6 BULLETIN 1172, U. S. DEPARTMENT OF AGRICULTURE. 
THE PLANT INTRODUCTION STATION. 
The Plant Introduction Station comprises approximately 210 acres 
of land located about 4 miles southeast of Chico at the edge of the 
valley floor and about 1 mile from the foothills of the Sierra Nevada 
Mountains. Its altitude is approximately 189 feet. It is traversed 
from east to west by a dry stream bed, which is bordered by a fringe 
of woods consisting principally of valley oak. This channel, which 
is used to conduct irrigation water from Butte Creek, a perpetual 
stream lying to the southeast of the station, is believed to have been 
at one time the old bed of that stream. With the exception of a 
small area extending into the foothill slopes, the topography of the 
station is quite level, with good drainage. 
son.. 
The soil is an alluvial silt loam. The type, which is known as Vina 
loam, comprises some of the most fertile lands of the valley. When 
farther removed from the foothills, this soil is usually 6 or more feet 
in depth and usually underlain by gravel. At the Plant Introduction 
Station the soil varies from the maximum depth to very shallow and 
is underlain by gravel or various undifferentiated soil materials. 
In general, it may be described as consisting of irregular bodies of 
deep soil interspersed with shallower areas and shallow spots, with 
an occasional gravel outcrop. The nonuniform condition has been 
a very disturbing factor in comparative experiments with cereals. 
The poorer spots manifest themselves principally in shorter, lighter 
straw and reduced yields. Many of the discrepancies in recorded 
data are due to this condition. 
CLIMATE. 
The climate at Chico is similar to that of other places in this 
portion of the valley. Its precipitation is somewhat greater than in 
places farther south or more nearly in the middle of the valley. 
Wind velocities also are lower than farther out in the valley or toward 
its southern end. The average temperatures usually are several 
degrees higher than at places in the southern extremity of the area. 
Precipitation. 
The average monthly, seasonal, and annual precipitation at Chico 
in the 51-year period 3 from 1871 to 1921, inclusive, is shown in 
Table 2. The average annual precipitation for the period was 23.69 
inches, and the average seasonal precipitation (September to May) 
was 23.24 inches, which is but 0.45 of an inch less than the annual. 
The season from September to May includes the time when the 
first fall rains come to the end of growth and maturity of cereal 
crops. When sufficient rain falls in September, plowing for grain is 
begun and the summer fallow prepared for seeding during that month. 
With no early rains, plowing is delayed until rain falls, although the 
preparation of a seed bed on summer fallow may proceed. 
3 United States Department of Agriculture. Weather Bureau. Summaries of Climatological Data. 
Section 15— Northeastern California [1871-1910]. U. S. Dept. Agr., Weather Bur., Bui. W, v. 1, sect. 15. 
1912. 
United States Department of Agriculture. Weather Bureau. Climatological Data, California Section, 
v. 1-25. 1897-1921. 
