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Modeling Tall Fescue Cultivar Response to Applied Nitrogen
Author(s) -
Overman Allen R.,
Wilkinson Stanley R.
Publication year - 1993
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1993.00021962008500060012x
Subject(s) - festuca arundinacea , cultivar , dry matter , forage , agronomy , mathematics , festuca , endophyte , nitrogen , biology , poaceae , botany , chemistry , organic chemistry
Models can be used to estimate yields and nutrient utilization by forage grasses. The objective of this study was to model response of three cultivars of tall fescue ( Festuca arundinacea Schreb.) to applied N over a 3‐yr period at Watkinsville, GA. The procedure uses analysis of variance to evaluate linear parameter A and the exponential parameters b and c for the logistic equation. It was shown that yields could be averaged across years and that all differences among cultivars could be assigned to the b (intercept) parameter. ‘All‐Triumph’ proved to be more efficient at converting soil N to dry matter without applied N than either ‘Johnstone’ or ‘Kentucky 31’ cultivars. Endophyte ( Acremonium coenophialum Morgan‐Jones & Gams) infection did not affect dry matter response relationships of Kentucky 31. Maximum incremental conversion of applied N to dry matter occurred at N = 125 kg ha −1 , where plant N utilization was ≈80%. The logistic model provides a very useful tool for evaluating response of tall fescue cultivars to applied N.