Nitrogen allocation of three turfgrass species and turf-type buffalograss management

Environmental concerns about reducing the amount of chemicals and water applied to turfgrass have resulted in interest in using buffalograss [ Buchloe dactyloides (Nutt.) Engelm] as a turfgrass. Buffalograss has commonly been cited as having minimal response to nitrogen applications but nitrogen use in the species has riot been thoroughly investigated. Research was conducted to compare nitrogen allocation among Kentucky bluegrass ( Poa pratensis L.), tall fescue (Festuca arundinacea Schreb.), and buffalograss and to determine nitrogen rate and mowing height effects on buffalograss. Double-labeled ammonium nitrate with 5% 15N enrichment was applied at 24 and 49 kg N ha−1 to Kentucky bluegrass and tall fescue and at 49 and 98 kg N ha−1 to buffalograss to determine nitrogen allocation in verdure, thatch, roots, and soil. For the buffalograss cultivars, the soil accounted for the largest percent of nitrogen recovered from fertilizer and for Kentucky bluegrass and tall fescue the thatch layer and soil accounted for the largest percent of nitrogen recovered from fertilizer. The average total nitrogen recovery in Kentucky bluegrass and tall fescue at the 24 and 49 kg N ha−1 rates was 95 and 73%, respectively. The average total nitrogen recovery in the buffalograss cultivars at the 49 and 98 kg N ha−1 rates was 51 and 31%, respectively. Low nitrogen recovery in buffalograss indicated potentially significant volatilization and denitrification losses. Nitrogen was applied at 0, 24,49, 98, and 195 kg N ha−1 and mowing heights of 2.5, 5.0, and 7.5 cm were imposed on four buffalograss cultivars at sites in Nebraska, Kansas, and Utah to determine nitrogen rate and mowing height effects. Significant nitrogen rate x year interactions revealed that the 98 kg N ha−1 rate sustained quality, while lower nitrogen rates did not. For NE 91-118 turfgrass; quality was best at the 2.5 and 5.0 cm mowing height, 378 performed well at all mowing heights and ‘Cody’ and ‘Texoka’ were best at the 5.0 and 7.5 cm mowing height