GROWING FIELD CROPS IN SUGAR-BEET DISTRICTS. 5 
Some of the crops studied can be grown without the practice of 
irrigation in the semiarid climate of Colorado. However, to reach 
the maximum yield it is necessary to irrigate. There are other crops 
which can not be grown at a profit except by irrigation. Sugar beets 
are never grown in this region without irrigation, and cantaloupes and 
cucumbers are not commercially profitable without it. Beans, po- 
tatoes, and small grains are grown on both irrigated and nonirrigated 
lands at a profit, with the average production per acre much greater 
on the irrigated areas. 
Precipitation and the seasonal distribution of rainfall are much the 
same for the two valleys. Fortunately, the major portion of the an- 
nual rainfall occurs during the growing season. There is a some- 
what heavier rainfall in the months of March, April, and May in the 
South Platte Valley than at Rocky Ford. (See Table II.) This 
with the slightly increased temperature of the Rocky Ford district 
accounts partially for the fact that it is customary there to irrigate 
immediately after or previous to planting some crops. (Fig. 2.) 
Fig. 2.— Watering sugar-beet seed for germination, showing an example of row irrigation. The furrows 
must be well made, and careful attention should be given to the running of the water. The furrows 
are made as the seed is planted. 
The Greeley and Fort Morgan growers do not practice spring irriga- 
tion, as there is, as a rule, sufficient precipitation or stored moisture 
in the soil to germinate the seed and start the crops. 
Some rains which fall during July, August, and September do not 
benefit the crops greatly; in fact, they may do serious damage by 
forming a heavy crust or by causing the crop to lodge. Many of these 
rains come in heavy showers, when the run-off is great, and others in 
light showers which do not penetrate the soil. The average being 
very low, the evaporation is rapid and excessive. In some years 
because the winter rains are light, the fields remain dry and hard and 
are in such poor condition in the spring that unless irrigation is prac- 
ticed the seed germinates slowly and unevenly. 
