Assessment of soil restoration using organic conditioners to improve vineyard soil health

Maintaining soil fertility and organic matter is pivotal in ensuring the sustainability of vineyards. In order to assess the implementation of advanced agronomic techniques and soil regeneration products, an interdisciplinary approach is imperative. In this context, it is crucial to make a conscious choice regarding the methodology to be employed and the selection of appropriate indicators. In a prestigious vineyard in Montalcino (Siena, Italy), a three-year trial was carried out by application of a registered vermicomposting digestate and a peculiar interrow soil management. The research encompassing a comprehensive array of investigative procedures during the years, as proximal sensor surveys, soil analyses, soil microbial and micro-arthropod biodiversity studies, and eco-physiological plant assessments. The results of the study showed, in the treated area, an increase in organic carbon content and a subsequent reduction in soil pH. Indeed also electrical conductivity exhibited an increase, although it remains well below the tolerable level for vines. Nonetheless, it is advisable to consider this parameter in moderately saline soils. The bacterial community seems to be influenced by a position effect. Nevertheless the culturable component exhibited a significant increase throughout the vineyard during the trial period, with a particularly notable rise observed in the treated area in the final year of treatment. Subsequent total bacterial DNA analysis of soil samples collected in the second year revealed that the treated soils exhibited a marginally higher relative abundance of the bacterial genera Methylotenera and Streptomyces, which are recognised for their role in nutrient cycling and as plant growth promoters. Like culturable bacteria, analysis of the microarthropod community demonstrated an increase in population over time in both the treated and control areas, but the increase was higher and with low variability in treated area. Regarding the vines in the treated area, they showed increased levels of productive activity, as carbon assimilation rates and enhanced efficiency in the utilisation of water for photosynthesis. Furthermore, an increased structural consistency in the leaves was observed, leading to enhanced resistance to water stress. In conclusion, the results confirmed the effectiveness of this strategy as a possible tool to improve soil health, without significant negative impacts on the analysed parameters. However, soil regeneration is a protracted process, necessitating a tailored approach to each site. This assessment pattern is regarded as a sustainable model for the management of wine-growing soils; however, further studies are recommended to evaluate its applicability on a larger scale and on different soil types.