WINTER WHEAT IN THE GREAT PLAINS AREA. 15 
early fall plowing into excellent condition for seeding. When this 
condition occurs, little difference is shown between early and late 
fall plowing. In years when the fall precipitation is limited, both 
the best stand and the best winter survival are found on late fall 
plowing. This condition is shown particularly in the results of 1915 
and 1916. The wide margin of difference in favor of early fall 
plowing in 1909 is due to the fact that at that time the grass still 
persisted on the late fall-plowed land. No winter wheat has been 
sown on disked corn ground at this station. 
Summer tillage shows the highest profit, $5.53 per acre. Listing 
is the most profitable of the continuous-cropping methods. Sub- 
soiling, on account of the expense involved, is the least profitable 
of the methods studied. Late fall plowing has given appreciably 
larger net returns than early fall plowing, as the extra labor involved 
in the latter method on the average does not increase the yield. 
ARDMORE FIELD STATION. 
Two types of soil are found on the Ardmore farm—Orman clay 
and Pierre clay. Both of these types hold a high percentage of 
available water and should show favorable results from the cultural 
methods that store moisture. In the Orman clay, on which type 
of soil most of the experiments have been conducted, gravel is found 
at depths of 2 to 4 feet. Crop yields have not been limited so much 
by the inability of the soil to hold all of the moisture taken in as by 
the texture of the soil, which makes penetration of rain on fallow 
land difficult. 
At Ardmore winter wheat failed in 1913 under all methods except 
summer tillage, which averaged in that year 8 bushels per acre. In 
1914 the crop was destroyed by hail. In the other two years under 
study the yields were good under all methods. Summer tillage has 
produced the highest average yield, but in 1916 three of the other 
methods gave higher yields. Early fall plowing, late fall plowing, 
and listing have averaged approximately the same. The difference 
in yield between subsoiling and disked corn ground is very small, 
both averaging considerably higher than early or late fall plowing 
or listing. (Table VIII.) 
The profits from summer tillage and green manuring are decidedly 
less than from the continuous cropping methods. The highest net 
return, $11.29 per acre, has been obtamed from disked corn ground. 
Late fall plowing, involving less expense, has been more profitable - 
than early fall plowing. While subsoiling has produced higher 
yields than listing, the profits from the two methods are approximately 
equal. On land continuously cropped to winter wheat, higher 
profits have been secured from subsoiling and listing than from early 
or late fall plowing. 
