Full TGIF Record for: 36414 |
| Monographic Author(s): | Miltner, Eric David |
| Author Affiliation: | Michigan State University |
| Item is a: | Dissertation |
| Monograph: | Distribution and Cycling of ¹5N-Labeled Urea in a Kentucky Bluegrass Turf, 1994. |
| # of Pages: | 163 |
| Publishing Information: | Ph.D. Dissertation: Michigan State University |
| Collation: | xiv; 149 pp. |
| Keywords: | Urea; Leaching; Fate; Fall fertilization; Nitrogen mineralization; Poa pratensis; Nitrogen fate |
| Abstract: | "The fate of ¹5N-labeled urea applied to Kentucky bluegrass (Poa pratensis L.) turf was studied using intact monolith lysimeters. Soil type was a Marlette fine sandy loam (fine-loamy, mixed mesic Glossoboric Hapludalfs). Lysimeters were used only for the collection of leachate. PVC microplots were installed for destructive soil sampling. Urea was applied at a rate of 196 kg N ha-¹, based on two application schedules. The 'Spring' treatment was fertilized at approximately 38 day intervals from late April through late September. The 'Fall' treatment was fertilized from early June through early November. In 1991 only, the April and November applications were made with ¹5N-labeled urea (25 atom % excess). For the Spring treatment, 35% of the LFN was harvested in clippings over two years. Approximately 30% of LFN was recovered from thatch 18 days after treatment (DAT). This
value remained constant for the next year, then declined. Only 8% of the LFN was recovered from soil 18 DAT. This increased to 14% two years after application. Over the two year period, LFN in leachate totaled 0.09 kg ha -¹. For the Fall treatment, 38% of the LFN was harvested in clippings over two years. Eighteen days after the November application 62% of the LFN was recovered from thatch. This value declined to 35% by the following June. LFN in soil increased from 12% to 25% over two years. Leachate LFN totaled 0.07 kg ha-¹ over the two year period. Volatile losses of N were suspected for both treatments, but a subsequent experiment to measure this was inconclusive. Two years following the application of LFN, soils were incubated to determine N mineralization rates. Over 50 days, 46.1 kg N ha -¹ was mineralized from the surface 10 cm of soil, of which 0.40 kg ha -¹ was LFN.
Addition of N as either NH4+ or grass clippings induced a priming effect on the turnover of soil N. The results of these experiments showed that the thatch layer and microbial biomass played extremely important roles in immobilization of LFN. Mineralization of organic N provides a significant source of N available for plant uptake. Application of fertilizer N to turfgrass results in very little leaching potential, even when applied in late Fall." |
Library of Congress
Subject Headings: | Kentucky bluegrass |
| Language: | English |
| References: | 60 |
| Note: | Ph.D. Dissertation: Michigan State University |
| Note: | Includes list of tables; ix-xi |
| Note: | Includes list of figures; xii-xiv |
| Note: | Includes appendix; pp. 137-144 |
| Note: | Tables |
| Note: | Graphs |
| | ASA/CSSA/SSSA Citation (Crop Science-Like - may be incomplete):
Miltner, Eric David 1994. Distribution and Cycling of ¹5N-Labeled Urea in a Kentucky Bluegrass Turf. Ph.D. Dissertation: Michigan State University. |
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