INGEBI   02650
INSTITUTO DE INVESTIGACIONES EN INGENIERIA GENETICA Y BIOLOGIA MOLECULAR "DR. HECTOR N TORRES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Monocropping drives the homogenization of bacterial communities at a regional scale in no-till fields of Argentinean pampas
Autor/es:
FIGUEROLA, E.L.M.; GUERRERO, L.D.; TÜRKOVSKY, D.; WALL, L.G.; ERIJMAN, L.
Lugar:
Braunschweig
Reunión:
Congreso; 2nd Thünen Symposium on Soil Metagenomics; 2013
Resumen:
Previous studies focusing on local diversity were unable to grasp any deleterious effects of monocropping on soil bacterial communities. In opposition, variation of beta-diversity at a regional scale can provide insights into the importance of habitat conditions in structuring the communities. Objectives The aim of this work was to uncover the response of soil bacterial communities to monocropping in comparison to high crop rotation in no-till production fields. Blocks of treatments were sampled at 4 different locations across a scale of 400 km along 3 successive cropping seasons. In each location we sampled a natural field (grassland) and two production fields managed under no-till according to the following standards: 1) Crop rotations and appropriate nutrient amendment, 2) Soybean monoculture and minimal nutrient inputs. Three replicates from the top 10 cm of bulk soil separated 50 m from each other were taken for each treatment, site and time, making a total of 108 samples. The Mothur and QIIME pipelines were used to process and analyze the reads of the bar-coded 454 sequencing of the V4 region of the 16S rRNA. A total of 333180 OTUs averaging 254 bp were used for analysis. There were no significant data differences in alpha-diversity related to sites or soil management. However, histograms of pairwise distances between all pairs of samples within treatments (weighted Unifrac, Fig 1) revealed that beta-diversity was reduced and had narrower breadth in monocropping agriculture than in grassland soils while fields under crop rotations was in between. At the phylum level the magnitude of this effect depended on the richness of each taxon at the regional scale. In conclusion, crop monoculture drive the homogenization of bulk soil bacterial communities across a regional scale. Variation in taxa responses to agricultural management could be explained by differences in gamma diversity.