Publication Date

1997

Description

The objective of this study was to determine the effects of grazing system and stocking rate on spring profile soil water, soil water extraction and evapotranspiration (ET) of a newly established grass/ legume pasture. The experiment, located on a fine sandy loam soil in western Manitoba, was a two replicate RCBD with continuous and rotational grazing at stocking rates of 1.1 and 2.2 steers/ha. The pastures contained alfalfa (Medicago sativa L.), meadow bromegrass (Bromus biebersteineii Roem and Shult.) and Russian wild ryegrass (Elymus juncea L.). Growing season ET averaged 38.4 cm and was consistently highest for the rotationally-grazed/low stocking rate treatment. Amount of soil water present in spring and the proportion of spring soil water extracted during the grazing season was also highest in the rotationally-grazed/low stocking rate treatment. Higher levels of spring soil water were attributed to greater overwinter water conservation, while greater extraction of available water by the rotationally-grazed/low stocking rate system was attributed to superior root activity. This study showed that grazing management affects soil water conservation and soil water use in dryland pastures in western Canada.

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Water Use in a Newly Established Pasture as Influenced by Grazing Management

The objective of this study was to determine the effects of grazing system and stocking rate on spring profile soil water, soil water extraction and evapotranspiration (ET) of a newly established grass/ legume pasture. The experiment, located on a fine sandy loam soil in western Manitoba, was a two replicate RCBD with continuous and rotational grazing at stocking rates of 1.1 and 2.2 steers/ha. The pastures contained alfalfa (Medicago sativa L.), meadow bromegrass (Bromus biebersteineii Roem and Shult.) and Russian wild ryegrass (Elymus juncea L.). Growing season ET averaged 38.4 cm and was consistently highest for the rotationally-grazed/low stocking rate treatment. Amount of soil water present in spring and the proportion of spring soil water extracted during the grazing season was also highest in the rotationally-grazed/low stocking rate treatment. Higher levels of spring soil water were attributed to greater overwinter water conservation, while greater extraction of available water by the rotationally-grazed/low stocking rate system was attributed to superior root activity. This study showed that grazing management affects soil water conservation and soil water use in dryland pastures in western Canada.