The response of Whitegrass [Cortaderia pilosa (D'Urv.) Hack.] to nitrogen nutrition |
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| Authors: | F E A Wilson B M R Harvey J H McAdam & D W H Walton |
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| Institution: | Department of Applied Plant Science, Queen's University Belfast, Northern Ireland;Department of Agriculture and Rural Development, Newforge Lane, Belfast, Northern Ireland;British Antarctic Survey, Madingley Road, Cambridge, UK |
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| Abstract: | To investigate the potential for increasing Falkland Island Whitegrass Cortaderia pilosa (D'Urv.) Hack.] pasture production through application of nitrogen (N) fertilizer, two hydroponic experiments were conducted. First, 5 mg l–1 N was supplied to plants as nitrate (NO3–), urea CO (NH2)2], ammonium (NH4+), or a nine parts NH4+: one part NO3– mixture. At harvest, plants grown in a NO3– medium had about half the biomass of plants grown in a NH4+ medium. In the second experiment plants were supplied with 1, 3, 10, 30 or 100 mg l–1 NH4+-N. Plants at 1 and 3 mg l–1 N had the largest biomass of young root and the lowest shoot–root ratios. Leaf extension rate was low in the 1 mg l–1 N treatment. Plants given 10 mg l–1 N had the greatest proportion of green shoot material but little root growth; while those at 100 mg l–1 N produced very little shoot and root biomass. Preferential assimilation of NH4+-N and a low N requirement make Whitegrass well adapted to dominating vegetation on much of the Falkland Islands. |
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| Keywords: | Whitegrass nitrogen nutrition ammonium-N nitrate-N hydroponics |
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