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Effects of Nitrogen Fertilization on a Chinese Cabbage Hybrid
Author(s) -
Guillard K.,
Allinson D. W.
Publication year - 1988
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/agronj1988.00021962008000010005x
Subject(s) - loam , human fertilization , dry matter , agronomy , nitrogen , forage , growing season , brassica rapa , field experiment , biology , zoology , brassica , nitrogen fertilizer , chemistry , fertilizer , soil water , ecology , organic chemistry
Brassica spp. may be used advantageously during forage‐deficit periods, particularly for late‐season grazing in the northern USA. This study evaluated the influence of N fertilization on the yield and N metabolism and distribution in ‘Tyfon’ [ B. rapa L. × B. pekinensis (Lour.) Rupr.], a Chinese cabbage hybrid. Field experiments were conducted in August through November of 1983 and 1984 on a Woodbridge fine sandy loam soil (coarse‐loamy, mixed, mesic Aquic Dystrochrept). Tyfon was no‐till seeded into a herbicide‐suppressed sod, followed by broadcast N at rates of 0, 56,112,168, and 224 kg ha −1 . Foliage yields, N uptake, and concentrations of total N and NO 3 −N increased with applied N. Root yields, concentrations of dry matter, and N use efficiencies were reduced as N rate increased. The amount of N partitioned into the foliage was much greater than in the roots. Once total N uptake reached approximately 100 kg ha −1 , no significant increases in yield were observed. Total N recovery, averaged over years, exceeded 75% at the 56 to 168 kg N ha −1 treatments. These data suggest that N fertilization of Tyfon is beneficial only when the amount of N available to plants results in N uptakes of less than 100 kg ha −1 . Excessive N fertilization is accompanied by accumulation of NO 3 –N in the plant.