14 BULLETIN 1139, U. S. DEPARTMENT OE AGRICULTURE. 
CONDITIONS AT INDIVIDUAL STATIONS. 
The soil at Assinniboine is glacial till and offers no serious phys- 
ical difficulty to the penetration of moisture or plant roots. All the 
years for which moisture determinations are given were years of low 
precipitation, and in these years even in the fallow plats available 
moisture has never been present in the sixth foot. Neither plat A 
nor B has had the third foot filled with moisture. It will be noted 
that in two years out of three plat A has been moist to a greater 
depth than plat B. All of the available moisture has been removed 
from the soil on all plats all years except from plat C or D in 1917. 
In that year the crop, in spite of its need for water, was not able 
to use all the water from the fourth foot and was unable to remove 
any moisture from the fifth foot. This year represents a case where 
the demands of the crop for water were so heavy that the crop roots 
were unable to extend themselves and take up moisture rapidly 
enough to maintain life in the crop. The wheat suffered a forced 
ripening even while available water was present at a depth that could 
have been reached by the wheat roots under conditions less adverse. 
At Huntley the full storage capacity of the soil has never been 
utilized. This has been due in a large measure to the high water- 
holding capacity of the soil, which has prevented the limited raim 
fall at this station from penetrating to any great depth. In addition, 
there seems to be an increased difficulty of water penetration in the 
lower depths. That there is no impervious layer of soil that pro- 
hibits moisture movement has been shown on other plats which have 
become wet to a depth of at least 6 feet. All of the available mois- 
ture has been removed each year from all plats. Plats A and B have 
shown very little difference in water storage. Plat C or D has stored 
the most moisture, but has never stored moisture to a depth where it 
could not be utilized. 
The soil at Sheridan has been easily penetrated by moisture and 
by roots. Little difference is shown between plats A and B in water 
storage, and neither of these plats has been wet deep enough to 
utilize fully the moisture-storage capacity of the soil. Plat C or D 
has carried available moisture in all 6 feet in two of three years. 
In 1919 the wheat crop removed all available water from all foot 
sections of this plat, but the yield was seriously reduced by drought 
injur} 7 . In 1920, when the crop was not seriously injured by drought, 
it used but did not exhaust the water content of the fifth and sixth 
foot sections. 
At Williston the A and B plats have never had available moisture 
present below the fourth foot. That this has been due to lack of 
precipitation rather than to difficulty of soil penetration is indi- 
cated by the fact that plat C or D has each year had available water 
present in all 6 feet of soil. The moisture in plats A and B has 
always been exhausted by harvest in all depths below the first foot. 
In a few cases there has been enough rain before harvest to raise 
the content above the minimum point at that time, though all avail- 
able moisture had been exhausted earlier in the season. There is 
little difference between plats A and B in the quantity of water 
stored, but the difference seems to favor plat A. Plat C or D has 
each year had available moisture in all foot sections. The extent to 
