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 subhumid 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 



1 The data and m;ip are from U. S. Department of Agriculture, Weather Bureau, 

 Climatological Service, South Dakota section, Annual Summary, 1011. 1912, 



