Establishment of three cover crop mixtures in vineyards

Developing sustainable farming practices to support ecosystem functions and services are key issues of agro-ecology and conservation biology. In organic wine production, preserving soil fertility and weed control are essential tasks, because the use of synthetically processed herbicides, pesticides and fertilizers is strongly limited. Thus, it is vital to propose and test alternative techniques to link issues of weed control, preservation of soil fertility and the improvement and conservation of agro-biodiversity. To fulfil these issues, the use of species-rich cover crops became increasingly integrated into organic wine production. We evaluated the establishment of three vineyard cover crop seed mixtures sown in the vineyards of the Tokaj region, East-Hungary to answer the following questions: (i) which sown species were successfully established during the first year after sowing? (ii) Which sown species established successfully even during the second year? (iii) How effective were the sown cover crop seed mixtures in weed control? We evaluated three types of species-rich seed mixtures: Biocont-ECOWIN, Grass-medical forb and Legume seed mixtures. Percentage cover of vascular plant species was recorded in the inter-rows in five 1 × 1 m permanent plots in late June, 2012 and 2013. All sown species established within the study period. During the first year mostly short-lived species established successfully from the sown seed mixtures. During the second year Lotus corniculatus, Medicago lupulina, Plantago lanceolata, Trifolium repens and Trifolium pratense established the most successfully, and had high cover scores at most sites out of the sown species. A significant weed suppression was detected for all sown mixtures (Biocont-ECOWIN seed mixture: at two sites; Grass-medical forb seed mixture: at every site; Legume seed mixture: at two sites). The magnitude of weed suppression varied with the sown seed mixture. During the first year Biocont-ECOWIN seed mixture was the most successful in weed suppression. During the second year the cover of weeds was suppressed most effectively by Grass-medical forb and Legume seed mixtures. Our findings suggest that high diversity seed mixtures are suitable to establish permanent cover crops, which enables to use them successfully at sites with different abiotic conditions.