Herbicide-mediated promotion of Lotus tenuis (Waldst. & Kit. ex Wild.) did not influence soil bacterial communities, in soils of the Flooding Pampa, Argentina.

NIEVA, A.S.; BAILLERES M.A.; CORRIALE M.J.; LLAMES M.E.; MENENDEZ A.B.; RUIZ O.A.

APPLIED SOIL ECOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 98 p. 83 - 91

0929-1393

Promoting the forage Lotus tenuis is anappealing alternative to meet the needs for cattle production in the FloodingPampa region, Argentina.  Thisagricultural practice requires herbicides application to remove plant speciescompeting with L. tenuis.  The useof chemical compounds, in addition to the removal of native vegetation, eventuallymay change the diversity of other ecosystem components such as bacterialcommunities. The objectives of this work were to examine the effect of L.tenuis promotion on the bacterial community composition and on specificwater-related soil variables, and to detect specific bacterial taxa respondingto the L. tenuis promotion.  Inorder to achieve these objectives; here we studied three different rangelandsites of the Flooding Pampa region.  Ateach site, two paddocks were compared, one managed to promote the forage legumeL. tenuis, and the other lacking of management history and hence, coveredby natural grasses.  To asses bacterialdiversity we used 454-FLX pyrosequencing technology of the V4 region of the 16SrRNA gene, on genomic DNA extracted from soil samples.  We obtained 135.918 sequences, representing3187 Operational Taxonomic Units (OTUs) distributed in 12 phyla and 45 classes.  Overall, the main identified components ofthe bacterial community at the Phylum level were Acidobacteria, followed byVerrucomicrobia, Planctomycetes and Chloroflexi.  Our results suggest that 5-6 years of land usewith L. tenuis promotion does not affect the microbial communitystructure in this ecosystem. NMDS ordination in two dimensions based onBray-Curtis distances and PERMANOVA test did not show differences in bacterialcommunity composition between paddocks promoted or not with L. tenuis,although differences among sites were detected. In parallel, Pearson´s correlationanalysis suggested that L. tenuis promotion would indirectly affect membersof classes Acidobacteria and Anaerolineae, through altering water-related soilproperties.