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Nitrogen concentrations in the cell wall and lignocellulose of smooth homegrass herbage *
Author(s) -
SANDERSON M. A.,
WEDIN W. F.
Publication year - 1989
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1111/j.1365-2494.1989.tb01922.x
Subject(s) - dry matter , bromus inermis , fertilizer , nitrogen , chemistry , nitrification , neutral detergent fiber , zoology , organic matter , agronomy , nitrogen fertilizer , biology , poaceae , organic chemistry
Applying nitrogen (N) fertilizer to grass generally increases N concentration in herbage. Not as well documented, however, are N fertilizer effects on concentrations of N in plant cell walls and lignocellulose. The objective four study was to ascertain how N fertilizer applied with or without a nitrification inhibitor would affect N concentrations in the cell wall (neutral‐detergent fibre (NDF)) and lignocellulose (acid‐detergent fibre (ADF)) of smooth bromegrass (Bromus inermis Leyss). Nitrogen fertilizer ((NH 4 ) 2 SO 4 ) was applied at 0, 125, or 230 kg N ha −1 in combination with 0, 2–5, or 50 kg ha −1 of nitrapyrin (2‐ chloro‐6‐(trichloromethyl) pyridine) to smooth bromegrass in April of 1985 and 1986. Herbage was harvested at 2, 4, 6 and 8 weeks after treatment. Freeze‐dried herbage samples were analysed for in vitro digestible dry matter (IVDDM), total N, and N in neutral‐ and acid‐detergent fibre (NDFN and ADFN, expressed as g kg −1 NDF and ADF, respectively). Nitrapyrin had no effect on IVDDM, total N, NDFN or ADFN, Nitrogen fertilizer increased concentrations of total N in herbage dry matter, and increased N concentrations in NDF and ADF. Most of the increase in total N concentration occurred in the neutral‐detergent soluble portion. When NDFN and ADFN concentrations were expressed on a total N basis (g k g −1 of total N), N fertilizer had no effect. Available fibre N (AFN; calculated as NDFN minus ADFN, each expressed as g kg −1 total N) was not affected by N fertilizer. The average AFN concentration was 93 g kg −1 total N. Nitrogen fertilizer did not affect herbage quality; however, age of herbage had marked effects on herbage quality.