to agricultural research stations. Personnel from the USDA/Agriculture 
Stabilization and Conservation Service were available in each county 
to collect the required intensive test site ground truth data. 
Intensive Test Sites 
The intensive test sites are 5 x 6 miles in size. Three flight- 
lines, six-miles long are located across each site. The number of 
fields of major cover types for each site for 1975-76 are summarized 
in Table 1. 
Finney County, Kansas 
  
The test site is located in the High Plains Tableland physiographic 
area; 38? 10' N latitude and 100? 41' W longitude. The elevation of the 
site is 900 meters. It is overlaid by 3 to 10 meters of loess from the 
early Wisconsin age. The area has a distinct continental type of climate 
characterized by abundant sunshine and constant wind. Most of the pre- 
cipitation falls during the early part of the year with a rapid decline 
in the probability of receiving adequate rainfall during July and August. 
Thus, the growth cycle of winter wheat is well-matched to the available 
moisture supply. Average annual precipitation for Finney County is 
48.5 cm with 14.3 cm from March to May, 20.1 cm during June to August, 
9.7 cm between September and November, and 4.4 cm from December to 
February. 
The soils of the test site are in the Mollisol order, Ustoll sub- 
order, and Argiustolls great group. Mollisols are soils that have 
nearly black, friable, organic-rich surface horizons high in bases. 
Ustolls are formed in semi-arid regions and are dry for long periods, 
or have subsurface accumulations of carbonates. The major soil series 
in the area are Richfield and Ulysses which are deep, fertile, well- 
drained, nearly level to gently sloping, loamy soils of the upland 
that are well-suited to cultivation. 
The major crops in Finney County are wheat and grain sorghum 
which account for about 60 and 20 percent, respectively, of the total 
cropland. The majority of wheat is produced following summer fallow 
practices, although an increasing amount is being irrigated. Winter 
wheat is seeded in September or early October, then is dormant from 
December to February.  Green-up occurs in March, by mid-May the crop 
is fully headed, and harvest is typically completed during the first 
week of July. 
Williams County, North Dakota 
  
This test site is located at 48? 9' N latitude and 103? 25' W 
longitude. It is representative of the cool temperature semi-arid 
areas of the northern Great Plains where annual precipitation averages 
33 to 38 cm. The site is located at an elevation of 650 meters and