4 BULLETIN 1421, U. S. DEPARTMENT OF AGRICULTURE 
SCOPE OF THE INVESTIGATION 
The investigation covered a four-year period, 1919 to 1922 in- 
clusive. It included (1) a study of the agricultural development and 
readjustments of the Twin Falls south side project, (2) a business 
analysis of the farms studied during each of the years 1919-1922, 
(3) the cost of producing each of the seven primary crops grown in 
1919, 1920, and 1921, and (4) the average cost of keeping work horses 
and the cost of horse labor per hour in 1921. 
The information was obtained by the survey method. In 1919, 
230 farm-survey records were obtained, 216 in 1920, 215 in 1921, 
and 87 in 1922. Because of their incompleteness, inaccuracy, or 
because of certain unusual features of farm practices or type of farm- 
ing, several of the records obtained have not been used. During 
the three years that cost of crop production studies were conducted 
a total of 233 usable records were obtained for wheat, 184 for alfalfa, 
122 for sugar beets, 120 for potatoes, 120 for beans, 97 for red clover 
seed, and 30 for alsike cloverseed. In 1921, 151 records were obtained 
showing the yearly cost of keeping work horses on these farms. 
An attempt was made to obtain records from the same farms each 
year so that a continuous study might be made of individual farms, 
but this was made impracticable because of the frequent changing 
of farm operators and changes in the size of the farms, owing to 
sales of farms, leasing of additional land by some operators and the 
changing of tenants. 
THE DISTRICT STUDIED 
The district studied is located in Twin Falls County near the 
center of the Twin Falls south side irrigation project (fig. 2). The 
farms visited are all within 10 miles of the city of Twin Falls and all 
of them are below the high line irrigation canal. The average 
elevation of the area is approximately 3,800 feet. 
The Twin Falls south side irrigation project as a whole is a very 
uniform body of land.t’ In round numbers about 203,000 acres are 
under irrigation. The topography varies from nearly level to un- 
dulating and gently rolling. In places there are some steep slopes. 
Practically the entire project is well drained and but few localities 
have become seeped. Probably because of the undulating and slop- 
ing nature of the land the furrow system of irrigating has come into 
almost universal use. 
The soil of the project is also remarkably uniform.? There are 
but few types of soil, most of which are silt loams. One of these, 
the Portneuf silt loam, occupies from 90 to 95 per cent of the area 
of the project. There are two phases of this type—the shallow and 
the deep. The deep strongly predominates. The shallow phase 
occurs where the solid rock or hardpan is found 8 feet or less below 
the surface, and the other where the surface soil is deeper than 3 feet. 
This soil is well supplied with lime, potash, and phosphorus. Like 
most arid soils, however, it is rather low in organic matter and 
vey: Geology and Water Resources of the Snake River Plains of Idaho. ‘ : 
? For a discussion of the soils of the district studied see Advance Sheets-Field Operations, Bureau of 
Soils, 1921: Soil Survey of the Twin Falls Area, Idaho. 
