Nitrogen concentrations in field-grown spring barley: an examination of the usefulness of expressing concentrations on the basis of tissue water

A - Papers appearing in refereed journals

Leigh, R. A. and Johnston, A. E. 1985. Nitrogen concentrations in field-grown spring barley: an examination of the usefulness of expressing concentrations on the basis of tissue water. The Journal of Agricultural Science. 105 (2), pp. 397-406.

AuthorsLeigh, R. A. and Johnston, A. E.
Abstract

A study was made of growth and N concentrations of field-grown crops of spring barley (Hordeum vulgare L. cv. Georgie or Triumph). Nitrogen concentrations were calculated on the basis of both dry matter and tissue water because previous research had indicated that K concentrations expressed on the basis of tissue water were better for assessing the K status of crops. The aim was to see whether this was also the case for N.
When supplies of P and K were adequate, the addition of N fertilizer stimulated growth in all crops except when sufficient N was already supplied as farmyard manure. Percentage N in dry matter declined as plants grew and was higher in plants given N than in plants grown without N, although the difference diminished with time. Nitrogen concentrations calculated on the basis of tissue water were very similar for both N-sufficient and N-deficient crops despite large differences in growth rates. Nitrogen concentrations in tissue water also declined but only until anthesis, thereafter they increased. This pre-anthesis decline was due to the increase in the amount of stem tissue which had lower N concentrations in tissue water than leaves. Similarly the post-anthesis increase in N concentrations was due to the development of the ears which had high concentrations of N in tissue water.
The effects of deficiencies of P or K or water on N concentrations in tissue water of the cultivars Georgie or Julia were studied also in field experiments at Rothamsted. Lack of P and K inhibited growth of crops given 144 kg N/ha. Crops grown without N grew more slowly than those given N but their growth was not further inhibited by lack of P or K. Deficiencies of either P or K increased N concentrations calculated on the basis of tissue water in crops given 144 kg N/ha but not in crops grown without N. The increase in concentration was not due to changes in the proportions of leaves and stems but to real increases in N concentrations in leaves, stems and ears. Drought decreased growth and also resulted in higher N concentrations in tissue water.
In the absence of other limiting factors, N concentrations expressed on the basis of tissue water were very similar for both N-sufficient and N-deficient crops. They increased only when growth was limited by factors other than N. The implications of this for the control of N concentrations by crops is discussed.
It is concluded that N concentrations expressed on the basis of tissue water are unlikely to be useful for determining the N requirements of barley. Percentage N in dry matter might be more useful for this purpose.

Year of Publication1985
JournalThe Journal of Agricultural Science
Journal citation105 (2), pp. 397-406
Digital Object Identifier (DOI)doi:10.1017/S0021859600056458
Open accessPublished as non-open access
Publication dates
PrintOct 1985
PublisherCambridge University Press (CUP)
ISSN0021-8596

Permalink - https://repository.rothamsted.ac.uk/item/8wq1x/nitrogen-concentrations-in-field-grown-spring-barley-an-examination-of-the-usefulness-of-expressing-concentrations-on-the-basis-of-tissue-water

Restricted files

Publisher's version

Under embargo indefinitely

4 total views
2 total downloads
0 views this month
0 downloads this month