Herbage productivity and nutritive value of nine grasses in the Peace River region of northwestern Canada
Seasonal production profiles are fundamental to the effective utilisation of herbage crops. In the Peace River region of north-western Canada, the seasonal productivity and nutritive value of the primary growth of nine grasses was assessed under conditions of potentially non-limiting N fertiliser (1...
| Published in: | Canadian Journal of Plant Science |
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| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
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Canadian Science Publishing
2004
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.4141/p02-094 http://www.nrcresearchpress.com/doi/pdf/10.4141/P02-094 |
| Summary: | Seasonal production profiles are fundamental to the effective utilisation of herbage crops. In the Peace River region of north-western Canada, the seasonal productivity and nutritive value of the primary growth of nine grasses was assessed under conditions of potentially non-limiting N fertiliser (150 kg N ha -1 ). Yield, digestibility and N concentration of dry matter (DM) were determined for herbage harvested at six dates during primary growth (late-May to mid-August at 2-wk intervals), and regressed on time in the growing season. Herbage DM yield increased exponentially throughout primary growth for each grass although the nature of the relationship differed among the grasses, both with respect to the maximum yield and the amount of early-season production; maximum yields ranged from 3.61 t ha -1 for reed canary to 6.31 t ha -1 for intermediate wheat. The early-season productivity of meadow foxtail and crested wheat was particularly evident, with DM yields in excess of 1 t ha -1 by 24 May compared to less than 0.32 t ha -1 for the other seven grasses. Reed canary and meadow foxtail had high N concentrations, meadow brome and three wheatgrasses had low N concentrations, and smooth brome, timothy and creeping red fescue had intermediate N concentrations. Herbage digestibility during the primary growth could be characterised by a single response curve for the nine grasses; digestibility decreased exponentially during the vegetative to head-emergence stage of growth at an average rate of 4.1 g kg -1 DM d -1 , from 830 g kg -1 DM in late-May to 616 g kg -1 DM in mid-July. Herbage N concentration and digestibility were related linearly for each of the nine grasses. Key words: Grasses, herbage, yield, nutritive value, primary growth |
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