The effect of crop sequences on soil microbial, chemical and physical indicators and its relationship with soybean sudden death syndrome (complex of Fusarium species)

CAROLINA PEREZ BRANDÁN; JOSE LUIS ARZENO; JORGELINA HUIDOBRO; CINTHIA CONFORTO; BETIANA GRÜMBERG; SALLY HILTON; GARY BENDING; JOSE MERILES; SILVINA VARGAS GIL

SPANISH JOURNAL OF AGRICULTURAL RESEARCH

SPANISH NATL INST AGRICULTURAL & FOOD RESEARCH & TECHNOLO

Lugar: Madrid; Año: 2014

1695-971X

The effect of crop sequences on soil quality indicators and its relationship with sudden death syndrome (SDS, acomplex of Fusarium species) was evaluated by physical, chemical, biochemical and molecular techniques. Regardingphysical aspects, soybean/maize and maize monoculture exhibited the highest stable aggregate level, with values 41%and 43% higher than in soybean monoculture, respectively, and 133% higher than in bean monoculture. Bulk density(BD) was higher in soybean monoculture, being 4% higher than in bean monoculture. The chemical parameters organicmatter, total N, P, K, Mg, Ca, and water holding capacity also indicated that soybean/maize and maize monocultureimproved soil quality. Fungal and bacterial community fingerprints generated using Terminal Restriction FragmentLength Polymorphism analysis of intergenic transcribed spacer regions of rRNA genes and 16S rRNA genes, respectively,indicated a clear separation between the rotations. Fatty acid profiles evaluated by FAME showed that bean monoculturehad higher biomass of Gram (+) bacteria and stress indicators than maize monoculture, while the soybean/maize systemshowed a significant increase in total microbial biomass (total FAMEs content) in comparison with soybean and beanmonoculture. The incidence of SDS (Fusarium crassistipitatum) was markedly higher (15%) under soybean monoculturethan when soybean was grown in rotation with maize. In the present work, soil microbial properties were improvedunder soybean/maize relative to continuous soybean. The improvement of soil health was one of the main causes forthe reduction of disease pressure and crop yield improvement due to the benefits that crop rotation produces for soilquality.