Soil microbial fertility in olive orchards managed by a set of sustainable agricultural practices

n conventional olive growing, the frequent tillage has reduced soil organic matter content. Recently, soil conservation is becoming a priority in management strategies of rural areas due to the awareness of the deterioration of this natural resource and of the difficulty of its recovery in short periods (i.e. cross compliance concept in European Union). Therefore, the conventional agronomic practices should evolve to a more sustainable olive management to improve soil quality and water saving. A better understanding of soil ecology could lead to identify agricultural management practices that support and stimulate soil organisms for beneficial purposes in agriculture. The aim of this study was to evaluate the effects of sustainable practices (grass cover and pruning residues recycling) on soil quality in a Mediterranean olive orchard. The trials were carried out in a mature olive grove (Olea europaea L. – cv Maiatica) located in Basilicata Region (Southern Italy) and managed according to two different soil management systems: the sustainable treatment (ST) and the conventional treatment (CT). Soil microbiological quality in the two systems was monitored by both microbiological cultural-dependent and molecular methods. In the ST olive orchard, soil microbiota showed a higher complexity and metabolic diversity. The adoption of ‘innovative’, sustainable, agricultural practices had positive effects on soil microbiota and its biodiversity which can influence soil fertility and plant growth by increasing nutrients availability and turnover. The results of this study encourage the use of sustainable agricultural practices able to enhance soil fertility and promote good-quality fruit production without detrimental effects on water and soil resources.