Distribution of15N in the soil-plant system during a four-year field lysimeter study with barley (Hordeum distichum L.) and perennial meadow fescue (Festuca pratensis Huds.)
1989 (English)In: Plant and Soil, ISSN 0032-079X, E-ISSN 1573-5036, Vol. 119, no 1, 25-37 p.Article in journal (Refereed) Published
An annual cereal, barley, and a perennial grass ley, meadow fescue, were grown in field lysimeters in Sweden and fertilized with 12 and 20g Ca(NO3)2-N m-2 yr-1, respectively. Isotope-labeled (15N) fertilizer was added during year 1 of the study, whereafter similar amounts of unlabeled N were added during years 2 and 3. The grass ley lysimeters were ploughed after the growing season of year 3 and sown with barley during year 4. The barley harvest in year 1 removed 59% of the added fertilizer N, while the fertilizer N export by two meadow fescue harvests in year 1 was 65%. The labeled N export decreased rapidly after year 1, especially in the barley, but increased slightly after ploughing of the grass ley.
The microbial biomass, measured with the chloroform fumigation method, incorporated a maximum of 1.4-1.7% of the labeled N during the first seven weeks after application. Later on, the incorporation stabilized at less than 1% in both cropping systems.
The susceptibility of the residual labeled N to mineralization was evaluated three years after application by means of long-term laboratory incubations. The curves of cumulative mineralized N were described by a two-component first-order regression model that differentiated between an available and a more recalcitrant fraction of potentially mineralizable N. There was no difference in the amounts of potentially mineralizable N between the cropping systems. The labeled N comprised 5 and 2% of the amounts of potentially mineralizable N in the available and more recalcitrant fraction, respectively. The mineralization rate constants for the labeled N were almost twice as high as for the total potentially mineralizable N. The available fraction of the total potentially mineralizable N was 12%, while twice that proportion of the labeled N was available.
It was concluded that the short-term ley did not differ from the annual crop with respect to the early disposition of the fertilizer N and the behaviour of the residual organic N.
Place, publisher, year, edition, pages
Dordrecht, Netherlands: Kluwer Academic Publishers, 1989. Vol. 119, no 1, 25-37 p.
barley; fertilizer efficiency; leaching; meadow fescue; microbial biomass; nitrate fertilizer; 15N; plant uptake; potentially mineralizable nitrogen
Forest Science Agricultural Science
IdentifiersURN: urn:nbn:se:oru:diva-52230DOI: 10.1007/BF02370266ISI: A1989AR78600004ScopusID: 2-s2.0-0004501002OAI: oai:DiVA.org:oru-52230DiVA: diva2:971192