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Nitrogen Uptake Characteristics of Corn Roots at Low N Concentration as Influenced by Plant Age 1
Author(s) -
Edwards J. H.,
Barber S. A.
Publication year - 1976
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/agronj1976.00021962006800010005x
Subject(s) - nitrogen , zea mays , fertilizer , crop , zoology , chemistry , agronomy , greenhouse , poaceae , horticulture , biology , organic chemistry
Information is needed on the relation between concentration of N in solution, C N , and the rate of N uptake by corn ( Zea mays L.) roots in order to evaluate the soil and crop parameters affecting N fertilizer efficiency. Data on net N influx, I n , vs. C N were obtained for N levels below 150 μM on corn plants of seven ages ranging from 15 to 58 days (2 weeks after tasseling). I n was determined by measuring rate of N depletion from the solution in which corn plants grew. Both NH + 4 and NO ‐ 3 forms of N were used. The experiments were conducted in the growth chamber and greenhouse. Maximum influx, I n‐max , occurred above 21 μM N concentration. Values of I n‐max , varied with plant age and were greatest with 18 to 24‐day‐old plants and decreased exponentially to 58‐day‐old plants. I n ceased when the averaged C N value decreased to 4 μM . This minimum N concentration varied little with plant age. Since the range of C N values where In varied was only 4 to 21 μM, the time period when C N is within this range for corn growing in the field is probably short so I n will usually be at either I n‐max or 0.