- 
curate judgment of the soil requirements may be made. 
The practice of applying any kind of fertilizer the dealer 
may have for sale, without making a thorough investi- 
gation, cannot be too strongly condemned. 
COMMERCIAL FERTILIZERS FOR BEETS 
In some regions where an abundance of farm manure is 
available, little or no commercial fertilizer may be needed 
for beets. There are many sections, however, where the 
supply of manure is insufficient. In these places com- 
mercial fertilizers will find increased use. The kind of 
fertilizer will of course depend largely on soil conditions. 
From Table IV it is evident that the sugar-beet plant 
uses relatively large quantities of potassium, which means 
that sugar-beet fertilizers should be well supplied with 
this element. After this requirement is satisfied, an 
effort should be made to supply a well-balanced fer- 
tilizer for the average soil. Voorhees! shows that sugar- 
beets grown on light soils often require potash, while on 
heavier loamy soils this element is not needed. He brings 
out the fact that fertilizers that produce too rapid or too 
prolonged growth tend to reduce the percentage of sugar. 
Phosphoric acid is one of the most necessary constituents 
to produce a large and rapid leaf growth in the early part 
of the season when the plant is preparing itself for the 
storage of sugar. This fertilizer should, therefore, be 
present in comparatively large quantities in the soluble 
form during the early period of growth. 
1 Voorhees, E. B., ‘“‘Fertilizers,” pp. 235-240. 
