Seasonal Relationships between Nitrogen Nutrition and Soluble Carbohydrates in the Leaves of Agrostis palustris Huds., and Poa pratemis L.1

Swards of ‘Toronto’ creeping bentgrass ,Agrostic palustris Huds.) and two cultivars of Kentucky bluegrass (Poa pratensis L.), ‘common’ and ‘Merion,’ were fertilized at rates of 0,146, 292, 438, and 584 kg of nitrogen/ha (o, 3, 6, 9, and 12 lb nitrogen/1,0002 ft) per season. The concentrations of five carbohydrates were determined throughout the growing season from leaf tissue of grass plants subjected to these nitrogen (N) treatments. The oligosaccharides, particularly those of higher molecular weight than sucrose, were the sugars most responsive to the N treatments. Oligosaccharides decreased in concentration with increased N treatment. The N treatments did not produce concentraion differenials in the di‐ and monosaccharides. Treatments providing more than 73 kg N/ha (1 ½ lb soluble N/1,0002 ft) per application resulted in equivalent carbohydrate concentrations In the leaf tissue.