CEOP PRODUCTION IN THE C4REAT PLAINS AREA. O 
length of the period free from frost is more important in the produc- 
tion of corn than in the production of small grain. Young corn being 
easily injured by frost, planting must be delayed until there is little 
further danger from this source. Where the season is short, the crop 
may be caught by frost in the fall. This necessitates the use of short- 
season varieties hi a portion of the Great Plains area. 
SOILS OF THE GREAT PLAINS. 
As would naturally be expected in so extensive an area, the soils 
of the Great Plains present a great diversity; but as it is only that 
portion of the area which is adapted to dry farming with which these 
studies deal, all of the alluvial bottoms, the sand hills, the "bad lands," 
and the rough, broken, and mountainous portions are eliminated. 
This elimination greatly reduces the diversity of soil types to 
be considered. The 14 field stations already mentioned were 
located with a view to having each of them on soil representative 
of extensive areas. It is believed, therefore, that the soils of these 
stations represent nearly all of the important soil types to be found 
in the strictly dry-farming portions of the Great Plains. The con- 
clusions drawn from experiments conducted at these 14 stations, 
therefore, should apply to the Great Plains area as a whole, and those 
from individual stations, or from groups of stations, to extensive sub- 
divisions of the area. 
Space here will not permit of a detailed discussion of the soils at 
each station. Brief descriptions of the soils at these stations are 
given in a bulletin recently published. 1 
CROPS AND CULTURAL METHODS. 
The principal crops under investigation are spring wheat, winter 
wheat, oats, barley, corn, milo, and kafir. The methods of soil 
preparation include fall plowing, spring plowing, disking corn stub- 
ble, subsoiling, green manuring, and summer tillage, and listing for 
small grain, corn, milo 3 and kafir. Detailed descriptions of these 
various methods are given in the publications cited on page 1. 
RESULTS OF METHODS TESTED WITH VARIOUS CROPS. 
In this bulletin a table will be presented for each of the crops con- 
sidered, the results for milo and kafir being combined in one table. 
The first part of each table shows the average yields obtained at 
each station by each method under trial. It also shows the number 
of years and total number of plats used in obtaining the average. In 
the case of the small grains only, the method of seed-bed preparation 
1 Bulletin U. S. Dept. of Agriculture No. 214, entitled "Spring Wheat in the Great Plains area: 
Relation of cultural methods to production," 43 p., 1915. 
