Compactionof sloping vineyard soil by tractor traffic and its effects on spatial distribuition of penetration resistence and water content

The effects of tractor traffic across the slope on spatial distribution of soil strength and water content in traditionally tilled and controlled grass covered vineyard were investigated. The experiment was situated on hillside vineyard (NW Italy ) with average slope of 20% on silt loam soil. The results were analysed using classic statistics and geostatistics. The highest variability was obtained for penetration resistance (CV 56.6%) and the lowest for bulk density (9.6%). In most cases semivariograms of the soil parameters were well described by sphericalmodels. 3D maps well identified areas with high soi l strength in lower tractor ruts being positioned in the upper side of vine row and lower strength in upper ruts situated on other side of the same row down slope. Soil water conteni in both treatments was the lowest below the upper rut and increased in inter-rut and lower rut areas.