Growth and Nitrogen Partitioning, Recovery, and Losses in Bermudagrass Receiving Soluble Sources of Labeled 15Nitrogen

Abstract

ADDITIONAL INDEX WORDS. Turfgrass nutrition, Cynodon dactylon 'Tifgreen', photoperiod, irradiance, temperature ABSTRACT. Two greenhouse studies were conducted to trace the fate of fertilizer N in hybrid bermudagrass [Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt-Davy 'Tifgreen'], and to estimate total plant N recovery and losses. The first experiment was performed during winter, with artificial light supplementing natural light to provide a photoperiod of 13.6 to 13.8 hours. The second experiment was conducted during summer and fall under only natural light conditions, with a progressively decreasing photoperiod of 13.7 to 11.1 hours. Urea (UR), ammonium sulfate (AS), and ammonium nitrate (AN) were labeled at 2 atom% 15 N, and applied at N rates of 100 or 200 kg·ha -1 for 84 days (divided into six equal fractions and applied every 14 days). Fertilizer N source did not affect total dry matter (DM) accumulation by the plant components, but the high N rate increased clipping DM production under the longer photoperiod. Under the decreasing photoperiod, overall DM production was reduced, and clipping DM production was unaffected by increased N rate. Average N concentration of clippings varied between N sources, ranging from a high of 38.6 g·kg -1 DM with AS to a low of 34.7 g·kg -1 for UR. In Expt. 1, the greatest total plant N recovery [clippings, verdure (shoot material remaining after mowing), and thatch plus roots] occurred with AS (78.5%) and the lowest with UR (65.9%). In Expt. 2, these values declined to 53.0% and 38.0%, respectively. Urea fertilization resulted in the greatest N losses as a fraction of the N applied (33.6% to 61.5%) and AS fertilization the lowest (20.7% to 46.3%). In view of the greater N losses, UR may be a less suitable soluble N source for bermudagrass fertilization within the conditions of this study. In addition, late-season N fertilization may result in a significant waste of fertilizer N as bermudagrass progresses into autumnal dormancy when temperature, photoperiod, and irradiance decline and cause reduction in growth and N uptake.

Influence of Nitrogen Rate and Form on Quality of Putting Greens Cohabited by Creeping Bentgrass and Annual Bluegrass

“…Reports of improved shoot color (Glinski et al, 1990), shoot growth (Picchioni and Quiroga-Garza, 1999), and/ or NUP (Bailey, 1999;Bloom et al, 1992;Bowman and Paul, 1988) by NH 4 -N fertilization have addressed whole plant responses. Whole-plant studies that directly measured greater NH 4 uptake from NH 4 -N fertilization than NO 3 uptake from NO 3 -N fertilization report either increased (Bailey, 1999;Bloom et al, 1992), indiscernible (Picchioni and Quiroga-Garza, 1999), or decreased root growth response. Bowman and Paul (1988) measured 8% greater perennial ryegrass root mass accumulation with NO 3 -N treatment than by NH 4 -N treatment during the 48-h period immediately following N application.…”

“…3 C. transvaalensis Burtt-Davey cv. Tifgreen] fertilized with (NH 4 ) 2 SO 4 contained 9% more relative N in leaf clippings than bermudagrass fertilized with NH 4 NO 3 (Picchioni and Quiroga-Garza, 1999). Bloom et al (1992) and Bowman and Paul (1988) reported enhanced assimilation of reduced N by barley (Hordeum vulgare L.) and perennial ryegrass (Lolium perenne L.) respectively, when fertilized with NH 4 -N sources compared to NO 3 -N sources.…”

“…Influence of N fertilizer form on nutrient assimilation by species of the Gramineae family is the subject of numerous research investigations; most being conducted in recently established hydroponic or disturbed soil systems, in controlled environments, and over shortduration experimental periods (Bailey, 1999;Picchioni and Quiroga-Garza, 1999;Bloom et al, 1992;Bowman and Paul, 1992;Bowman and Paul, 1988). Results of these studies have been mixed.…”

Growth, Herbage Accumulation, and Nutritive Value of ‘Tifton 85’ Bermudagrass as Affected by Nitrogen Fertilization Strategies

“…Typical N recovery by aboveground plant tissue is generally assumed to be ~50%; however, studying a Cynodon hybrid receiving ammonium nitrate (AN), Impithuksa and Blue (1985) reported much smaller N recovery (15-35%), suggesting that forage N use efficiency likely varies according to soil characteristics, rainfall distribution, and N application level. Conversely, Picchioni and Quiroga-Garza (1999) reported that N losses, measured as 15 N, were not influenced by N fertilizer source and that increased N levels decreased N recovery. Conversely, Picchioni and Quiroga-Garza (1999) reported that N losses, measured as 15 N, were not influenced by N fertilizer source and that increased N levels decreased N recovery.…”

“…In a 3-yr study that evaluated 'Coastal' bermudagrass [Cynodon dactylon (L.) Pers] responses to different N sources on a sandy soil, Burton and Jackson (1962) reported that surface application of AN resulted in 26% greater N recovery than urea. Conversely, Picchioni and Quiroga-Garza (1999) reported that N losses, measured as 15 N, were not influenced by N fertilizer source and that increased N levels decreased N recovery. A similar pattern was also reported by Dillard et al (2015).…”