ISSN: 0041-3216

ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 60 Number 1
Research Papers
Nitrogen concentration in the major grasses of the Derived and Guinea savanna zones of Nigeria in relation to season and site
Augustine O. lsichei
The concentration of total Kjeldahl N in above- and below-ground grass samples was monitored at five Nigerian savanna sites over 3 years. Significant variation, even in the same species, was found from plot to plot, with the highest concentrations in the samples from early-burnt Derived savanna and the lowest from northern Guinea samples. This may be related to soil N concentrations as a significant positive relationship was found between soil and plant concentrations. Nitrogen concentration in above-ground grass biomass declined almost exponentially from flushing through the dry season, whereas below-ground N concentration increased with the approach of the dry season. Two shade-favouring grasses, Andropogon tectorum and Beckeropsis uniseta were found to have the highest N concentrations above-ground.
Keywords: Nitrogen; Grasses; Nigeria; Savanna