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

PÉREZ BRANDÁN C.; ARZENO J. L; HUIDOBRO J; CONFORTO C.; GRUMBERG B.; HILTON S.; BENDING G.D.; MERILES J. M.; VARGAS GIL S.

SPANISH JOURNAL OF AGRICULTURAL RESEARCH

SPANISH NATL INST AGRICULTURAL & FOOD RESEARCH & TECHNOLO

Lugar: Madrid; Año: 2014 vol. 12 p. 252 - 264

1695-971X

The effect of crop sequences on soil quality indicators and its relationship with sudden25 death syndrome (SDS, a complex of Fusarium species) was evaluated by physical, chemical,26 biochemical and molecular techniques. Regarding physical aspects, soybean/maize and maize27 monoculture exhibited the highest stable aggregate level, with values 41% and 43% higher28 than in soybean monoculture, respectively, and 133% higher than in bean monoculture. Bulk29 density (BD) was higher in soybean monoculture, being 4% higher than in bean monoculture.30 The chemical parameters organic matter, total N, P, K, Mg, Ca, and water holding capacity31 also indicated that soybean/maize and maize monoculture improved soil quality. Fungal and32 bacterial community fingerprints generated using Terminal Restriction Fragment Length33 Polymorphism analysis of intergenic transcribed spacer regions of rRNA genes and 16S3rRNA genes, respectively, indicated a clear separation between the rotations. 1 Fatty acid2 profiles evaluated by FAME showed that bean monoculture had higher biomass of Gram (+)3 bacteria and stress indicators than maize monoculture, while the soybean/maize system4 showed a significant increase in total microbial biomass (total FAMEs content) in comparison5 with soybean and bean monoculture. The incidence of SDS (Fusarium crassistipitatum) was6 markedly higher (15%) under soybean monoculture than when soybean was grown in rotation7 with maize. In the present work, soil microbial properties were improved under8 soybean/maize relative to continuous soybean. The improvement of soil health was one of the9 main causes for the reduction of disease pressure and crop yield improvement due to the10 benefits that crop rotation produces for soil quality.