Soybean fungal soil-borne diseases: a parameter for measuring the effect of agricultural intensification on soil health

CAROLINA PEREZ BRANDÁN; JORGELINA HUIDOBRO; BETIANA GRÜMBERG; MERCEDES SCANDIANI; ALICIA LUQUE; JOSE MERILES; SILVINA VARGAS GIL

CANADIAN JOURNAL OF MICROBIOLOGY

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Otawa; Año: 2014

0008-4166

The aim of this study was to investigate the influence of agricultural intensification on soil microbial diversity,chemical and physical parameters, and the decrease of the incidence of sudden death syndrome (Fusarium crassistipitatum) andcharcoal rot (Macrophomina phaseolina) in soybean. Soils under different management systems were evaluated during 2 cropcycles: soybean monoculture for 24 and 11 years, soybean?maize rotation for 15 and 4 years, 1 year of soybean, and nativevegetation. The incidence of both soil-borne diseases was higher under monoculture than under rotation. Increased populationsof potential biocontrol agents (Trichoderma spp., Gliocladium spp., fluorescent pseudomonads) were associated with rotationtreatments, especially in 2010?2011. The comparison of agricultural vs. native vegetation soil and the average of agriculturalcycles showed that microbial biomass carbon and glomalin-related soil protein were higher in the rotation system than inmonoculture (50% and 77%, respectively). Furthermore, from the community-level functional diversity (Biolog Eco plates),McIntosh index showed lower functional diversity in monoculture than in rotation and native vegetation plots. Agriculturalintensification reduced microbial biomass carbon, glomalin-related soil protein, organic matter, total nitrogen, aggregatestability, and yield, and increased bulk density. Soil quality degradation was associated with the establishment of soil-bornepathogens and increased soybean plant susceptibility to disease.