Effect of applying struvite and organic N as recovered fertilizers on the rhizosphere dynamics and cultivation of lupine (Lupinus angustifolius)

Lupine is a legume performing nitrogen-fixing symbiosis with the microbial community. We aimed at characterizing the microbial communities associated with the growing medium, their functionality and their impact on lupine nutrient turnover when either one organic source of nitrogen (amino acids) or an inorganic N source recovered from wastewater treatments (struvite) were applied. Changes in rhizosheath and rhizosphere bacterial communities, as well as pH and nutrient turnover were investigated using rhizotrons. As root architecture is fundamental for plant productivity, clear quantification of root responses to different fertilizer types is a crucial but underestimated tool. Variations in root structure and length as a result of soil nutrient availability driven by plant-bacteria