Impact of rhizobial inoculation and reduced N supply on biomass production and biological N₂ fixation in common bean grown hydroponically

Abstract

Rt inoculation of hydroponic bean provides no advantage when full-N NS is supplied, while 1/3 of full-N or N-free NS suppresses plant biomass and yield, partly because the restricted NO supply impairs cation uptake. © 2017 Society of Chemical Industry.

Improving the Fertigation of Soilless Urban Vertical Agriculture Through the Combination of Struvite and Rhizobia Inoculation in Phaseolus vulgaris

“…The lower nodule dry weights in the control treatment, compared to treatments A and B, have previously been reported in other studies, in which the nodule fresh and dry weights were found to be considerably reduced when inorganic NO 3 – fertilization was not restricted ( Nanjareddy et al, 2014 ; Kontopoulou et al, 2017 ). On the other hand, other authors report that the nodule number was not affected when exposing the crop to mineral and organic N sources but rather affected in size and weight ( Pampana et al, 2017 ).…”

“…The increasing nodule numbers and weights throughout the experiment for the B treatment (with greater struvite), when compared to treatment A, confirm Kontopoulou et al (2017) . findings that low initial N fertilization can restrict successful colonization.…”

“…The “B” value is the isotopic fractionation observed in N 2 -fixing P. vulgaris was set to –1.16‰, which corresponded to the lowest δ 15 N value obtained ( Shearer and Kohl, 1989 ; Peoples et al, 2002 ; Kermah et al, 2018 ) and was similar to the values determined by Kontopoulou et al (2017) in common bean that was fertilized without N and inoculated with Rhizobium.…”

“…Rhizobium as a second source of N was chosen due to the lower inputs needed to achieve nitrogen intake by plants ( Gopalakrishnan et al, 2015 ). When using the N 2 -fixing bacterium, Rhizobium, in hydroponic cultivation, Kontopoulou et al (2017) described the need to apply initial N fertilization until nodulation in the root medium occurs, to further encourage nodulation and therefore N fixation, plant growth, and production. Even though previous studies have reported lower production capacities for N 2 -fixing plants than for common beans with N fertilization ( Olivera et al, 2004 ; Kontopoulou et al, 2017 ), a combination of the two N sources (e.g., struvite and N 2 -fixing bacteria) was used to determine the possibility of overcoming such lower yields ( Pampana et al, 2017 ; Savvas et al, 2018 ).…”

Enhancing legume growing through sustainable cropping for protein supply

“…Since the future competitiveness of the grain legumes value chain in Europe will depend on agronomic and scientific developments, for this In Focus issue of the Journal of the Science of Food and Agriculture we gathered relevant papers covering novel research addressed by the multidisciplinary teams of the EUROLEGUME project, with the aim of bringing added value to the grain legume chain.…”