ISSN:
1573-5036
Schlagwort(e):
ammonia
;
barley
;
gaseous nitrogen
;
Hordeum vulgare L.
;
nitrogen balance
;
nitrogen harvest index
;
nitrogen-15 tracer
;
soil nitrogen
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
Notizen:
Abstract The content of soil derived (unlabelled) and fertilizer derived (15N-labelled) nitrogen in the aerial parts of spring sown barley was followed during three growing seasons with widely different climatic conditions. The nitrogen fertilizer was NH4NO3. It was applied annually at four levels (30, 90, 120 and 150 kg N ha−1). The content of fertilizer derived N in the aerial parts of the barley plants was found to attain maximum level about the time of ear emergence. Thereafter it declined. The decline varied from about 5 to 40kg N ha−1. As much as 45% of the fertilizer derived N taken up earlier in the growing period was thereby lost. The content of soil derived N in the aerial parts of the barley plants was independent of the amount of applied N fertilizer and it increased steadily during the whole growing period. Any loss of soil derived N from the tops was therefore more than compensated for by continuous uptake of soil derived N through the roots. The greatest losses of fertilizer derived N took place from plants with a nitrogen harvest index (ratio between grain N content and total shoot N content) below 0.63 at maturity. In contrast, only little nitrogen was lost from plants with a nitrogen harvest index above 0.68 at maturity. The periods of rapid N losses did not coincide with the variation of the rainfall. The cause of the nitrogen loss is discussed and it is suggested that a substantial part of the loss was due to volatilization of ammonia from the aerial parts of the plants.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF02214544
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