Plots of herbaceous vegetation in a natural savanna were treated with various levels and combinations of N P K fertilizer, over a period of four years. Variation between replicate plots was high, both within and between years. This can be ascribed to the spatial heterogeneity of the savanna and the annual variation in rainfall. Results showed that, provided rainfall for the season was not below average, above ground biomass and plant nutrient content responded positively to N P K fertilization, and N and P, in particular. Of the four plant categories examined the palatable grass, Digitaria eriantha, gave the greatest response, resulting in a tenfold increase in protein which would be available to herbivores. Apart from the increase in the biomass of D. eriantha, species composition was unaffected by the fertilizer applications.
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.