Interactions between fertilizer nitrogen and soil nitrogen — the so-called ‘priming’ effect

A - Papers appearing in refereed journals

Jenkinson, D. S., Fox, R. H. and Rayner, J. H. 1985. Interactions between fertilizer nitrogen and soil nitrogen — the so-called ‘priming’ effect. Journal of Soil Science. 36 (3), pp. 425-444.

AuthorsJenkinson, D. S., Fox, R. H. and Rayner, J. H.

Experiments with 15N labelled fertilizers often show that plants given fertilizer N take up more N from the soil than plants not given N—the priming effect or ‘added nitrogen interaction’(ANI). This paper is a theoretical study of ANIs and how they can affect the interpretation of experiments with 15N labelled fertilizers. ANIs can be ‘Real’, if for example, fertilizer N increases the volume of soil explored by roots, or ‘apparent’, caused by pool substitution or by isotope displacement reactions. Pool substitution is the process by which added labelled N stands proxy for native unlabelled N that would otherwise have been removed from that pool. Microbial immobilization of N, whether driven by the decomposition of soil organic matter or by the decomposition of plant roots, can lead to pool substitution and is the dominant cause of apparent ANIs. Denitrification and plant uptake of N can also, under special circumstances, lead to pool substitution and thus give rise to apparent ANIs. Isotope displacement reactions, in which the added labelled N displaces native unlabelled N from a ‘bound’ pool, can lead to apparent ANIs but are only likely to be of significance in exceptional circumstances.

The relationship between ANIs, ‘A’ values and N fertilizer uptake efficiencies are examined by means of a simple model for uptake of 15N‐labelled fertilizer by a crop. A positive ‘apparent’ ANI is accompanied by an ‘A’ value that changes as fertilizer applications increase. Likewise, a positive ‘apparent’ ANI also causes fertilizer uptake efficiency to appear lower when measured by the uptake of 15N than when measured by the non‐isotopic ‘difference’ method.

Year of Publication1985
JournalJournal of Soil Science
Journal citation36 (3), pp. 425-444
Digital Object Identifier (DOI)
Open accessPublished as non-open access
Output statusPublished
Publication dates
Print01 Sep 1985
Online28 Jul 2006
Copyright licensePublisher copyright

Permalink -

Restricted files

Publisher's version

Under embargo indefinitely

230 total views
1 total downloads
6 views this month
0 downloads this month