Reaction of three veld grasses to different schedules of grazing and resting. 2. Residual effects on vigour
作者:
BarnesD.L.,
期刊:
South African Journal of Plant and Soil
(Taylor Available online 1989)
卷期:
Volume 6,
issue 1
页码: 8-13
ISSN:0257-1862
年代: 1989
DOI:10.1080/02571862.1989.10634472
出版商: Taylor&Francis Group
关键词: Grazing;non-structural carbohyrates;resting;root mass;vigour
数据来源: Taylor
摘要:
Seven defoliation treatments involving grazing at intervals with sheep until mid-January or mid-March, or for the whole growing season at each of two stocking intensities, or resting for the whole growing season (control treatment) were applied on veld during the 1985–86 growing season. Residual effects of the treatments on root mass and the mass of non-structural carbohydrates (NSC) in the roots of populations of the three most abundant grass species,Heteropogon contortus, Themeda triandraandTrachypogon spicatuswere determined in the winter of 1986. Shoot yields in the 1986–87 growing season were measured by harvesting species separately on both a tuft basal area and quadrat basis. In general, the defoliation treatments resulted in marked reductions in root and NSC mass in all species as compared with the control. Residual effects on shoot yields were relatively small, and, in sharp contrast to previous findings, correlations between effects on roots and on shoot yields were, except in the case ofTrachypogon, generally poor. Discrepancies were found between the residual effects on shoot yields of species measured on a per unit tuft basal area or a quadrat basis. The implications of such discrepancies are discussed.
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