Evaluation of Slow-release Nitrogen Rate and Mixing Depth for Growth and Establishment of Kentucky Bluegrass on
Sand-based Systems. (C05-lee745466-poster)
Authors:
S. Lee* - Iowa State University D.D. Minner - Iowa State University N.C. Christians - Iowa State University H. Taber - Iowa State University
Abstract:
Nitrogen (N) is leached easily from sand-based systems resulting in frequent applications. The objective of this study was to determine if high rates of a single application slow-release fertilizer can be loaded into the root zone to facilitate establishment without increasing N loss by leaching. A two-year
greenhouse study was conducted to compare urea and methylene urea at 146 and 293 kg•ha-1 at four mixing depths (0, 7.6, 15.2, and 22.9 cm) on a sand-based system. Results reported are from the first year, 2002. Grass clipping samples were collected every two weeks, dried, and weighed. Root dry weight and organic matter were investigated at the end of the study. Leachate was collected every week and analyzed for nitrate-N (NO3-N) content. The 293 kg•ha-1 rate of methylene urea applied at a depth of 7.6 cm produced 437% more clipping dry weight, 113% more root dry weight, and 101%
more root organic matter than urea at the same treatment level and placement depth. Methylene urea at the 293 kg•ha-1 rate placed at the 22.9 cm mixing depth produced 18 ppm leached NO3-N, whereas urea at that rate and placement depth produced 174 ppm leached NO3-N. With exception of surface application, the results indicate that methylene urea compared to urea alone provided more root and shoot growth for establishment of Poa pratensis L.
Speaker Information: Sang-Kook Lee, Iowa State University, Horticulture Dept., Ames, IA 50011;
Phone: 515-294-6025; E-mail: [email protected]
Session Information: Monday, November 3, 2003, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 719)
Keywords: nutrient; leach; kentucky bluegrass; sand