THE BEET SUGAR INDUSTRY. 79 
portions and kinds of food which this plan involves, must soon impair results, Three 
crops in succession in Nebraska’s rich soil showed marked deterioration in quality. 
Constant cropping with beets also tends to perpetuate or multiply any pests (insect 
or fungus) of this plant. It is true that beets have been grown continuously on the 
same land in Califurnia for a dozen years, without apparent injury to yield or qual- 
—s : : | 
TYPES OF SUBSOIL PLOWS 
To follow in the furrow after the first plowing by ordinary plows. 
GANG PLOW WITH SUBSOILING ATTACHMENT. 
ity, but this does not gainsay the axiom above laid down. Thus far, best tonnage 
and quality have been secured in California from beets grown on the land every third 
year, and in Nebraska every fourth year. 
New land should be subdued, as stated on Page 78, before being grown to beets. 
This crop should always follow corn or small grain, because these being harvested 
early, the land is free for the fall plowing that is absolutely essential to best results 
with the beet. In Nebraska corn does not seem to do well after beets, neither 
