Groundcover Mulching in Mediterranean Vineyards Improves Soil Chemical, Physical and Biological Health Already in the Short Term

Vineyards are among the land uses with the highest soil degradation rate in Mediterranean Europe, mainly due to intensive tillage management. Therefore, practices able to foster soil health are critical to promote sustainable wine production. We studied the following treatments in two organic farms in Chianti Classico (Italy): conventional tillage, spontaneous vegetation, pigeon bean (Vicia faba var. minor) incorporated in spring and a mixture of barley (Hordeum vulgare) and squarrosum clover (Trifolium squarrosum), both incorporated and left as mulch. An innovative approach, based on gamma-ray and apparent electrical conductivity, was used to account for the fine-scale soil variability that was included in the statistical model. Mulched groundcovers were associated with higher soil organic matter compared to tillage, already after two years. An increased N availability was found under all groundcovers compared with tillage. The effect of soil management practices on P2O5 strongly varied across farms and years, while it was not statistically significant on K availability. Spontaneous vegetation positively influenced the soil structure index, soil penetration resistance and soil biological health. The results show that mulched groundcovers can improve soil health already in the short term, thereby potentially increasing the sustainability of the wine sector.