Assessment and restoring soil functionality in degraded areas of organic vineyards. The preliminary results of the ReSolVe project in Italy

Summary

In both conventional and organic Italian vineyards, it is quite common to have areas characterized by problems in
vine health, grape production and quality, often caused by improper land preparation before vine plantation and/or
management. Causes for soil malfunctioning can include: reduced contribution of the soil fauna to the ecosystem
services (i.e. nutrient cycles), poor organic matter content, imbalance of some element ratio, altered pH, water
deficiency, soil compaction and/or scarce oxygenation.
ReSolVe is a transnational and interdisciplinary 3-years research project aimed at testing the effects of selected
organic strategies for restoring optimal soil functionality in degraded areas within vineyard. The different restoring
strategies implemented in each plot will be: i) compost produced on farm by manure + pruning residue + grass, ii)
faba bean and barley green manure, iii) sowing and dry mulching with Trifolium squarrosum L. During two years
of such treatments, the trend of the soil features and the grapevine status will be monitored in detail, to reveal the
positive and negative effects of such treatments.
The project involves 8 research groups in 6 different EU countries (Italy, France, Spain, Sweden, Slovenia,
and Turkey), with experts from several disciplines, including soil science, ecology, microbiology, grapevine
physiology, viticulture, and biometry. The experimental vineyards are situated in Italy (Chianti hills and Maremma
plain, Tuscany), France (Bordeaux and Languedoc), Spain (La Rioja) and Slovenia (Primorska) for winegrape,
and in Turkey (Adana and Mersin) for table grape.
Soil features before implementing restoring strategies showed lower content of soil organic matter and enzyme
activities, and higher carbonates in degraded areas than in the non-degraded areas. The Biological Soil Quality
values of microarthropods were always high, in comparison with data registered in similarly managed vineyards
or stable ecosystems, and the data showed homogeneous patterns within the experimental plots.
Nematode abundance, taxa richness and maturity (MI) and plant parasitic (PPI) indices were higher in nondegraded
than degraded areas, but differences were not significant. Grapevines in degraded areas of both farms
showed less vegetative vigour and significantly lower values in the SPAD colour index. The yield and the weight
of the grape bunches and berries were greater in the not degraded. The grapes of degraded areas at harvest had
instead a sugar content significantly higher (on average +2.5�Brix).
The restoration techniques and the monitoring methodologies developed and tested during the ReSolVe project will
be described in specific final guidelines. The restoration techniques will be accessible for all the European farmers
and will be low cost and environmental-friendly. A protocol of analyses and measurements between the all partners
will allow an effective and comparable monitoring of vineyard ecosystemic functioning in European countries.