Crop rotation associating a legume and the nickel hyperaccumulator Alyssum murale improves the structure and biofunctioning of an ultramafic soil

• Published in: Ecological research 2018-07, Vol.33 (4), p.799-810
• Main Authors: Saad, Ramez Farajallah, Kobaissi, Ahmad, Machinet, Gaylord, Villemin, Geneviève, Echevarria, Guillaume, Benizri, Emile
• Format: Article
• Language: English
• Subjects: Agricultural practices; Agromining; Agronomy; Alyssum murale; Behavioral Sciences; Bioavailability; Biomedical and Life Sciences; Chemical analysis; Controlled conditions; Crop rotation; Ecology; Environmental Sciences; Evolutionary Biology; Fertility; Forestry; Heavy metals; Legume; Legumes; Life Sciences; Nickel; Nitrogen enrichment; Organic chemistry; Plant Sciences; Rotation; Shoots; Soil; Soil analysis; Soil chemistry; Soil fertility; Soil fractionation; Soil improvement; Soil structure; Soils; Special Feature; Ultrastructural characterization; Zoology
• ISSN: 0912-3814; 1440-1703
• DOI: 10.1007/s11284-017-1526-4

N ickel (Ni) agromining aims to phytoextract heavy metals using hyperaccumulators whilst at the same time rehabilitating ultramafic soils. After removing the bioavailable metal, ultramafic soils are improved in terms of their agronomic properties with the aim of future agricultural uses. The low fertility of ultramafic soils can be compensated by integrating legumes already used in traditional agro-systems because of their importance in soil nitrogen enrichment. However, few studies have evaluated the potential profits of legumes on Ni agromining and their potential benefits on soil biological fertility. Here, we characterized the effect of a crop rotation with two plants, a legume ( Vicia sativa ) and a hyperaccumulator ( Alyssum murale ), on the phytoextraction efficiency and on soil structure and biofunctioning. A pot experiment was set up in controlled conditions to grow A. murale and four treatments were tested: rotation with V. sativa ( Ro ), fertilized mono-culture ( FMo ), non-fertilized mono-culture ( NFMo ) and bare soil without plants ( BS ). No significant difference was found between the Ro and NFMo treatments for the dry biomass yield. However, the Ro treatment showed the highest Ni concentrations ([Ni]) in A. murale shoots compared to FMo and NFMo treatments. The Ro treatment plants had more than twice as many leaves [Ni] compared to FMo . Soil physico-chemical analyses showed that the Ro treatment was better structured and showed the highest presence of bacterial micro-aggregates, as well as less non-aggregated particles. Legumes integration in Ni-agromining systems could be a pioneering strategy to reduce chemical inputs and to improve soil biofunctioning and thus fertility.