title: Microbial response to salinity stress in a tropical sandy soil amended with native shrub residues or inorganic fertilizer.
abstract: Soil degradation and salinization caused by inappropriate cultivation practices and high levels of saltwater intrusion are having an adverse effect on agriculture in Central Senegal. The residues of Piliostigma reticulatum, a local shrub that coexists with crops, were recently shown to increase particulate organic matter and improve soil quality and may be a promising means of alleviating the effects of salinization. This study compared the effects of inorganic fertilizer and P. reticulatum residues on microbial properties and the ability of soil to withstand salinity stress. We hypothesized that soils amended with P. reticulatum would be less affected by salinity stress than soils amended with inorganic fertilizer and control soil. Salinity stress was applied to soil from a field site that had been cultivated for 5 years under a millet/peanut crop rotation when microbial biomass, phospholipid fatty acid (PLFA) community profile, catabolic diversity, microbial activities were determined. Microbial biomass, nitrification potential and dehydrogenase activity were higher by 20%, 56% and 69% respectively in soil with the organic amendment. With salinity stress, the structure and activities of the microbial community were significantly affected. Although the biomass of actinobacteria community increased with salinity stress, there was a substantial reduction in microbial activity in all soils. The soil organically amended was, however, less affected by salinity stress than the control or inorganic fertilizer treatment. This suggests that amendment using P. reticulatum residues may improve the ability of soils to respond to saline conditions.
authors.affiliation: Université Gaston Berger, UFR des Sciences Agronomiques de l'Aquaculture et des Technologies Alimentaires, B.P. 234 Saint-Louis, Senegal. Electronic address: saidou-nourou.sall@ugb.edu.sn.
authors.forename: Saïdou Nourou
authors.initials: SN
authors.lastname: Sall
authors.affiliation: ISRA Laboratoire National de Recherche sur les Productions Végétales, Centre ISRA/IRD Bel-Air, B.P. 2312 Dakar, Senegal.
authors.forename: Ndèye Yacine Badiane
authors.initials: NYB
authors.lastname: Ndour
authors.affiliation: Université Assane Seck, Département Agroforesterie, B.P. 523 Néma, Ziguinchor, Senegal.
authors.forename: Siré
authors.initials: S
authors.lastname: Diédhiou-Sall
authors.affiliation: School of Environment and Natural Resources, 2021 Coffey Road, Ohio State University, Columbus, OH 43210, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Dick
authors.affiliation: UMR 210 Eco&Sols (Ecologie Fonctionnelle & Biogéochimie des Sols) INRA-IRD-SupAgro, Place Viala (Bt. 12), F-34060 Montpellier Cedex 1, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Chotte
mesh_terms: D000383:Agriculture / Q000379:methods*; D018533:Biomass; D018556:Crops, Agricultural; D007887:Fabaceae / Q000737:chemistry; D005227:Fatty Acids / Q000032:analysis; D005308:Fertilizers; D059013:Microbial Consortia / Q000502:physiology*; D010743:Phospholipids / Q000032:analysis; D054712:Salinity; D012675:Senegal; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D014329:Tropical Climate
chemical_list: D005227:Fatty Acids; D005308:Fertilizers; D010743:Phospholipids; D012987:Soil
keywords: Microbial activity; Piliostigma reticulatum; Resistance; Salinity; Soil management