2 BULLETIX 1293, IT. S. DEPARTMENT OF AGRICULTURE 
liston. The results of closely coordinated work conducted by the 
office mentioned at 21 other stations on the Great Plains have been 
of great assistance in interpreting the data. 
The experiments at Dickinson were started in 1907 and have not 
been interrupted. They were extended in 1923 to obtain information 
on problems that have assumed importance and were not covered in 
the original plans. The experiments at Hettinger were started in 
1911 and continued through 1922. Those at Williston were begun 
in 1909 and continued through the crop year of 1920. A part of the 
Williston substation was irrigated, but ,these experiments were on 
dry land located above the ditch. 
At all three stations the first crop grown in these experiments was 
on virgin soil. Preparations for the work were begun by breaking 
the native sod during the summer of the year preceding the one cited 
as the time when the experiments started. The first year's crop was 
on breaking, and all plats were uniform in preparation and treat- 
ment. The results of the first year, when all plats received uniform 
treatment, are included in the tables and discussions of average 
yields, but are not included in the tables of yields from which com- 
parisons of different methods and treatments are made. 
CLIMATIC CONDITIONS OF THE REGION 
PRECIPITATION 
The quantity and the distribution of the precipitation are similar 
at the three stations and are characteristic of the region in which 
they are located. The average precipitation for the year, the four 
months from April to July, the five months from April to August. 
the six months from April to September, and the proportions of the 
seasonal quantities to the whole are given in Table 1 for each of 
these stations and for Bismarck, N. Dak., and Moorhead, Minn. 
Bismarck is near the center of the State and Moorhead is just across 
the eastern State line from Fargo. The data are from published 
reports of the United States Weather Bureau and in each case bring 
the record from its beginning down to and including 1920. 
The annual precipitation Avas 15.41 inches at Dickinson, 14.52 
inches at Hettinger, 14.42 inches at Williston. 17.10 inches at Bis- 
marck, and 23.62 inches at Moorhead. A relatively high proportion 
of the precipitation falls Avhile crops are growing, a fact of great 
importance to the agriculture of the region. The average precipita- 
tion for the four months from April to July was 9.02 inches at Dick- 
inson, 9.31 inches at Hettinger, and 8.11 inches at Williston. These 
quantities are 58.5, 64.1, and 56.2 per cent, respectively, of the annual 
precipitation at the three places. 
In both the five-month period from April to August and the six- 
month period from April to September the precipitation was greatest 
at Dickinson, least at Williston, and intermediate at Hettinger. 
Dickinson is favored the most and Williston the least in both the 
quantity and the distribution of the rainfall. The differences may. 
however, be due, in part at least, to differences in the lengths of the 
records. 
