INVESTIGADORES
MARTINEZ Juan Manuel
congresos y reuniones científicas
Título:
A COMPREHENSIVE APPROACH IN THE SEARCH OF MICROBIAL INDICATORS ASSOCIATED WITH DIFFERENT AGRICULTURAL PRACTICES UNDER NO-TILL MANAGEMENT
Autor/es:
GUERRERO L.; AGARAS B.; REYNA D.; GABBARINI G.; DUVAL M.; MARTINEZ JUAN MANUEL; FIGUEROLA E.; FERRARI A.; VALVERDE C.; GALANTINI J.A; ERIJMAN L.; WALL L.
Lugar:
Seattle
Reunión:
Simposio; 13th International Symposium on Microbial Ecology; 2010
Institución organizadora:
Microbes Stewards of a Changing Planet
Resumen:
We present the first results of an interdisciplinary
project (BIOSPAS) aimed at understanding how the microbial structure in soil
under no-till farming are related to agricultural practices and soil
properties. Three treatments were defined according to land use: 1) Sustainable
agricultural management, subjected to intensive crop rotation and nutrient
amendment, 2) Non-sustainable agricultural management with high mono-cropping
without nutrient reposition, 3) Natural environment. Blocks of treatments were
replicated 4 times in agricultural fields that had documented history of
no-till management, at sites located across a west-east transect in Argentina's
Pampas. Each sample was collected in triplicate, as a composite of 16 soil subsamples
from 0-10 cm depth collected at 50 m intervals. The relative abundance of major
taxonomic groups of bacteria was estimated using primer-specific quantitative PCR and
PCRDGGE. Pseudomonads were evaluated by quantifying the culturable fraction and
by molecular markers oprF and gacA. Fatty acids profile, phosphatase and
Glomaline Related Soil Proteins (GRSP) were also surveyed along with key soil
variables (pH, moisture, organic carbon content, total nitrogen and P).
Multivariate analysis was used to analyze microbial soil biology data. Differences
in physicochemical and biochemical parameters were more consistently related to
agricultural practices than bacterial community data. Principal component
analysis separated soil management independently of site. Patterns of
significant differences between treatments were obtained at the broad level of
taxonomic resolution examined, but for most taxonomic groups the differences
were site-specific. The results indicate that no-till systems support
distinctive bacterial community composition and function according to land
management, although the significance of these differences as indicators of
soil quality requires further exploration.