The effects of nitrogen fertility on the performance of “Port Harcourt grass”, Chrysopogon aciculatus (Retz.) Trin. were assessed with the aim of determining the optimum N rate for the turf quality features. Six fertilization regimes of 10, 20, 30, 40, 50, 60 g nitrogen/m2/month and control were set up in three replicates each. “Port Harcourt grass” established from tillers were allowed to grow for four weeks before data collection started. Data were collected on ground cover, chlorophyll index and concentrations, total carotenoids, clipping yield and biomass at maturity. Fertility rate of 30 g N/m2 was optimal for ground cover at weeks after planting but a lower rate (20 g N/m2) was required after clipping. Fresh weights at second clipping and aboveground biomass were higher in the fertilizer treatments, but the corresponding dry weights were not affected. Higher N rates up to 60 g N/m2 enhanced chlorophyll index, chlorophyll a, chlorophyll b and total carotenoids at the fourth week after second clipping. Soil N correlated positively with ground cover. Above- and below-ground biomasses also correlated positively. Chlorophyll index correlated positively with chlorophylls a and b. Chlorophyll a correlated positively with chlorophyll b and total carotenoids. The study concluded that fertility rates influence turf quality characteristics differently and the positive correlation between some of the quality characteristics shows the possibility of achieving improvement of the qualities with the same treatment.
Key Words: Fertility, Growth, Nitrogen, Performance, Port Harcourt grass, Turf