Geostatistical analysis was conducted for the root distribution of Vitis berlandieri x Vitis riparia using dispersion index, fractal dimension, autocorrelation and semivariance. The data were derived from the observation of roots of six 12-year old Riesling/5C vine plants in a field experiment using minirhizothron technique. The dispersion index (DI) indicated the clustering of roots. Autocorrelation as a function of the distance lag showed that a higher DI was related to higher autocorrelation at small lags. Small scale (< 3cm) spatial analysis using variograms, showed a clustering of roots at short distances (< 6cm), but also a periodicity at greater distances (16cm) with hole effects in the variograms. The spatial variance for small scale was 60-85% within a range of 5-8cm. At medium scale (5-10cm) the spatial variance decreased to 0-20%. Geostatistical analysis is a useful tool to demonstrate variation in root distribution at plant level and to improve root sampling. Although the different geostatistical tools were related, it was not possible to deduce one result from the other quantitatively.

Vineyard soils show an increased risk of degradation due to being intensively cultivated. The preservation of soil integrity and fertility is a key concept of organic and biodynamic farming. However, both systems are also subject to criticism due to their higher amount of plant protection products used and their increased traffic intensity compared to integrated viticulture, both detrimental to soil quality. The aim of this study was therefore to assess long-term effects of these three management systems on chemical and physical soil quality parameters. For this purpose, topsoil samples were taken in a long-term field trial vineyard at different positions and examined for bulk density, available water capacity (AWC), soil organic carbon (SOC), N, pH, and for total and bioavailable copper (Cu) concentrations. Biodynamic plots had a lower bulk density and higher SOC concentration than the integrated ones, which is probably due to the species-rich cover crop mixture used in the inter-row. However, organic and biodynamic farming showed an accumulation of copper in the under-vine area and in the tractor track, which is problematic for soil fertility in the long-term. Therefore, alternatives for copper in plant protection are necessary to ensure sustainable soil quality through organic and biodynamic viticulture.