CONICET | Buscador de Institutos y Recursos Humanos

INFLUENCE OF DIFFERENT SOIL MANAGEMENT SYSTEMS ON SOIL MITES (ARACHNIDA: ACARI) DENSITY IN AGROECOSYSTEMS OF CORDOBA, ARGENTINA.The aim of this work was to evaluate the influence of soil management on soil mite densities inagroecosystems of La Colacha basin (Córdoba, Argentina). Soil Acari community in four systems with different soil disturbance degree was studied. Soil samples were taken bimonthly, from August 1999 to June 2000, in an undisturbed natural system (NA), in a beef cattle production system (GA), in a rotational plot (MI) and in a conventional tillage crop production system (AG). Six samples by system were taken in each sampling date for mite extraction. Additionally, two composite soil samples were taken at random in each system to evaluate chemical, physical, and physicochemical soil properties. Differences in soil moisture, temperature and organic matter content were observed between the two more intensively managed systems and the others. In one sampling date, mite density response agreed in part with the expected pattern of lower density in intensive managed systems: NA and CA plots showed the highest values, followed by MI and AG, but differences only were statistically significant between NA and CA with MI. In two months, the highest density was found in the GA plot and in other two months, GA showed higher density than NA and MI. Although not definitive proof of the hypothesis, these data are consistent with the suggestions of others that intensive management systems tend to reduce soil mites density. However, the diminution of soil mites density as a result of intensive soil management could not be verified in all samplings. Some authors suggested that the effect of tillage on mites is different for different taxa. This can be theexplanation of the variable response of overall Acari density to soil cultivation practices showed in this work.

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