%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture non répertoriées par l'AERES
%A Mbengue, M.
%A Fall, S.
%A Diedhiou, I.
%A Cournac, Laurent
%A Clermont Dauphin, Cathy
%T Nitrogen fixation in Vigna unguiculata (L.) Walp. in Senegal is affected by organic input and variety
%D 2025
%L fdi:010097716
%G ENG
%J Innovations Agronomiques
%@ 1958-5853
%K SENEGAL
%K DIOHINE
%P 79-89
%R 10.17180/ciag-2025-vol99-art08-GB
%U https://www.documentation.ird.fr/hor/fdi:010097716
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2026-08/010097716.pdf
%V 99
%W Horizon (IRD)
%X Legumes such as cowpea (Vigna unguiculata), significantly contribute to sustainable agriculture by

offering economic, ecological, and nutritional advantages. A key mechanism behind these advantages is

their capacity to fix atmospheric nitrogen through symbiosis with soil bacteria. This study quantified the

nitrogen fixation of a local and a research-derived cowpea variety intercropped with millet across six

farmers' fields. These fields presented contrasting histories of farmyard manure application. N fixation

was assessed using the natural abundance of 15N method. Interestingly, while the local cowpea variety

obtained a smaller proportion of its nitrogen from the atmosphere (61%), it fixed a considerably larger

amount of nitrogen (40 kg ha-1) and assimilated more total nitrogen (72 kg ha-1) particularly in amended

fields. The substantial increase in nitrogen uptake per unit area, driven by significantly higher biomass

production of the local variety in amended fields, was associated with a trade-off: the cowpea competed

strongly with the intercropped millet, likely for the limited soil water resources. We concluded that organic

input and cowpea variety influenced cowpea nitrogen fixation in these agroecosystems. Farmers typically

sow the local cowpea variety at lower density than tested here, probably to minimize its competition with

millet. The selection of cowpea varieties should therefore balance the goal of limiting cowpea-millet

competition against maximizing cowpea grain and fodder yields.
%$ 076AGRO10 ; 098AGRIC