NPP Grassland: Towoomba, South Africa, 1949-1990, R1

This data set provides seven data files in text format (.txt). The files provide biomass estimates, soil carbon (C), nitrogen (N), and phosphorus (P) measurements made at an artificially-established grassland savanna study site in Towoomba, South Africa. The study site was part of a long-term experiment to test the effect of fertilizer application. Biomass data are available for the years 1950-1981 (data are not available for 1976 or 1977); soil C, N, and P data are available for the years 1949, 1962, 1980, and 1990. The 1949 estimates were inferred in 1990 from undisturbed savanna adjacent to the experiment.

The savanna-fertilizer experiment was several hectares in extent, with five levels of nitrogen and three levels of phosphorus laid out in a randomized block design on an area from which all trees were removed. The ammonium sulphate and superphosphate fertilizers were added during November (50% of total), January (25%) and February (25%). The response to N fertilizer saturated at higher levels, so data from only six (3 x 2) of the 15 possible treatment combinations are provided.

Above-ground biomass was sampled by mowing to 5-cm height. It was assumed that 50 g/m2 was left in the field, plus an additional 5% of the mowed dry weight.

Revision Notes: Only the documentation for this data set has been modified. The data files have been checked for accuracy and are identical to those originally published.