Manuring and Rotations 89 
the farm, (6) the presence of pests and diseases, (7) the 
amount of labor that is available, and (8) many other 
conditions. tt 
In several of the beet-producing areas where beets have 
been raised almost continuously for many years, the 
nematode has made it impossible to continue the crop 
unless a rotation is introduced. In planning a rotation 
for these conditions, it is necessary to eliminate plants 
that will foster this pest. Crops available for this pur- 
pose are listed in Chapter XIII. 
In several districts land has become so high-priced that 
it is impossible to raise at a profit many of the crops that 
would ordinarily be included in rotations with sugar- 
beets. Where a condition of this kind is found, the plan- 
ning of a good rotation becomes a real problem. The 
plant-foods removed by the beet crop may be added in 
commercial fertilizers, but this does not keep out injurious 
diseases and pests, neither does it provide the proper 
balance in the farm business. A short rotation used in 
some of the areas of California having high-priced land 
consists of beans and sugar-beets. 
In the Arkansas Valley of Colorado and western Kan- 
sas, the cucurbit group of crops forms an important part 
of the rotation with sugar-beets. Cantaloupes are the 
principal of these; cucumbers are also important. These 
crops, with alfalfa and in some cases potatoes, make the 
principal crops to alternate with beets. 
In northern Colorado and in parts of Utah, several 
canning crops, such as peas, beans, and tomatoes, enter 
into the rotation. These crops, taken with alfalfa, pota- 
toes, sugar-beets, and grain, enter into most of the ro- 
