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Evapotranspiration and Water Stress of Barley with Increased Nitrogen 1
Author(s) -
Luebs R. E.,
Laag A. E.
Publication year - 1969
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/agronj1969.00021962006100060029x
Subject(s) - evapotranspiration , agronomy , nitrogen , zoology , yield (engineering) , grain yield , leaf area index , water stress , chemistry , horticulture , biology , ecology , materials science , organic chemistry , metallurgy
Nitrogen, equivalent to rates of 45 and 90 kg/ha, applied at emergence, increased the leaf area index of barley 44 and 109%, respectively, before stem elongation. for an 18‐day period before and during tillering, evapotranspiration was 14 and 43% higher with the 45‐ and 90‐kg rates, respectively. During a subsequent 26‐day dry period, available soil water was depleted first at the highest N level. Relative turgidity of barley leaves at the end of the dry period (2 weeks before heading) was 84, 65, and 52% for the 0‐, 45‐, and 90‐kg N rates, respectively. At the high N rate, the number of barley heads per unit land area was reduced 44% and the number of kernels per head, 40%. As a result, barley grain yield was decreased 1,470 kg/ha. In contrast, a yield increase of 450 kg/ha was obtained with the 45‐kg rate of N. These results illutrate how a moderately high rate of N, applied to N‐deficient soil with limited water, can result in severe water stress at a critical growth period and depress grain yield.