here - First Legume Society Conference (LSC1)

Book of Abstracts First Legume Society Conference 2013: A Legume Odyssey Novi Sad, Serbia, 9-11 May 2013
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Biological Nitrogen Fixation (BNF) by faba bean at the centre for sustainable cropping
(CSC), Dundee, Scotland
Euan K James, Pietro PM Iannetta, Laura Lopez del Egido, Sarah Doherty, Mark Young, Cathy
Hawes, Geoff Squire
Ecological Sciences, The James Hutton Institute, Invergowrie, Dundee, UK
Faba beans are widely grown in East Scotland, but little is known about their capacity for BNF
under these conditions. We therefore used the 15 N natural abundance technique to measure BNF
by 5 varieties of faba beans in a rotation at the CSC under conventional (i.e. a “normal” dressing
of N free fertiliser) and “sustainable” (compost-fertiliser) regimes. Using non-legume dicot weeds
as non-fixing references, the %N derived from air (%Ndfa) at early- to mid-pod fill for all
varieties combined was estimated as over 80% for the sustainable, and slighly less for the
conventional fertiliser treatments in the years examined (2011, 2012). At final harvest, estimates
of the total amount of grain N fixed under each regime did not differ between the sustainable
and conventional split-field halves at over 180 kg N ha -1 yr -1 . However, there were significant
differences between varieties in terms of BNF when grown under the two regimes. In addition,
the amount of fixed N remaining in the non-grain material (i.e. shoots and roots) at final harvest
was up to 100 kg N ha -1 yr -1 , depending on treatment and variety. It is concluded that under a
zero applied N regime, faba beans may obtain a very high proportion of their N-requirements via
BNF in East Scotland, and that it may be possible to optimise the amount of N fixed by
matching faba bean varieties to particular fertiliser regimes.
Acknowledgements
This work is supported by EU FP7 Legume Futures (http://www.legumefutures.eu/).
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