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4956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 
YEAR 
Fig. 3. Precipitation trends at Minnedosa. Manitoba. 1956-72, 
ground moraine with level to undulating topography. Soils 
on the study area are black loam to clay loam, developed 
on medium-textured, moderately calcareous boulder till of 
mixed limestone, shale, and granitic rock origin (Ehrlich 
et al. 1957; Ehrlich and LeClaire 1958). This composition 
is classified as the Newdale association. Surface stones occur 
in soils throughout the area. Some terminal moraine 
deposits with slightly more abrupt topographic features and 
containing coarser-textured materials occur in the south- 
eastern portion of the area. 
The intensive study area south of Minnedosa lies within 
the Newdale smooth phase. Although the topography 
appears relatively flat, notable relief occurs in the form of 
low knolls and slight depressions. Small areas of degrading 
black and degrading black-meadow soils have developed 
under woodland invasion on northern and eastern slopes. 
Surface runoff and internal drainage are slow and a large 
percentage of the soils are imperfectly to poorly drained. 
The better drained Newdale soils are naturally fertile and 
well suited to production of grain and forage crops. These 
soils have good water retention capacity, are neutral to 
slightly alkaline in pH, and have high organic matter con- 
tent. 
The extensive area northwest of Minnedosa, which in- 
cludes the towns of Basswood, Newdale, Strathclair, and 
Shoal Lake, lies in the Newdale undulating phase. Topogra- 
phy varies from roughly undulating to nearly level. Soils 
are more varied and include black-meadow and degrading 
black-meadow types. Soil drainage is variable. Runoff 
water from the knolls and ridges either accumulates in 
depressions or drains away through meandering, intermit- 
tent channels. 
Climate and Weather 
Weather data before October 1970 were recorded at 
Rivers, Manitoba, about 26 km southwest of the Minne- 
dosa area (Canada Department of Transport 1950-72, 
unpublished data). Thereafter, because weather data were 
no longer available from Rivers, data from 32 km to the 
south, at Brandon, Manitoba, were used. 
The mid-continental climate is characterized by ex- 
tremes, with temperatures ranging from about — 51” to 
36° C. Strong winds are the rule, prevailing from the 
northwest. Long-term average precipitation for the Min- 
nedosa area is 47.6 cm/year. Precipitation was below aver- 
age in 1961, 1966. 1967, and 1972: heavy in 1962. 1965, 
1969. and 1971: and near normal during the other four 
years of the study. 
The severe drought on the Canadian prairies between 
1958 and 1962 also adversely affected the Minnedosa park- 
lands (Fig. 3). According to precipitation trends, the 
1958-62 drought resulted from below normal precipitation 
in 1957-61. Between 1950 and 1972, 58% of the annual 
precipitation occurred during the May-August growing 
season. However, extremes of 9 cm in 1961 and nearly 
40 em in 1962 were recorded during these same months. 
Precipitation in the form of snow from December to March 
was relatively light and averaged only 8.7 em, or 18.5% 
of the mean annual precipitation. 
During the 12 summers of the study, mean precipitation 
was 0.3 cm above the norm, but was below the norm in 
May, June, and August and above the norm in July. Sum- 
mers were wetter than normal in 1962, 1963, 1965, 1968, 
1969, and 1971, and drier than normal in 1964, 1966, 1967, 
