Establishing winterfat in prairie restorations in Saskatchewan

Abstract

The importance of native shrubs in the Northern Mixed Prairie of Canada has generally been overlooked; however, restoration specialists have recognized the importance of including shrubs in prairie restorations. Emergence and establishment of winterfat (Krascheninnikovia lanata (Pursh) A. D. J. Meeuse & Smit), a palatable and long-lived shrub, was evaluated in relation to planting time and seedbed preparation in swards of native grasses that had been seeded on previously cultivated cropland in the prairie ecozone of southern Saskatchewan. Diaspores of winterfat were broadcast at 20 m-2 in autumn or spring on upland and lowland sites in seedbed treatments including (1) a control or undisturbed sward, (2) mowing the sward to a 15-cm height, (3) haying, (4) glyphosate application after haying and, (5) tillage. Emergence of winterfat on upland and lowland sites was about three-fold greater with autumn than with spring planting (P < 0.01). Winterfat establishment on upland sites was affected by the interacting influences of planting times and seedbed treatments (P = 0.01), with most winterfat establishing from autumn sowing in the glyphosate and tillage treatments (2.1 and 2.2 plants m-2, respectively). Establishment of 0.9 plants m-2 from autumn planting was greater (P < 0.01) than the 0.1 plants m-2 establishing from spring sowing on lowland sites. The interaction of planting date and seedbed treatment on lowland sites did not influence winterfat establishment (P = 0.06) nor did seedbed treatments (P = 0.07). Winterfat should be planted in late autumn as opposed to spring. Key words: Ceratoides lanata, Eurotia lanata, Krascheninnikovia lanata, Northern Mixed Prairie, restoration