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Changes in the Concentration of Nitrogenous Fractions in Alfalfa Herbage with Advance in Maturity 1
Author(s) -
Lee Chintian,
Smith Dale
Publication year - 1972
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/agronj1972.00021962006400030020x
Subject(s) - asparagine , ammonium , medicago sativa , chemistry , zoology , glutamine , nitrate , agronomy , ammonium nitrate , nitrogen , horticulture , dry matter , amino acid , biology , botany , biochemistry , organic chemistry
Little information is available in which changes in the concentrations of total, protein, nonprotein, ammonium, nitrate:, free α‐amino, asparagine, and glutamine N in alfalfa ( Medicago sativa L.) herbage have been measured at successive growth stages in the same investigation. In the current study, concentrations (% dry weight) of these N fractions were analyzed for the leaflets, stems, and total herbage of ‘Vernal’ alfalfa sampled when the spring growth in 1966 was 25‐, 41‐, and 53‐cm tall, and at first, 25%, and 75% flower. All N fractions decreased in percentage in the leaflets, stems, and total herbage with advance in maturity. Percentages of total N, protein N, and non‐protein N were higher in the leaflets than stems at all stages of growth, while percentages of ammonium N and glutamine N were similar in leaflets and stems. In contrast, percentages of nitrate N, free a‐amino N, and asparagine N were higher in the stems than leaflets. Percentage decreases in the concentration of N f.ractions in the total herbage from the youngest (25‐cm tall) to the oldest (75% flower) stage ranged from a low of 50% for protein N to a high of 75% for nitrate N.