Evaluation of Oxamide as a Slow‐Release Nitrogen Source on Kentucky Bluegrass¹

Abstract

Slow-release N fertilizers are used in turfgrass fertilization programs to reduce foliar burn and N losses, and to extend the response period between applications. In this study, oxamide (31% N), an amide of oxalic acid, and a 7:3 N ratio of oxamide and urea were evaluated as slow release N sources on Kentucky bluegrass (Poa pratensis L.) at West Lafayette, IN, on a Toronto silt loam soil (finesilty, mixed mesic, Udollic Ochraqualfs). Two particle sizes of oxamide, C (1-2.8 mm) and F ( <0.85 mm), were applied as a granular and liquid suspension treatment, respectively. Additional treatments consisted of applying isobutylidene diurea (IBDU), sulfur-coated urea (SCU), and urea. Two and four applications were made, with a total annual application rate of 196 kg N ha~• yr~•. Recovery of N in the tissue from applications of oxamide C was 51% compared to 41, 39, and 38% for IBDU, oxamide F, and SCU, respectively, averaged over 3 yr. Initial change in visual turf quality and clipping yields in response to oxamide C was slow, similar to that of IBDU; however, residual N release was equal to that of IBDU and greater than that of SCU. Adding urea to oxamide C increased initial yields and turf quality but reduced the duration of turf response as compared to applications of oxamide C alone. At two applications of 98 kg N ha~ 1 , oxamide proved to be a good, slow-release source of N. At four applications per year, initial clipping yields resulting from spring oxamide F applications were lower than those from urea, but turf quality in response to residual N tended to be greater than that of urea. Late fall applications of oxamide F reduced soil N03 concentrations shortly after application and in early spring as compared to fall applications of urea. Oxamide F at four applications generally produced a more desirable turf response than did similar applications of urea.Additional index words: Isobutylidene diurea, Sulfur-coated urea, Nitrogen recovery, Soil inorganic nitrogen, Poa pratensis L. Agron. J. 79:720-725 (1987). Published in

Effects of slow-release fertilizers on growth and on uptake and leaching of nutrients in Kentucky bluegrass turfs established on sand-based root zones

“…The N recovery ranged from 43 to 48% when SCU was applied in two splits. A similar trend in N recovery was also reported by Mosdell et al (1987) when SCU was applied in two or four splits at the rate of 196 kg N ha -1 yr -1 . In the present study, about 50% of the applied N through compound NPK was recovered in the clippings.…”

Nutrient distribution across wheat rhizosphere with oxamide and ammonium sulfate as N source

“…Hydrolysis, nitrification and N availability of oxamide affected by the difference in granule diameters were studied by Dement et al (1961). Thereafter, a comparative study on oxamide and ammonium sulfate was carried out by Di1z and Steggerda (1962), while Mosdell et al (1987) and Wehner and Martin (1989) compared oxamide with urea and other fertilizers. Moreover, growth regulating properties of oxamide such as inhibition of ethylene production and of abscission in orange fruits have also been reported (Rehberg 1982).…”