The effect of all combinations of two intensities (3 and 6 cm) and two frequencies (one and four times per year) of defoliation were applied under three different moisture treatments, for the period July 1978 to June 1981, under natural veld conditions. The effect of the moisture and defoliation treatments were evaluated in terms of basal cover, phytomass and water use efficiency (WVE: The phytomass production in relation to the evapotranspiration).
The different moisture treatments caused statistically significant differences in basal cover between the hydrological units, over the three seasons.
Of the variables under consideration, rainfall had the greatest influence on herbage yield. Intensity and frequency of defoliation affected yield to a lesser degree.
The water use efficiency of the grasses in moisture treatment 1 (normal rainfall), increased with a decrease in defoliation intensity. Under optimum soilwater conditions, the water use efficiency of the grasses increased with a increase in defoliation frequency. With a harsher cutting height (3 cm height instead of 6 cm) under optimum water conditions, the water use efficiency also increases.
Journal articles from the Grassland Society of Southern Africa (GSSA) African Journal of Range and Forage Science as well as related articles and reports from throughout the southern African region.