title: Growth and nitrogen fixation of legumes at increased salinity under field conditions: implications for the use of green manures in saline environments.
abstract: The use of legumes as green manure can potentially increase crop productivity in saline environments and thus contribute to the sustainability of agricultural systems. Here, we present results from a field experiment conducted in the Netherlands that addressed the efficiency of nitrogen (N) fixation by a legume at varying salinities. We grew Melilotus officinalis in an agricultural field using drip irrigation with water salinity varying in electrical conductivity between 1.7 and 20 dS m(-1). In the experiment, nearly 100 % of total plant N in M. officinalis was derived from symbiotic fixation at all but the highest salinity level (20 dS m(-1)). Our results indicated that this species derived substantial amounts of N via symbiotic fixation, the N becoming available in the soil (and thus available to crops) when cultivated legumes senesce and decompose. Based on the growth performance of M. officinalis and its ability to fix N at moderate soil salinity in our field experiments, we identified this species as a promising source for green manure in saline agriculture in temperate regions.
authors: Systems Ecology, Department of Ecological Science, Faculty of Earth and Life Sciences, VU University Amsterdam, Amsterdam, The Netherlands b.bruning@vu.nl.
authors: Bas
authors: B
authors: Bruning
authors: Systems Ecology, Department of Ecological Science, Faculty of Earth and Life Sciences, VU University Amsterdam, Amsterdam, The Netherlands.
authors: Richard
authors: R
authors: van Logtestijn
authors: Systems Ecology, Department of Ecological Science, Faculty of Earth and Life Sciences, VU University Amsterdam, Amsterdam, The Netherlands.
authors: Rob
authors: R
authors: Broekman
authors: Salt Farm Texel, Den Burg, The Netherlands Department of Biological Oceanography, Royal Netherlands Institute for Sea Research (NIOZ), Den Burg, The Netherlands.
authors: Arjen
authors: A
authors: de Vos
authors: Salt Farm Texel, Den Burg, The Netherlands.
authors: Andrés Parra
authors: AP
authors: González
authors: Systems Ecology, Department of Ecological Science, Faculty of Earth and Life Sciences, VU University Amsterdam, Amsterdam, The Netherlands.
authors: Jelte
authors: J
authors: Rozema
keywords: Halophytes; Melilotus officinalis; Sesbania; salinity; symbiotic nitrogen fixation