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. 



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- 



