ISSN 2756-3863
International Journal of Manures and Fertilizers ISSN 2756-3863 Vol. 9 (4), pp. 001-005, April, 2021. © International Scholars Journals
Full Length Research Paper
Appraisal of the 15N-isotope dilution and 15N natural abundance methods for quantifying nitrogen fixation by flood-tolerant green manure legumes
Eklou A. Somado1* and Ronald F. Kuehne2
1Africa Rice Center (WARDA), 01 Bp 2031 Cotonou, Benin Republic.
2University of Goettingen, Department of Crop Science, Tropical Agronomy Division, Grisebachdtr. 6, D-37077 Goettingen Germany.
Accepted 12 January, 2021
Abstract
Quantification of biological nitrogen fixation (BNF) is fundamental to identifying potential green manure legumes for their enhanced nitrogen contribution to sustained crop production. A screenhouse experiment compared BNF by Aeschynomene afraspera L. as affected by phosphorus, using the 15N-isotope dilution and the 15N methods. Rice ( Oryza sativa L.) was grown as a non -fixing plant. Phosphorus significantly increased the percent N derived from the atmosphere (% Ndfa), whereby the 15N method tended to overestimate BNF contribution on average by 20% compared to the 15N dilution. Data confirmed rice as a non-fixing plant for estimation of BNF by flood-tolerant legumes.
Key words: Aeschynomene afraspera, Biological nitrogen fixation, 15N-isotope dilution, 15N natural abundance.