Do recent snow events help replenish soil moisture?
The short answer is, yes, melting snow does help replenish soil moisture. However, the amount of water that infiltrates into soil depends on many factors. According to hydrological scientist Phillip Harder, infiltration rate is highest when soil is dry under zero-tillage. On the contrary, saturated soils in fall lead to concrete frost, leading to very limited infiltration. The most common situations exist between the two extremes, where some water infiltrates into soil while others are lost through run off and evaporation.
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On average, though the ratio varies, 25 cm of snow translates to 2.5 cm of rain equivalent. Among the 2.5 cm of rain equivalent, 20 to 50% will become soil moisture available to plants. Between 50 to 80% is lost through runoff and evaporation. The loss is closer to 50% when the topsoil is dry, and up to 80% when surface soil is wet.
Assessing available soil moisture at the start of the season helps setting realistic yield target and planning crop inputs. Alberta research has shown that under good environmental conditions, for each 25 mm (1 inch) of water used, wheat produces 5 to 7 bushels/acre, barley produces 7 to 9 bushels/acre. Refer to Yield Alberta for average yield by crop, class and variety in your region.
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Additional resources:
Current drought conditions – AAFC