Soils 71 
crease very rapidly when conditions are favorable. Many 
of the diseases of plants and animals are caused by bac- 
teria. This does not mean that all are harmful; many 
are decidedly beneficial. 
These germs cause the decay of the coarse organic 
matter of the soil and assist in the formation of the more 
useful humus. They are exceedingly important in con- 
nection with the nitrification, that is, with the transfor- 
mation of nitrogen from the unavailable form to the 
nitrates, which are taken up by crops. Certain forms of 
bacteria also assist in fixing the nitrogen of the air and 
in making it into a food for plants. This is done mainly 
in connection with the legume crops, although some forms 
fix nitrogen without the aid of legumes. 
SELECTING A SUGAR-BEET SOIL 
As previously stated, sugar-beets do not absolutely re- 
quire any given kind of soil; they are successfully raised 
on almost every type of soil when other conditions are 
favorable. This does not mean that all soils are equally 
well suited to raising the crop. Usually it does not pay 
to raise beets on any but well-adapted soils. 
A number of conditions must be strictly avoided. One 
of these is a hardpan near the surface that would inter- 
fere with the deep rooting of the beets. Another condi- 
tion to be avoided is a water-logged soil. Of course 
this can usually be overcome by drainage, but as a rule 
beets should not be planted until after the drain is in 
operation. 
So far as texture is concerned, a loam is best adapted 
