GROWING SUGAR BEETS IN COLORADO. 7 



CLIMATIC CONDITIONS. 



The climate of Colorado is semiarid. To obtain maximum yields 

 under semiarid conditions irrigation must be practiced. While it is 

 possible to grow certain crops under dry-farming methods, some im- 

 portant staples, such as the sugar beet, are confined entirely to the 

 irrigated valleys (fig. 3). 



The three distinct areas in Colorado where farmers give consider- 

 able attention to beet culture are in three more or less extensive 

 drainage basins, namely, the South Platte River and its tributaries, 

 the Arkansas Valley, and the western slope. This bulletin is con- 

 cerned with the first two areas. Rocky Ford was selected as a typical 

 area in the Arkansas Valley. Fort Collins, Greeley, and Fort Morgan 

 are important beet-growing centers adjacent to and in the valley of 

 the South Platte. 



Table II. — Average annual rainfall for three districts in northeastern Colorado and one 

 district in the Arkansas ( Valley in inches) . 



January 



February 



March. .1 



April 



May • 



June 



July 



August 



September 



October 



November 



December 



Total annual precipitation 



Elevation . feet 



Rocky Ford, 

 1889-1908. 



Mean. 



0.32 



.34 



.68 



1.66 



1.92 



1.35 



2.76 



1.37 



.78 



.90 



.46 



.44 



12.98 

 4,177 



Fort Collins, 

 1873-1908. 



Mean. 



0.49 



.52 



.98 



2.23 



3.06 



1.59 



1.90 



1.21 



1 16 



1.02 



.33 



.32 



14.81 

 4,985 



Greeley, 

 1S88-1908. 



Mean. 



0.34 



.37 



.81 



1.82 



2.61 



1.33. 



1.80 



.97 



.82 



.82 



.33 



.25 



12.27 

 4,639 



Fort Morgan, 

 1889-1908. 



Mean. 



0.26 



.31 



.69 



1.77 



2.42 



1.75 



2.41 



1.56 



.70 



.80 



.30 



.29 



13.26 

 4,338 



Precipitation and seasonal distribution of rainfall are much the 

 same for the four counties. The major portion of the annual rainfall 

 occurs during the growing season. Generally speaking, the rainfall 

 for April, May, and June is somewhat lower at Rocky Ford than at 

 the other points, which accounts partially for the fact that it is cus- 

 tomary there to irrigate immediately after planting, whereas in 

 northern Colorado the grower invariably counts upon starting the 

 crop with the spring precipitation. 



The light rains which fall during July, August, and September do 

 not benefit the crops greatly. In fact, they may do serious damage 

 either by crust formation or by simply sprouting the seed without 

 furnishing moisture enough for a satisfactory subsequent growth. 

 The late fall and winter months are marked by few light rain or snow 

 storms. The water which falls from November to March is probably 

 sufficient one season in four to provide some moisture for crop 

 production. When the winter rains are light, the fields remain hard 



