influence of harvest management and fertilizers on herbage yields of cool-season grasses grown in the Aspen Parkland of northeastern Saskatchewan

This study was conducted to evaluate the impact of harvest and fertilizer management on the herbage yield of various grass cultivars grown in the Aspen Parkland region of northeastern Saskatchewan. A series of three experiments were set out: site 1 at Pathlow, Gray Luvisolic soil, 1980; site 2 at Melfort, Deep Black Chernozemic soil, 1979; and site 3 at Pathlow, 1986. At site 1, the design was a split-split plot with fertilizer treatments as mainplots (unfertilized and fertilized, initially with 11N-22P kg ha −1 incorporated 5 cm into soil and thereafter, 50N-13P kg ha −1 broadcast each year). Ten grass cultivars were seeded as subplots and harvest systems as subsubplots (two-cut and four-cut). At site 2 Melfort, the experimental design was similar to site 1, but without the fertilizer treatments. Fertilizer was applied to all plots at the same rates as site 1. At site 3, Pathlow, 14 grass cultivars were seeded with the same experimental design as site 2, but 10 kg S ha −1 was applied each year with the N and P fertilizer. At site 1 Pathlow, the only experiment with the unfertilized control, fertilizer increased the average herbage yield to 2.47 t ha −1 from 1.42 t ha −1 for unfertilized control plots. Frequent cutting (four-cut system) showed reduced annual yields of 1.70, 5.28 and 1.93 t ha −1 compared with 2.19, 7.08, and 2.87 t ha −1 (two-cut system), respectively, for sites 1, 2 (5-yr period) and 3 (7-yr period). A greater response to fertilizer was observed with the 2-cut system, 1.19 t ha −1 , than with the four-cut system, 0.91 t ha −1 , which resulted in a fertilizer × cutting management interaction at site 1. With some exceptions, most of the species were not significantly different in ranking based on herbage yield over the three test sites, but meadow bromegrass [Bromus biebersteinii (Roem & Schult.)] ranked higher in yield on the less fertile Pathlow Gray Wooded soil sites than on the more fertile Melfort Deep Black soil site. Crested wheatgrass (Agropyron cristatum L.) ranked high in herbage yield at all three sites. Crested wheatgrass, smooth bromegrass (Bromus inermis Leyss.) and meadow bromegrass, the most commonly grown species in Saskatchewan, yielded well under the simulated hay and pasture conditions. Other cultivars such as Clarke intermediate wheatgrass [(Elytrigia intermedia (Host) Nevski], Elbee northern wheatgrass [Elymus lanceolatur (Scribn. and Smith)] and Lodorm green needlegrass (Stripa viridula Trin.) should be considered for