Resumen

COVACEVICH, Fernanda; EYHERABIDE, Mercedes; SAINZ ROZAS, Hernán  y  ECHEVERRIA, Hernán Eduardo. Chemical characteristics as determinants of arbuscular mycotrophic ability of agricultural and pristine soils from Buenos Aires (Argentina). Cienc. suelo [online]. 2012, vol.30, n.2, pp.119-128. ISSN 1850-2067.

The soils of Buenos Aires Province (Argentina) have very good physical and chemical properties for agricultural production, and also a high microbial diversity. However, the continuous cropping of agricultural soils with a high nutrient removal rate has accelerated its degradation. Consequently, the soils' natural fertility and the beneficial microbial populations such as arbuscular mycorrhizal fungi (AMF) could be affected. The objective of this study was to identify changes in the nutrient content in soils under contrasting managements (agricultural vs. pristine) that could influence the mycotrophic ability of AMF. Soil samples were collected from 29 agricultural sites in Buenos Aires Province under cropped and non-cropped (pristine) systems. Chemical characteristics were determined (CIC, Fe, Mn, Cu, Zn, B, P-Bray, CO and pH) in composed samples collected from each field. Mycotrophic ability was estimated by assessing the degree of root colonization by native mycorrhiza in trap crops after 12 weeks of sowing. The values of chemical properties were generally higher for pristine sites than for agricultural plots. However, the mycotrophic ability did not differ between cropped and pristine soils. The principal component analysis allowed grouping field sites under agriculture or pristine conditions. Soil available P content, together with Fe and to a lesser extent Mn content- seemed to depress the mycotrophic ability of the analyzed soil, particularly under moderate to low organic carbon contents conditions.

Palabras clave : Arbuscular mycorrhiza; Infective capacity; Soil nutrients; Soil management.

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