The influence of different forms and concentrations of nitrogen on the growth and metabolism of Digitaria eriantha and Chloris gayana grown under saline conditions.

Abstract

Reports the results of a study conducted to compare the growth and total reduced nitrogen content of the above ground components of Digitaria eriantha and Chloris gayana plants grown in saline conditions and supplied with different levels of nitrogen in the form of nitrate and ammonia; Chloris gayana and Digitaria eriantha plants were watered with nutrient media containing a high concentration of sodium chloride (150mM) and either high (200mg/l) or low (25mg/l) concentrations of nitrate nitrogen and ammonium nitrogen. Dry mass and leaf area production as well as the total reduced nitrogen content of the above ground components were promoted when higher levels of nitrogen, particularly the nitrate form, were applied. As expected the halophytic grass Chloris gayana was able to produce higher levels of dry matter when it was grown in saline conditions compared to Digitaria eriantha under equally saline conditions.

Keywords: ammonia; Ammonium nitrogen; Chloris gayana; Digitaria eriantha; Dry mass; dry matter; Grasses; Growth; Leaf area; Metabolism; nitrate; Nitrate nitrogen; Nitrogen; Nitrogen concentrations; Nitrogen forms; nutrient medium; Saline conditions; Sodium chloride; Total reduced nitrogen

Journal of the Grassland Society of Southern Africa.