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Apparent Atmospheric Nitrogen Loss from Hydroponically Grown Corn
Author(s) -
Sharpe Ronald R.,
Harper Lowry A.
Publication year - 1997
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/agronj1997.00021962008900040011x
Subject(s) - anthesis , nitrogen , sowing , agronomy , growing season , chemistry , volatilisation , zea mays , field experiment , horticulture , biology , cultivar , organic chemistry
Isotopic 15 N tracers have been important tools in the understanding of N cycling in agricultural and natural soil‐plant systems. The objectives of this research were to quantify losses of 15 N under controlled conditions, evaluate 15 NH 3 transport between plants, and assess the potential for error associated with the use of N isotopes. Corn ( Zea mays L.) was grown hydroponically in 5‐ to 15‐mm‐diam. gravel in twelve 162‐L barrels. All N was applied as NO 3 with enrichment periods of full season, planting through anthesis, anthesis to harvest, or no 15 N applied. Plant growth and total N accumulation followed normal growth curves and maximum N content was obtained at anthesis. When 15 N treatments stopped at anthesis, plants lost 15 N (presumably as 15 NH 3 ) equivalent to about 23% of total plant N between anthesis and harvest. In treatments in which 15 N applications started at anthesis, total N content in the leaves and stems decreased between anthesis and harvest while 15 N content increased indicating a substitution of recently absorbed N for N compounds translocated to the fruit. Volatile losses of N indicate that caution must be exercised when conducting and interpreting 15 N experiments. Significant plant‐to‐plant transport of 15 NH 3 showed that decreases in plant 15 N content could not be used to estimate NH 3 volatilization for an entire field.