2 BULLETIN 39, U. S. DEPARTMENT OF AGRICULTURE. 
NEED FOR IMPROVEMENT. 
While the showing made by the above totals is impressive, it does 
not imply that there is no further opportunity for improvement. The 
acre yields have not increased during the period, but have remained 
about the same, fluctuating according to the quantity and distribution 
of the rainfall. As there is relatively little new land available that 
is adapted to the profitable production of these crops, future increase 
in production must come largely through increased yields per acre. 
The present average yields, 12 bushels for wheat, 26.3 bushels for 
oats, and 23.8 bushels for barley, are not enough. Production must 
be increased to keep pace with the constant increase of population. 
Whether or not production is increased will depend partly upon the 
improvement of economic conditions. There is now far too much 
land farmed by short-term renters who care little about crop or soil 
improvement. It rests largely with the landowners whether or not 
the yields per acre are to be increased. 
The requirements for crop improvement are essentially the fol- 
lowing : 
(1) Better varieties. (4) Better soil treatment. 
(2) Better seed. (5) Better tillage and cultivation. 
(3) Better rotations. (6) Better economic conditions. 
It is the purpose of this paper to discuss the first two essentials, 
better varieties and better seed, and to present the results of investi- 
gations pertaining thereto. 
CLIMATIC CONDITIONS. 
The data which follow and the rainfall map x (fig. 1) will aid in the 
proper interpretation of the results here reported. It will be noted 
that one of the stations, Brookings, is located in the subhumicl belt 
where the rainfall averages from 20 to 25 inches, while Eureka, 
Highmore, and Cottonwood, the other three stations from which re- 
sults are reported, are all located in the semiarid belt where the aver- 
age rainfall is from 15 to 20 inches. This quantity of rainfall would 
be sufficient to produce a cereal crop every year with good farming 
methods if it was not for the frequently recurring hot winds which 
blow from the south and southwest during the summer months. At 
such times evaporation and transpiration are excessive, so that the 
common cereals are severely damaged and sometimes destroyed. 
Under these conditions marked differences appear in the ability of 
varieties to utilize what little moisture there may be in the soil. A 
great deal also depends upon the stage of growth of the crop at the 
time these severe conditions occur, the flowering period being the 
time when it is most subject to injury. It is for this reason that so 
much confusion exists regarding the desirability of early or late 
ir rhe data and map are from IT. S. Department of Agriculture, Weather Bureau, 
Climatological Service, South Dakota section, Annual Summary, 1911. 1912. 
